Add testing

- This brings in the flow test suite that contains a ton of JavaScript parsing edge cases
- This creates snapshot tests using the pretty printer for all of them
- If uncomment `RUN_AST_TESTS` line in `tests/run_specs.js`, it checks ast(pretty_print(x)) == ast(x). Right now, "178 failed, 197 passed, 375 of 377 total". So half of the tests are not passing, most of them are crashes and many of the rest are subtle issues.

package.json

@@ -11,6 +11,19 @@
     "recast": "^0.11.18"
   },
   "devDependencies": {
-    "glob": "^7.1.1"
+    "glob": "^7.1.1",
+    "jest": "^18.0.0",
+    "flow-parser": "^0.37.0"
+  },
+  "scripts": {
+    "test": "jest"
+  },
+  "jest": {
+    "setupFiles": [
+      "<rootDir>/tests_config/run_spec.js"
+    ],
+    "testRegex": [
+      "jsfmt\\.spec\\.js$"
+    ]
   }
 }

tests/abnormal/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,127 @@
+exports[`test break-continue.js 1`] = `
+"function foo() {
+    while(true) { break; }
+}
+
+function bar() {
+    L: do { continue L; } while(false)
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:925
+      if (endsWithBrace(doBody))
+          ^
+
+ReferenceError: endsWithBrace is not defined
+    at genericPrintNoParens (/src/printer.js:925:11)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:963:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test return.js 1`] = `
+"function bar(x:number) { }
+function foo() {
+    var x = null;
+    if (x == null) return;
+    bar(x);
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+function bar(x: number) {
+  
+}
+function foo() {
+  var x = null;
+  if (x == null)
+    return;
+  bar(x);
+}
+
+"
+`;
+
+exports[`test toplevel_break.js 1`] = `
+"// @flow
+
+break; // error, illegal
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unsyntactic break (3:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp$1.parseBreakContinueStatement (/node_modules/babylon/lib/index.js:1843:44)
+    at Parser.pp$1.parseStatement (/node_modules/babylon/lib/index.js:1703:19)
+    at Parser.parseStatement (/node_modules/babylon/lib/index.js:5224:22)
+    at Parser.pp$1.parseBlockBody (/node_modules/babylon/lib/index.js:2139:21)
+    at Parser.pp$1.parseTopLevel (/node_modules/babylon/lib/index.js:1651:8)
+    at Parser.parse (/node_modules/babylon/lib/index.js:1543:17)
+    at Object.parse$1 [as parse] (/node_modules/babylon/lib/index.js:6472:37)
+    at Object.parse (/index.js:34:26)
+    at Object.parse (/node_modules/recast/lib/parser.js:26:34)
+"
+`;
+
+exports[`test toplevel_continue.js 1`] = `
+"// @flow
+
+continue; // error, illegal
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unsyntactic continue (3:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp$1.parseBreakContinueStatement (/node_modules/babylon/lib/index.js:1843:44)
+    at Parser.pp$1.parseStatement (/node_modules/babylon/lib/index.js:1703:19)
+    at Parser.parseStatement (/node_modules/babylon/lib/index.js:5224:22)
+    at Parser.pp$1.parseBlockBody (/node_modules/babylon/lib/index.js:2139:21)
+    at Parser.pp$1.parseTopLevel (/node_modules/babylon/lib/index.js:1651:8)
+    at Parser.parse (/node_modules/babylon/lib/index.js:1543:17)
+    at Object.parse$1 [as parse] (/node_modules/babylon/lib/index.js:6472:37)
+    at Object.parse (/index.js:34:26)
+    at Object.parse (/node_modules/recast/lib/parser.js:26:34)
+"
+`;
+
+exports[`test toplevel_return.js 1`] = `
+"// @flow
+
+return; // error, illegal
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: \'return\' outside of function (3:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp$1.parseReturnStatement (/node_modules/babylon/lib/index.js:1939:10)
+    at Parser.pp$1.parseStatement (/node_modules/babylon/lib/index.js:1722:19)
+    at Parser.parseStatement (/node_modules/babylon/lib/index.js:5224:22)
+    at Parser.pp$1.parseBlockBody (/node_modules/babylon/lib/index.js:2139:21)
+    at Parser.pp$1.parseTopLevel (/node_modules/babylon/lib/index.js:1651:8)
+    at Parser.parse (/node_modules/babylon/lib/index.js:1543:17)
+    at Object.parse$1 [as parse] (/node_modules/babylon/lib/index.js:6472:37)
+    at Object.parse (/index.js:34:26)
+    at Object.parse (/node_modules/recast/lib/parser.js:26:34)
+"
+`;
+
+exports[`test toplevel_throw.js 1`] = `
+"// @flow
+
+throw new Error(\'foo\'); // no error
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// @flow
+throw new Error(\"foo\");// no error
+
+"
+`;

tests/abnormal/break-continue.js

@@ -0,0 +1,7 @@
+function foo() {
+    while(true) { break; }
+}
+
+function bar() {
+    L: do { continue L; } while(false)
+}

tests/abnormal/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/abnormal/return.js

@@ -0,0 +1,6 @@
+function bar(x:number) { }
+function foo() {
+    var x = null;
+    if (x == null) return;
+    bar(x);
+}

tests/abnormal/toplevel_break.js

@@ -0,0 +1,3 @@
+// @flow
+
+break; // error, illegal

tests/abnormal/toplevel_continue.js

@@ -0,0 +1,3 @@
+// @flow
+
+continue; // error, illegal

tests/abnormal/toplevel_return.js

@@ -0,0 +1,3 @@
+// @flow
+
+return; // error, illegal

tests/abnormal/toplevel_throw.js

@@ -0,0 +1,3 @@
+// @flow
+
+throw new Error('foo'); // no error

tests/annot/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,234 @@
+exports[`test annot.js 1`] = `
+"function foo(str:string, i:number):string {
+  return str;
+}
+var bar: (str:number, i:number)=> string = foo;
+
+var qux = function(str:string, i:number):number { return foo(str,i); }
+
+var obj: {str:string; i:number; j:boolean} = {str: \"...\", i: \"...\", k: false};
+
+var arr: Array<number> = [1,2,\"...\"];
+
+// array sugar
+var array: number[] = [1,2,\"...\"];
+
+var matrix: number[][] = [[1,2],[3,4]];
+var matrix_parens: (number[])[] = matrix;
+
+var nullable_array: ?number[] = null;
+var nullable_array_parens: ?(number[]) = nullable_array;
+
+var array_of_nullable: (?number)[] = [null, 3];
+
+var array_of_tuple: [number, string][] = [[0, \"foo\"], [1, \"bar\"]];
+var array_of_tuple_parens: ([number, string])[] = array_of_tuple;
+
+type ObjType = { \'bar-foo\': string; \'foo-bar\': number; };
+var test_obj: ObjType = { \'bar-foo\': \'23\' };
+
+// param type annos are strict UBs like var type annos
+function param_anno(n:number):void {
+  n = \"hey\"; // error
+}
+
+// another error on param UB, more typical of www (mis)use-cases
+// this one cribbed from API.atlas.js
+function param_anno2(
+    batchRequests: Array<{method: string; path: string; params: ?Object}>,
+  ): void {
+
+    // error below, since we\'re assigning elements to batchRequests
+    // which lack a path property.
+    // just assign result to new var instead of reassigning to param.
+
+    // Transform the requests to the format the Graph API expects.
+    batchRequests = batchRequests.map((request) => {
+      return {
+        method: request.method,
+        params: request.params,
+        relative_url: request.path,
+      };
+    });
+    // ...
+  }
+
+var toz : null = 3;
+
+var zer : null = null;
+
+function foobar(n : ?number) : number | null | void { return n; }
+function barfoo(n : number | null | void) : ?number { return n; }
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1348
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1348:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1254:25)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test forward_ref.js 1`] = `
+"let myClassInstance: MyClass = null; // forward ref ok, null ~> class error
+
+function bar(): MyClass {
+  return null; // forward ref ok, null ~> class error
+}
+
+class MyClass { } // looked up above
+
+function foo() {
+  let myClassInstance: MyClass = mk(); // ok (no confusion across scopes)
+  function mk() { return new MyClass(); }
+
+  class MyClass { } // looked up above
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+let myClassInstance: MyClass = null;// forward ref ok, null ~> class error
+function bar(): MyClass {
+  return null;// forward ref ok, null ~> class error
+}
+class MyClass {}// looked up above
+function foo() {
+  let myClassInstance: MyClass = mk();// ok (no confusion across scopes)
+  function mk() {
+    return new MyClass();
+  }
+  class MyClass {}// looked up above
+}
+
+"
+`;
+
+exports[`test issue-530.js 1`] = `
+"function foo(...args: any) { }
+
+module.exports = foo;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+function foo(...args) {
+  
+}
+module.exports = foo;
+
+"
+`;
+
+exports[`test leak.js 1`] = `
+"/** @flow */
+
+/* This test documents an example we ran into of a type annotation leaking.
+ *
+ * When foo() calls bar(), we should make sure the type of x matches the type
+ * annotation for y and stop. We should type the body of bar() with the type
+ * annotation of y.
+ *
+ * However, the leaky type annotation meant that we were flowing x\'s type to y
+ * and type checking the body of bar() using the stricter dictionary type,
+ * leading to an error.
+ */
+
+type MyObj = Object;
+
+function foo(x: {[key: string]: mixed}) {
+  bar(x);
+}
+
+function bar(y: MyObj): string {
+  return y.foo;
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/** @flow */
+/* This test documents an example we ran into of a type annotation leaking.
+ *
+ * When foo() calls bar(), we should make sure the type of x matches the type
+ * annotation for y and stop. We should type the body of bar() with the type
+ * annotation of y.
+ *
+ * However, the leaky type annotation meant that we were flowing x\'s type to y
+ * and type checking the body of bar() using the stricter dictionary type,
+ * leading to an error.
+ */
+type MyObj = Object;
+function foo(x: { [key: string]: mixed }) {
+  bar(x);
+}
+function bar(y: MyObj): string {
+  return y.foo;
+}
+
+"
+`;
+
+exports[`test other.js 1`] = `
+"class C { }
+module.exports = (C: any);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+class C {}
+module.exports = (C: any);
+
+"
+`;
+
+exports[`test scope.js 1`] = `
+"type Merge<T> = (a: T, b: T) => T;
+
+// hypothetical immutable map
+declare class Map<K,V> {
+  (): Map<K,V>;
+  insertWith(fn: Merge<V>, k: K, v: V): Map<K,V>;
+}
+
+declare function foldr<A,B>(fn: (a: A, b: B) => B, b: B, as: A[]): B;
+
+function insertMany<K,V>(merge: Merge<V>, vs: [K,V][], m: Map<K,V>): Map<K,V> {
+  function f([k,v]: [K,V], m: Map<K,V>): Map<K,V> {
+    return m.insertWith(merge, k, v)
+  }
+  return foldr(f, m, vs)
+}
+
+class Foo<A> {
+  bar<B>() {
+    return function<C>(a: A, b: B, c: C): void {
+      ([a,b,c] : [A,B,C]);
+    }
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1479:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test test.js 1`] = `
+"var C = require(\'./other\');
+((0: C): string);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+var C = require(\"./other\");
+((0: C): string);
+
+"
+`;

tests/annot/annot.js

@@ -0,0 +1,60 @@
+function foo(str:string, i:number):string {
+  return str;
+}
+var bar: (str:number, i:number)=> string = foo;
+
+var qux = function(str:string, i:number):number { return foo(str,i); }
+
+var obj: {str:string; i:number; j:boolean} = {str: "...", i: "...", k: false};
+
+var arr: Array<number> = [1,2,"..."];
+
+// array sugar
+var array: number[] = [1,2,"..."];
+
+var matrix: number[][] = [[1,2],[3,4]];
+var matrix_parens: (number[])[] = matrix;
+
+var nullable_array: ?number[] = null;
+var nullable_array_parens: ?(number[]) = nullable_array;
+
+var array_of_nullable: (?number)[] = [null, 3];
+
+var array_of_tuple: [number, string][] = [[0, "foo"], [1, "bar"]];
+var array_of_tuple_parens: ([number, string])[] = array_of_tuple;
+
+type ObjType = { 'bar-foo': string; 'foo-bar': number; };
+var test_obj: ObjType = { 'bar-foo': '23' };
+
+// param type annos are strict UBs like var type annos
+function param_anno(n:number):void {
+  n = "hey"; // error
+}
+
+// another error on param UB, more typical of www (mis)use-cases
+// this one cribbed from API.atlas.js
+function param_anno2(
+    batchRequests: Array<{method: string; path: string; params: ?Object}>,
+  ): void {
+
+    // error below, since we're assigning elements to batchRequests
+    // which lack a path property.
+    // just assign result to new var instead of reassigning to param.
+
+    // Transform the requests to the format the Graph API expects.
+    batchRequests = batchRequests.map((request) => {
+      return {
+        method: request.method,
+        params: request.params,
+        relative_url: request.path,
+      };
+    });
+    // ...
+  }
+
+var toz : null = 3;
+
+var zer : null = null;
+
+function foobar(n : ?number) : number | null | void { return n; }
+function barfoo(n : number | null | void) : ?number { return n; }

tests/annot/any/A.js

@@ -0,0 +1,9 @@
+type T = any;
+
+export default class {
+  p: T;
+
+  constructor() {
+    this.p = 0;
+  }
+}

tests/annot/any/B.js

@@ -0,0 +1,5 @@
+import A from "./A"
+
+class B extends A {
+  p: string; // OK, string ~> any
+}

tests/annot/any/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,36 @@
+exports[`test A.js 1`] = `
+"type T = any;
+
+export default class {
+  p: T;
+
+  constructor() {
+    this.p = 0;
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+type T = any;
+export default class {
+  p: T;
+  constructor() {
+    this.p = 0;
+  }
+}
+
+"
+`;
+
+exports[`test B.js 1`] = `
+"import A from "./A"
+
+class B extends A {
+  p: string; // OK, string ~> any
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+import A from "./A";
+class B extends A {
+  p: string;// OK, string ~> any
+}
+
+"
+`;

tests/annot/any/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/annot/forward_ref.js

@@ -0,0 +1,14 @@
+let myClassInstance: MyClass = null; // forward ref ok, null ~> class error
+
+function bar(): MyClass {
+  return null; // forward ref ok, null ~> class error
+}
+
+class MyClass { } // looked up above
+
+function foo() {
+  let myClassInstance: MyClass = mk(); // ok (no confusion across scopes)
+  function mk() { return new MyClass(); }
+
+  class MyClass { } // looked up above
+}

tests/annot/issue-530.js

@@ -0,0 +1,3 @@
+function foo(...args: any) { }
+
+module.exports = foo;

tests/annot/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/annot/leak.js

@@ -0,0 +1,22 @@
+/** @flow */
+
+/* This test documents an example we ran into of a type annotation leaking.
+ *
+ * When foo() calls bar(), we should make sure the type of x matches the type
+ * annotation for y and stop. We should type the body of bar() with the type
+ * annotation of y.
+ *
+ * However, the leaky type annotation meant that we were flowing x's type to y
+ * and type checking the body of bar() using the stricter dictionary type,
+ * leading to an error.
+ */
+
+type MyObj = Object;
+
+function foo(x: {[key: string]: mixed}) {
+  bar(x);
+}
+
+function bar(y: MyObj): string {
+  return y.foo;
+}

tests/annot/other.js

@@ -0,0 +1,2 @@
+class C { }
+module.exports = (C: any);

tests/annot/scope.js

@@ -0,0 +1,24 @@
+type Merge<T> = (a: T, b: T) => T;
+
+// hypothetical immutable map
+declare class Map<K,V> {
+  (): Map<K,V>;
+  insertWith(fn: Merge<V>, k: K, v: V): Map<K,V>;
+}
+
+declare function foldr<A,B>(fn: (a: A, b: B) => B, b: B, as: A[]): B;
+
+function insertMany<K,V>(merge: Merge<V>, vs: [K,V][], m: Map<K,V>): Map<K,V> {
+  function f([k,v]: [K,V], m: Map<K,V>): Map<K,V> {
+    return m.insertWith(merge, k, v)
+  }
+  return foldr(f, m, vs)
+}
+
+class Foo<A> {
+  bar<B>() {
+    return function<C>(a: A, b: B, c: C): void {
+      ([a,b,c] : [A,B,C]);
+    }
+  }
+}

tests/annot/test.js

@@ -0,0 +1,2 @@
+var C = require('./other');
+((0: C): string);

tests/annot2/A.js

@@ -0,0 +1,14 @@
+/**
+ * @providesModule A
+ * @flow
+ */
+
+import type T from "T";
+
+export default class {
+  p: T;
+
+  constructor() {
+    this.p = 0;
+  }
+}

tests/annot2/B.js

@@ -0,0 +1,9 @@
+/**
+ * @flow
+ */
+
+import A from "A"
+
+class B extends A {
+  p: string; // OK, string ~> any
+}

tests/annot2/T.js

@@ -0,0 +1,3 @@
+/**
+ * @providesModule T
+ */

tests/annot2/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,62 @@
+exports[`test A.js 1`] = `
+"/**
+ * @providesModule A
+ * @flow
+ */
+
+import type T from "T";
+
+export default class {
+  p: T;
+
+  constructor() {
+    this.p = 0;
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/**
+ * @providesModule A
+ * @flow
+ */
+import type T from "T";
+export default class {
+  p: T;
+  constructor() {
+    this.p = 0;
+  }
+}
+
+"
+`;
+
+exports[`test B.js 1`] = `
+"/**
+ * @flow
+ */
+
+import A from "A"
+
+class B extends A {
+  p: string; // OK, string ~> any
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/**
+ * @flow
+ */
+import A from "A";
+class B extends A {
+  p: string;// OK, string ~> any
+}
+
+"
+`;
+
+exports[`test T.js 1`] = `
+"/**
+ * @providesModule T
+ */
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+
+"
+`;

tests/annot2/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/any/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,202 @@
+exports[`test any.js 1`] = `
+"// @flow
+
+function foo(x:any):any { return x; }
+function bar(x:any):mixed { return x; }
+function qux(x:mixed):any { return x; }
+
+var x:string = foo(0);
+var y:string = bar(0);
+var z:string = qux(0);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// @flow
+function foo(x: any): any {
+  return x;
+}
+function bar(x: any): mixed {
+  return x;
+}
+function qux(x: mixed): any {
+  return x;
+}
+var x: string = foo(0);
+var y: string = bar(0);
+var z: string = qux(0);
+
+"
+`;
+
+exports[`test anyexportflowfile.js 1`] = `
+"// @flow
+
+module.exports = ((x: any) => x: any);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// @flow
+module.exports = ((x: any) => x: any);
+
+"
+`;
+
+exports[`test flowfixme.js 1`] = `
+"/*
+  FlowFixMe is a synonym for any, used by the Flow team to
+  signal a needed mod to JS devs.
+
+  @flow
+ */
+
+// no param
+function foo(x:$FlowFixMe):$FlowFixMe { return x; }
+function bar(x:$FlowFixMe):mixed { return x; }
+// param (info only)
+function qux(x:$FlowFixMe<number>):$FlowFixMe<number> { return x; }
+// ...params are still checked. unknown type
+function baz(x:$FlowFixMe<nnumber>): $FlowFixMe<number> { return x; }
+
+var x:string = foo(0);
+var y:string = bar(0);
+var z:string = qux(0);
+var w:string = baz(0);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test flowissue.js 1`] = `
+"/*
+  $FlowIssue is a synonym for any, used by JS devs to signal
+  a potential typechecker bug to the Flow team.
+
+  @flow
+ */
+
+// no param
+function foo(x:$FlowIssue):$FlowIssue { return x; }
+function bar(x:$FlowIssue):mixed { return x; }
+// param (info only)
+function qux(x:$FlowIssue<number>):$FlowIssue<number> { return x; }
+// ...params are still checked. unknown type
+function baz(x:$FlowIssue<nnumber>): $FlowIssue<number> { return x; }
+
+var x:string = foo(0);
+var y:string = bar(0);
+var z:string = qux(0);
+var w:string = baz(0);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test nonflowfile.js 1`] = `
+"// @noflow
+
+module.exports = (x) => x;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// @noflow
+module.exports = x => x;
+
+"
+`;
+
+exports[`test propagate.js 1`] = `
+"// @flow
+
+declare class C {
+  bar(n1: number, n2: number): number;
+  bar(s1: string, s2: string): string;
+}
+
+function foo(c: C, x: any): string {
+  let y = x.y;
+  return c.bar(0, y); // should be able to select first case and error
+}
+
+var any_fun1 = require(\'./nonflowfile\');
+function bar1(x: mixed) {
+  if (any_fun1(x)) {
+    (x: boolean);
+  }
+}
+
+var any_fun2 = require(\'./anyexportflowfile\');
+function bar2(x: mixed) {
+  if (any_fun2(x)) {
+    (x: boolean);
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1348
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1348:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1452:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test reach.js 1`] = `
+"/**
+ * like class and function values, any-typed values may be used in
+ * type annotations. Here we test propagation of any through the
+ * annotation - without it, the body of the if will be unreachable 
+ */
+
+type AsyncRequest = any;
+
+function foo(o: ?AsyncRequest) {
+  if (o) {
+    var n: number = o;
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/**
+ * like class and function values, any-typed values may be used in
+ * type annotations. Here we test propagation of any through the
+ * annotation - without it, the body of the if will be unreachable 
+ */
+type AsyncRequest = any;
+function foo(o: ?AsyncRequest) {
+  if (o) {
+    var n: number = o;
+  }
+}
+
+"
+`;

tests/any/any.js

@@ -0,0 +1,9 @@
+// @flow
+
+function foo(x:any):any { return x; }
+function bar(x:any):mixed { return x; }
+function qux(x:mixed):any { return x; }
+
+var x:string = foo(0);
+var y:string = bar(0);
+var z:string = qux(0);

tests/any/anyexportflowfile.js

@@ -0,0 +1,3 @@
+// @flow
+
+module.exports = ((x: any) => x: any);

tests/any/flowfixme.js

@@ -0,0 +1,19 @@
+/*
+  FlowFixMe is a synonym for any, used by the Flow team to
+  signal a needed mod to JS devs.
+
+  @flow
+ */
+
+// no param
+function foo(x:$FlowFixMe):$FlowFixMe { return x; }
+function bar(x:$FlowFixMe):mixed { return x; }
+// param (info only)
+function qux(x:$FlowFixMe<number>):$FlowFixMe<number> { return x; }
+// ...params are still checked. unknown type
+function baz(x:$FlowFixMe<nnumber>): $FlowFixMe<number> { return x; }
+
+var x:string = foo(0);
+var y:string = bar(0);
+var z:string = qux(0);
+var w:string = baz(0);

tests/any/flowissue.js

@@ -0,0 +1,19 @@
+/*
+  $FlowIssue is a synonym for any, used by JS devs to signal
+  a potential typechecker bug to the Flow team.
+
+  @flow
+ */
+
+// no param
+function foo(x:$FlowIssue):$FlowIssue { return x; }
+function bar(x:$FlowIssue):mixed { return x; }
+// param (info only)
+function qux(x:$FlowIssue<number>):$FlowIssue<number> { return x; }
+// ...params are still checked. unknown type
+function baz(x:$FlowIssue<nnumber>): $FlowIssue<number> { return x; }
+
+var x:string = foo(0);
+var y:string = bar(0);
+var z:string = qux(0);
+var w:string = baz(0);

tests/any/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/any/nonflowfile.js

@@ -0,0 +1,3 @@
+// @noflow
+
+module.exports = (x) => x;

tests/any/propagate.js

@@ -0,0 +1,25 @@
+// @flow
+
+declare class C {
+  bar(n1: number, n2: number): number;
+  bar(s1: string, s2: string): string;
+}
+
+function foo(c: C, x: any): string {
+  let y = x.y;
+  return c.bar(0, y); // should be able to select first case and error
+}
+
+var any_fun1 = require('./nonflowfile');
+function bar1(x: mixed) {
+  if (any_fun1(x)) {
+    (x: boolean);
+  }
+}
+
+var any_fun2 = require('./anyexportflowfile');
+function bar2(x: mixed) {
+  if (any_fun2(x)) {
+    (x: boolean);
+  }
+}

tests/any/reach.js

@@ -0,0 +1,13 @@
+/**
+ * like class and function values, any-typed values may be used in
+ * type annotations. Here we test propagation of any through the
+ * annotation - without it, the body of the if will be unreachable 
+ */
+
+type AsyncRequest = any;
+
+function foo(o: ?AsyncRequest) {
+  if (o) {
+    var n: number = o;
+  }
+}

tests/arith/Arith.js

@@ -0,0 +1,91 @@
+
+/* @providesModule Arith */
+
+function num(x:number) { }
+
+function str(x:string) { }
+
+function foo() {
+  var x = 0;
+  var y = "...";
+  var z = {};
+  num(x+x);
+  num(x+y); // error
+  str(x+y);
+  str(x+x); // error
+  str(z+y); // error
+}
+
+// test MaybeT(NumT)
+function bar0(x: ?number, y: number) {
+  num(x + y);
+}
+function bar1(x: number, y: ?number) {
+  num(x + y);
+}
+
+// test OptionalT(NumT)
+function bar2(x?: number, y: number) {
+  num(x + y);
+}
+function bar3(x: number, y?: number) {
+  num(x + y);
+}
+
+// test OptionalT(MaybeT(NumT))
+function bar4(x?: ?number, y: number) {
+  num(x + y);
+}
+function bar5(x: number, y?: ?number) {
+  num(x + y);
+}
+
+num(null + null); // === 0
+num(undefined + undefined); // === NaN
+
+num(null + 1); // === 1
+num(1 + null); // === 1
+num(undefined + 1); // === NaN
+num(1 + undefined); // === NaN
+
+num(null + true); // === 1
+num(true + null); // === 1
+num(undefined + true); // === NaN
+num(true + undefined); // === NaN
+
+str("foo" + true); // error
+str(true + "foo"); // error
+str("foo" + null); // error
+str(null + "foo"); // error
+str("foo" + undefined); // error
+str(undefined + "foo"); // error
+
+let tests = [
+  function(x: mixed, y: mixed) {
+    (x + y); // error
+    (x + 0); // error
+    (0 + x); // error
+    (x + ""); // error
+    ("" + x); // error
+    (x + {}); // error
+    ({} + x); // error
+  },
+
+  // when one side is a string or number and the other is invalid, we
+  // assume you are expecting a string or number (respectively), rather than
+  // erroring twice saying number !~> string and obj !~> string.
+  function() {
+    ((1 + {}): number); // error: object !~> number
+    (({} + 1): number); // error: object !~> number
+    (("1" + {}): string); // error: object !~> string
+    (({} + "1"): string); // error: object !~> string
+  },
+
+  function(x: any, y: number, z: string) {
+    (x + y: string); // ok
+    (y + x: string); // ok
+
+    (x + z: empty); // error, string ~> empty
+    (z + x: empty); // error, string ~> empty
+  },
+];

tests/arith/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,318 @@
+exports[`test Arith.js 1`] = `
+"
+/* @providesModule Arith */
+
+function num(x:number) { }
+
+function str(x:string) { }
+
+function foo() {
+  var x = 0;
+  var y = \"...\";
+  var z = {};
+  num(x+x);
+  num(x+y); // error
+  str(x+y);
+  str(x+x); // error
+  str(z+y); // error
+}
+
+// test MaybeT(NumT)
+function bar0(x: ?number, y: number) {
+  num(x + y);
+}
+function bar1(x: number, y: ?number) {
+  num(x + y);
+}
+
+// test OptionalT(NumT)
+function bar2(x?: number, y: number) {
+  num(x + y);
+}
+function bar3(x: number, y?: number) {
+  num(x + y);
+}
+
+// test OptionalT(MaybeT(NumT))
+function bar4(x?: ?number, y: number) {
+  num(x + y);
+}
+function bar5(x: number, y?: ?number) {
+  num(x + y);
+}
+
+num(null + null); // === 0
+num(undefined + undefined); // === NaN
+
+num(null + 1); // === 1
+num(1 + null); // === 1
+num(undefined + 1); // === NaN
+num(1 + undefined); // === NaN
+
+num(null + true); // === 1
+num(true + null); // === 1
+num(undefined + true); // === NaN
+num(true + undefined); // === NaN
+
+str(\"foo\" + true); // error
+str(true + \"foo\"); // error
+str(\"foo\" + null); // error
+str(null + \"foo\"); // error
+str(\"foo\" + undefined); // error
+str(undefined + \"foo\"); // error
+
+let tests = [
+  function(x: mixed, y: mixed) {
+    (x + y); // error
+    (x + 0); // error
+    (0 + x); // error
+    (x + \"\"); // error
+    (\"\" + x); // error
+    (x + {}); // error
+    ({} + x); // error
+  },
+
+  // when one side is a string or number and the other is invalid, we
+  // assume you are expecting a string or number (respectively), rather than
+  // erroring twice saying number !~> string and obj !~> string.
+  function() {
+    ((1 + {}): number); // error: object !~> number
+    (({} + 1): number); // error: object !~> number
+    ((\"1\" + {}): string); // error: object !~> string
+    (({} + \"1\"): string); // error: object !~> string
+  },
+
+  function(x: any, y: number, z: string) {
+    (x + y: string); // ok
+    (y + x: string); // ok
+
+    (x + z: empty); // error, string ~> empty
+    (z + x: empty); // error, string ~> empty
+  },
+];
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/* @providesModule Arith */
+function num(x: number) {
+  
+}
+function str(x: string) {
+  
+}
+function foo() {
+  var x = 0;
+  var y = \"...\";
+  var z = {};
+  num(x + x);
+  num(x + y);// error
+  str(x + y);
+  str(x + x);// error
+  str(z + y);// error
+}
+// test MaybeT(NumT)
+function bar0(x: ?number, y: number) {
+  num(x + y);
+}
+function bar1(x: number, y: ?number) {
+  num(x + y);
+}
+// test OptionalT(NumT)
+function bar2(x: number, y: number) {
+  num(x + y);
+}
+function bar3(x: number, y: number) {
+  num(x + y);
+}
+// test OptionalT(MaybeT(NumT))
+function bar4(x: ?number, y: number) {
+  num(x + y);
+}
+function bar5(x: number, y: ?number) {
+  num(x + y);
+}
+num(null + null);// === 0
+num(undefined + undefined);// === NaN
+num(null + 1);// === 1
+num(1 + null);// === 1
+num(undefined + 1);// === NaN
+num(1 + undefined);// === NaN
+num(null + true);// === 1
+num(true + null);// === 1
+num(undefined + true);// === NaN
+num(true + undefined);// === NaN
+str(\"foo\" + true);// error
+str(true + \"foo\");// error
+str(\"foo\" + null);// error
+str(null + \"foo\");// error
+str(\"foo\" + undefined);// error
+str(undefined + \"foo\");// error
+let tests = [
+  function(x: mixed, y: mixed) {
+    x + y;// error
+    x + 0;// error
+    0 + x;// error
+    x + \"\";// error
+    \"\" + x;// error
+    x + {};// error
+    ({}) + x;// error
+  },
+  // when one side is a string or number and the other is invalid, we
+  // assume you are expecting a string or number (respectively), rather than
+  // erroring twice saying number !~> string and obj !~> string.
+  function() {
+    (1 + {}: number);// error: object !~> number
+    ({} + 1: number);// error: object !~> number
+    (\"1\" + {}: string);// error: object !~> string
+    ({} + \"1\": string);// error: object !~> string
+  },
+  function(x: any, y: number, z: string) {
+    (x + y: string);// ok
+    (y + x: string);// ok
+    (x + z: empty);// error, string ~> empty
+    (z + x: empty);// error, string ~> empty
+  }
+];
+
+"
+`;
+
+exports[`test exponent.js 1`] = `
+"/* @flow */
+
+let x: number = 2 ** 3;
+x **= 4;
+
+let y: string = \"123\";
+y **= 2; // error
+
+1 + 2 ** 3 + 4;
+2 ** 2;
+(-2) ** 2;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/* @flow */
+let x: number = 2 ** 3;
+x **= 4;
+let y: string = \"123\";
+y **= 2;// error
+1 + 2 ** 3 + 4;
+2 ** 2;
+-2 ** 2;
+
+"
+`;
+
+exports[`test generic.js 1`] = `
+"/* @flow */
+
+function f<A>(a: A): A { return a + a; } // error
+function f<A,B>(a: A, b: B): A {return a + b; } // error
+function f<A,B>(a: A, b: B): A {return b + a; } // error
+function f<A,B>(a: A, b: B): B {return a + b; } // error
+function f<A,B>(a: A, b: B): B {return b + a; } // error
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:340:16)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test mult.js 1`] = `
+"/* @flow */
+
+function num(x:number) { }
+
+num(null * 1);
+num(1 * null);
+
+let x: number = 2 * 3;
+x *= 4;
+
+let y: string = \"123\";
+y *= 2; // error
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/* @flow */
+function num(x: number) {
+  
+}
+num(null * 1);
+num(1 * null);
+let x: number = 2 * 3;
+x *= 4;
+let y: string = \"123\";
+y *= 2;// error
+
+"
+`;
+
+exports[`test relational.js 1`] = `
+"/* @flow */
+
+(1 < 2);
+(1 < \"foo\"); // error
+(\"foo\" < 1); // error
+(\"foo\" < \"bar\");
+(1 < {foo: 1}); // error
+({foo: 1} < 1); // error
+({foo: 1} < {foo: 1}); // error
+(\"foo\" < {foo: 1}); // error
+({foo: 1} < \"foo\"); // error
+
+var x = (null : ?number);
+(1 < x); // 2 errors: null !~> number; undefined !~> number
+(x < 1); // 2 errors: null !~> number; undefined !~> number
+
+(null < null); // error
+(undefined < null); // error
+(null < undefined); // error
+(undefined < undefined); // error
+(NaN < 1);
+(1 < NaN);
+(NaN < NaN);
+
+let tests = [
+  function(x: any, y: number, z: string) {
+    (x > y);
+    (x > z);
+  },
+];
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/* @flow */
+1 < 2;
+1 < \"foo\";// error
+\"foo\" < 1;// error
+\"foo\" < \"bar\";
+1 < { foo: 1 };// error
+({ foo: 1 }) < 1;// error
+({ foo: 1 }) < { foo: 1 };// error
+\"foo\" < { foo: 1 };// error
+({ foo: 1 }) < \"foo\";// error
+var x = (null: ?number);
+1 < x;// 2 errors: null !~> number; undefined !~> number
+x < 1;// 2 errors: null !~> number; undefined !~> number
+null < null;// error
+undefined < null;// error
+null < undefined;// error
+undefined < undefined;// error
+NaN < 1;
+1 < NaN;
+NaN < NaN;
+let tests = [
+  function(x: any, y: number, z: string) {
+    x > y;
+    x > z;
+  }
+];
+
+"
+`;

tests/arith/exponent.js

@@ -0,0 +1,11 @@
+/* @flow */
+
+let x: number = 2 ** 3;
+x **= 4;
+
+let y: string = "123";
+y **= 2; // error
+
+1 + 2 ** 3 + 4;
+2 ** 2;
+(-2) ** 2;

tests/arith/generic.js

@@ -0,0 +1,7 @@
+/* @flow */
+
+function f<A>(a: A): A { return a + a; } // error
+function f<A,B>(a: A, b: B): A {return a + b; } // error
+function f<A,B>(a: A, b: B): A {return b + a; } // error
+function f<A,B>(a: A, b: B): B {return a + b; } // error
+function f<A,B>(a: A, b: B): B {return b + a; } // error

tests/arith/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/arith/mult.js

@@ -0,0 +1,12 @@
+/* @flow */
+
+function num(x:number) { }
+
+num(null * 1);
+num(1 * null);
+
+let x: number = 2 * 3;
+x *= 4;
+
+let y: string = "123";
+y *= 2; // error

tests/arith/relational.js

@@ -0,0 +1,30 @@
+/* @flow */
+
+(1 < 2);
+(1 < "foo"); // error
+("foo" < 1); // error
+("foo" < "bar");
+(1 < {foo: 1}); // error
+({foo: 1} < 1); // error
+({foo: 1} < {foo: 1}); // error
+("foo" < {foo: 1}); // error
+({foo: 1} < "foo"); // error
+
+var x = (null : ?number);
+(1 < x); // 2 errors: null !~> number; undefined !~> number
+(x < 1); // 2 errors: null !~> number; undefined !~> number
+
+(null < null); // error
+(undefined < null); // error
+(null < undefined); // error
+(undefined < undefined); // error
+(NaN < 1);
+(1 < NaN);
+(NaN < NaN);
+
+let tests = [
+  function(x: any, y: number, z: string) {
+    (x > y);
+    (x > z);
+  },
+];

tests/array-filter/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,63 @@
+exports[`test test.js 1`] = `
+"/* @flow */
+
+function filterOutVoids<T> (arr: Array<?T>): Array<T> {
+  return arr.filter(Boolean)
+}
+
+function filterOutSmall (arr: Array<?number>): Array<?number> {
+  return arr.filter(num => num && num > 10)
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:340:16)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test test2.js 1`] = `
+"/* @flow */
+
+function filterItems(items: Array<string|number>): Array<string|number> {
+  return items.map(item => {
+    if (typeof item === \'string\') {
+      return item.length > 2 ? item : null;
+    } else {
+      return item*10;
+    }
+  }).filter(Boolean);
+}
+
+const filteredItems = filterItems([\'foo\', \'b\', 1, 2]);
+
+console.log(filteredItems);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1530
+      return fromString(\" | \").join(path.map(print, \"types\"));
+                               ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1530:32)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.map (/src/fast-path.js:167:19)
+    at genericPrintNoParens (/src/printer.js:1497:36)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;

tests/array-filter/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/array-filter/test.js

@@ -0,0 +1,9 @@
+/* @flow */
+
+function filterOutVoids<T> (arr: Array<?T>): Array<T> {
+  return arr.filter(Boolean)
+}
+
+function filterOutSmall (arr: Array<?number>): Array<?number> {
+  return arr.filter(num => num && num > 10)
+}

tests/array-filter/test2.js

@@ -0,0 +1,15 @@
+/* @flow */
+
+function filterItems(items: Array<string|number>): Array<string|number> {
+  return items.map(item => {
+    if (typeof item === 'string') {
+      return item.length > 2 ? item : null;
+    } else {
+      return item*10;
+    }
+  }).filter(Boolean);
+}
+
+const filteredItems = filterItems(['foo', 'b', 1, 2]);
+
+console.log(filteredItems);

tests/array_spread/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,27 @@
+exports[`test test.js 1`] = `
+"var A = [1,2,3];
+var B = [...A];
+var C = [1,2,3];
+B.sort((a, b) => a - b);
+C.sort((a, b) => a - b);
+
+var x: Array<string> = [\'1\', \'2\'];
+var y: Array<string> = [\'3\', ...x];
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;

tests/array_spread/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/array_spread/test.js

@@ -0,0 +1,8 @@
+var A = [1,2,3];
+var B = [...A];
+var C = [1,2,3];
+B.sort((a, b) => a - b);
+C.sort((a, b) => a - b);
+
+var x: Array<string> = ['1', '2'];
+var y: Array<string> = ['3', ...x];

tests/arraylib/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,76 @@
+exports[`test array_lib.js 1`] = `
+"/* @flow */
+function foo(x:string) { }
+
+var a = [0];
+var b = a.map(function (x) { foo(x); return \"\" + x; });
+
+var c: number = a[0];
+var d: number = b[0];
+
+var e:Array<string> = a.reverse();
+
+var f = [\"\"];
+var g:number = f.map(function () { return 0; })[0];
+
+var h: Array<number> = [1,2,3];
+var i: Array<string> = [\'a\', \'b\', \'c\'];
+var j: Array<number | string> = h.concat(i);
+var k: Array<number> = h.concat(h);
+var l: Array<number> = h.concat(1,2,3);
+var m: Array<number | string> = h.concat(\'a\', \'b\', \'c\');
+var n: Array<number> = h.concat(\'a\', \'b\', \'c\'); // Error
+
+function reduce_test() {
+  /* Adapted from the following source:
+   * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce
+   */
+  [0, 1, 2, 3, 4].reduce(function(previousValue, currentValue, index, array) {
+    return previousValue + currentValue + array[index];
+  });
+
+  [0, 1, 2, 3, 4].reduce(function(previousValue, currentValue, index, array) {
+    return previousValue + currentValue + array[index];
+  }, 10);
+
+  var total = [0, 1, 2, 3].reduce(function(a, b) {
+    return a + b;
+  });
+
+  var flattened = [[0, 1], [2, 3], [4, 5]].reduce(function(a, b) {
+    return a.concat(b);
+  });
+
+  /* Added later, because the above is insufficient */
+
+  // acc is element type of array when no init is provided
+  [\"\"].reduce((acc, str) => acc * str.length); // error, string ~> number
+  [\"\"].reduceRight((acc, str) => acc * str.length); // error, string ~> number
+}
+
+function from_test() {
+  var a: Array<string> = Array.from([1, 2, 3], function(val, index) {
+    return index % 2 ? \"foo\" : String(val);
+  });
+  var b: Array<string> = Array.from([1, 2, 3], function(val) {
+    return String(val);
+  });
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;

tests/arraylib/array_lib.js

@@ -0,0 +1,57 @@
+/* @flow */
+function foo(x:string) { }
+
+var a = [0];
+var b = a.map(function (x) { foo(x); return "" + x; });
+
+var c: number = a[0];
+var d: number = b[0];
+
+var e:Array<string> = a.reverse();
+
+var f = [""];
+var g:number = f.map(function () { return 0; })[0];
+
+var h: Array<number> = [1,2,3];
+var i: Array<string> = ['a', 'b', 'c'];
+var j: Array<number | string> = h.concat(i);
+var k: Array<number> = h.concat(h);
+var l: Array<number> = h.concat(1,2,3);
+var m: Array<number | string> = h.concat('a', 'b', 'c');
+var n: Array<number> = h.concat('a', 'b', 'c'); // Error
+
+function reduce_test() {
+  /* Adapted from the following source:
+   * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce
+   */
+  [0, 1, 2, 3, 4].reduce(function(previousValue, currentValue, index, array) {
+    return previousValue + currentValue + array[index];
+  });
+
+  [0, 1, 2, 3, 4].reduce(function(previousValue, currentValue, index, array) {
+    return previousValue + currentValue + array[index];
+  }, 10);
+
+  var total = [0, 1, 2, 3].reduce(function(a, b) {
+    return a + b;
+  });
+
+  var flattened = [[0, 1], [2, 3], [4, 5]].reduce(function(a, b) {
+    return a.concat(b);
+  });
+
+  /* Added later, because the above is insufficient */
+
+  // acc is element type of array when no init is provided
+  [""].reduce((acc, str) => acc * str.length); // error, string ~> number
+  [""].reduceRight((acc, str) => acc * str.length); // error, string ~> number
+}
+
+function from_test() {
+  var a: Array<string> = Array.from([1, 2, 3], function(val, index) {
+    return index % 2 ? "foo" : String(val);
+  });
+  var b: Array<string> = Array.from([1, 2, 3], function(val) {
+    return String(val);
+  });
+}

tests/arraylib/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/arrays/Arrays.js

@@ -0,0 +1,39 @@
+
+/* @providesModule Arrays */
+
+function foo(x:string) { }
+
+var a = [];
+a[0] = 1;
+a[1] = "...";
+
+foo(a[1]);
+var y;
+a.forEach(x => y=x);
+
+// for literals, composite element type is union of individuals
+// note: test both tuple and non-tuple inferred literals
+var alittle: Array<?number> = [0, 1, 2, 3, null];
+var abig: Array<?number> = [0, 1, 2, 3, 4, 5, 6, 8, null];
+
+var abig2: Array<{x:number; y:number}> = [
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0, a:true},
+  {x:0, y:0, b:"hey"},
+  {x:0, y:0, c:1},
+  {x:0, y:0, c:"hey"}
+];
+
+module.exports = "arrays";

tests/arrays/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,77 @@
+exports[`test Arrays.js 1`] = `
+"
+/* @providesModule Arrays */
+
+function foo(x:string) { }
+
+var a = [];
+a[0] = 1;
+a[1] = \"...\";
+
+foo(a[1]);
+var y;
+a.forEach(x => y=x);
+
+// for literals, composite element type is union of individuals
+// note: test both tuple and non-tuple inferred literals
+var alittle: Array<?number> = [0, 1, 2, 3, null];
+var abig: Array<?number> = [0, 1, 2, 3, 4, 5, 6, 8, null];
+
+var abig2: Array<{x:number; y:number}> = [
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0},
+  {x:0, y:0, a:true},
+  {x:0, y:0, b:\"hey\"},
+  {x:0, y:0, c:1},
+  {x:0, y:0, c:\"hey\"}
+];
+
+module.exports = \"arrays\";
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test numeric_elem.js 1`] = `
+"var arr = [];
+var day = new Date;
+
+// Date instances are numeric (see Flow_js.numeric) and thus can index into
+// arrays.
+arr[day] = 0;
+(arr[day]: string); // error: number ~> string
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+var arr = [  ];
+var day = new Date();
+// Date instances are numeric (see Flow_js.numeric) and thus can index into
+// arrays.
+arr[day] = 0;
+(arr[day]: string);// error: number ~> string
+
+"
+`;

tests/arrays/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/arrays/numeric_elem.js

@@ -0,0 +1,7 @@
+var arr = [];
+var day = new Date;
+
+// Date instances are numeric (see Flow_js.numeric) and thus can index into
+// arrays.
+arr[day] = 0;
+(arr[day]: string); // error: number ~> string

tests/arrows/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,60 @@
+exports[`test advanced_arrows.js 1`] = `
+"/**
+ * @flow
+ */
+
+var add = (x: number, y: number): number => x + y;
+
+var bad = (x: number): string => x; // Error!
+
+var ident = <T>(x: T): T => x;
+(ident(1): number);
+(ident(\"hi\"): number); // Error
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:367:25)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test arrows.js 1`] = `
+"function selectBestEffortImageForWidth(
+    maxWidth: number,
+    images: Array<Image>
+): Image {
+    var maxPixelWidth = maxWidth;
+    //images = images.sort(function (a, b) { return a.width - b.width });
+    images = images.sort((a, b) => (a.width - b.width) + \"\");
+    return images.find(image => image.width >= maxPixelWidth) ||
+        images[images.length - 1];
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;

tests/arrows/advanced_arrows.js

@@ -0,0 +1,11 @@
+/**
+ * @flow
+ */
+
+var add = (x: number, y: number): number => x + y;
+
+var bad = (x: number): string => x; // Error!
+
+var ident = <T>(x: T): T => x;
+(ident(1): number);
+(ident("hi"): number); // Error

tests/arrows/arrows.js

@@ -0,0 +1,10 @@
+function selectBestEffortImageForWidth(
+    maxWidth: number,
+    images: Array<Image>
+): Image {
+    var maxPixelWidth = maxWidth;
+    //images = images.sort(function (a, b) { return a.width - b.width });
+    images = images.sort((a, b) => (a.width - b.width) + "");
+    return images.find(image => image.width >= maxPixelWidth) ||
+        images[images.length - 1];
+}

tests/arrows/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/ast_tokens/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,34 @@
+exports[`test foo.js 1`] = `
+"// Regex literals require a lexer mode change
+/asdf/g;
+
+// JSX also requires a lexer mode change
+<div attr1=\'42\' attr2={\'asdf\'} >asdf</div>;
+
+// Async arrow functions require backtracking
+var a = async () => 42;
+
+// Type annotations have a special lex mode
+var a: number = 42;
+
+// Token stream should continue even with parse errors
+var var
+a;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (14:4)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$2.parseBindingAtom (/node_modules/babylon/lib/index.js:2929:12)
+    at Parser.pp$1.parseVarHead (/node_modules/babylon/lib/index.js:2226:18)
+    at Parser.parseVarHead (/node_modules/babylon/lib/index.js:5611:13)
+    at Parser.pp$1.parseVar (/node_modules/babylon/lib/index.js:2209:10)
+    at Parser.pp$1.parseVarStatement (/node_modules/babylon/lib/index.js:2042:8)
+    at Parser.pp$1.parseStatement (/node_modules/babylon/lib/index.js:1735:19)
+    at Parser.parseStatement (/node_modules/babylon/lib/index.js:5224:22)
+    at Parser.pp$1.parseBlockBody (/node_modules/babylon/lib/index.js:2139:21)
+"
+`;

tests/ast_tokens/foo.js

@@ -0,0 +1,15 @@
+// Regex literals require a lexer mode change
+/asdf/g;
+
+// JSX also requires a lexer mode change
+<div attr1='42' attr2={'asdf'} >asdf</div>;
+
+// Async arrow functions require backtracking
+var a = async () => 42;
+
+// Type annotations have a special lex mode
+var a: number = 42;
+
+// Token stream should continue even with parse errors
+var var
+a;

tests/ast_tokens/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/async/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,471 @@
+exports[`test async.js 1`] = `
+"// @flow
+
+// \"For async functions, a Promise<T> is returned,
+// and the type of return expressions must be T.\"
+//
+
+async function f0(): Promise<number> {
+  return 1;
+}
+
+async function f1(): Promise<bool> {
+  return 1;  // error, number != bool
+}
+
+// await: (p: Promise<T> | T) => T
+//
+
+async function f2(p: Promise<number>): Promise<number> {
+  var x: number = await p;
+  var y: number = await 1;
+  return x + y;
+}
+
+async function f3(p: Promise<number>): Promise<number> {
+  return await p;
+}
+
+// TODO: this is one of those bad generic errors, currently:
+// \"inconsistent use of library definitions\" with two core.js locs
+async function f4(p: Promise<number>): Promise<bool> {
+  return await p; // error, number != bool
+}
+
+// async arrow functions
+//
+
+var f5: () => Promise<number> = async () => await 1;
+
+// async methods
+//
+
+class C {
+  async m() { return 1; }
+  async mt<T>(a: T): Promise<T> { return a; }
+  static async m(a): void { await a; } // error, void != Promise<void>
+  static async mt<T>(a: T): Promise<T> { return a; }
+}
+
+// async function props
+
+var obj = { f: async () => await 1 };
+var objf : () => Promise<number> = obj.f;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test async_base_class.js 1`] = `
+"// This is kind of weird, but it should parse. This works in babel without the
+// parens around (await promise). From the es6 and async/await specs I (nmote)
+// am not clear on whether it should. In any case it\'s a strange corner case
+// that is probably not important to support.
+class C {};
+
+var P: Promise<Class<C>> = new Promise(function (resolve, reject) {
+  resolve(C);
+});
+
+async function foo() {
+  class Bar extends (await P) { }
+  return Bar;
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test async_parse.js 1`] = `
+"async function f() {}
+async function ft<T>(a: T) {}
+
+class C {
+  async m() {}
+  async mt<T>(a: T) {}
+  static async m(a) {}
+  static async mt<T>(a: T) {}
+}
+
+var e = async function () {};
+var et = async function<T> (a: T) {};
+
+var n = new async function() {};
+
+var o = { async m() {} };
+var ot = { async m<T>(a: T) {} };
+var oz = { async async() {} };
+
+var x = { async : 5 };
+console.log(x.async);
+
+var async = 3;
+var y = { async };
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:340:16)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test async_promise.js 1`] = `
+"async function f(): Promise<number> {
+  return Promise.resolve(1);
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test async_return_void.js 1`] = `
+"// @flow
+
+async function foo1(): Promise<string> {
+  return;
+}
+
+async function foo2(): Promise<string> {
+  return undefined;
+}
+
+async function foo3(): Promise<string> {
+  function bar() { }
+  return bar();
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test async2.js 1`] = `
+"// @flow
+
+// misc basic
+
+function test1() {
+  async function foo() {
+    return 42;
+  }
+
+  async function bar() {
+    var a = await foo();
+    var b: number = a; // valid
+    var c: string = a; // Error: number ~> string
+  }
+}
+
+//
+// void returns:
+//
+
+// inference should produce return type Promise<void>
+// in the absence of an explicit return
+//
+
+function test2() {
+  async function voidoid1() {
+    console.log(\"HEY\");
+  }
+
+  var voidoid2: () => Promise<void> = voidoid1; // ok
+
+  var voidoid3: () => void = voidoid1; // error, void != Promise<void>
+}
+
+// annotated return type of Promise<void> should work
+//
+
+function test3() {
+  async function voidoid4(): Promise<void> { // ok
+    console.log(\"HEY\");
+  }
+}
+
+// other annotated return types should fail
+// (note: misannotated return types with explicit
+// return statements are covered in async.js)
+//
+
+function test4() {
+  async function voidoid5(): void { // error, void != Promise<void>
+    console.log(\"HEY\");
+  }
+}
+
+function test5() {
+  async function voidoid6()
+  : Promise<number> { // error, number != void
+    console.log(\"HEY\");
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1348
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1348:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1254:25)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test async3.js 1`] = `
+"// @flow
+
+/**
+ * test nested-promise unwrapping.
+ * Note: currently we don\'t do this properly in the underlying
+ * type of the Promise class, which causes spurious errors to
+ * be raised here. Once that\'s fixed, the errors here will go
+ * away.
+ */
+
+async function foo() {
+  return 42;
+}
+
+async function bar() {
+  return foo();
+}
+
+async function baz() {
+
+  // a should now be typed as number, but is in fact
+  // Promise<number> until nested-promise unwrap is fixed
+  var a = await bar();
+
+  // TODO this is valid code, but currently gives Promise ~> number error
+  // due to lack of transitive Promise unwrap.
+  var b: number = a;
+
+  // should be number ~> string error, but currently gives
+  // Promise ~> string error for the same reason
+  var c: string = a;
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// @flow
+/**
+ * test nested-promise unwrapping.
+ * Note: currently we don\'t do this properly in the underlying
+ * type of the Promise class, which causes spurious errors to
+ * be raised here. Once that\'s fixed, the errors here will go
+ * away.
+ */
+async function foo() {
+  return 42;
+}
+async function bar() {
+  return foo();
+}
+async function baz() {
+  // a should now be typed as number, but is in fact
+  // Promise<number> until nested-promise unwrap is fixed
+  var a = await bar();
+  // TODO this is valid code, but currently gives Promise ~> number error
+  // due to lack of transitive Promise unwrap.
+  var b: number = a;
+  // should be number ~> string error, but currently gives
+  // Promise ~> string error for the same reason
+  var c: string = a;
+}
+
+"
+`;
+
+exports[`test await_not_in_async.js 1`] = `
+"// note: currently, await-within-async enforcement is a
+// done by the parser, which bails after a single error.
+
+function f() {
+  await 1;
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: await is a reserved word (5:2)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp$3.checkReservedWord (/node_modules/babylon/lib/index.js:4143:10)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4121:12)
+    at Parser.pp$3.parseExprAtom (/node_modules/babylon/lib/index.js:3490:21)
+    at Parser.parseExprAtom (/node_modules/babylon/lib/index.js:6408:22)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3337:19)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+"
+`;
+
+exports[`test await_not_in_async2.js 1`] = `
+"// note: currently, await-within-async enforcement is a
+// done by the parser, which bails after a single error.
+
+function f(x) { return x; }
+
+f(await 1);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: await is a reserved word (6:2)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp$3.checkReservedWord (/node_modules/babylon/lib/index.js:4143:10)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4121:12)
+    at Parser.pp$3.parseExprAtom (/node_modules/babylon/lib/index.js:3490:21)
+    at Parser.parseExprAtom (/node_modules/babylon/lib/index.js:6408:22)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3337:19)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+"
+`;
+
+exports[`test await_not_in_async3.js 1`] = `
+"// note: currently, await-within-async enforcement is a
+// done by the parser, which bails after a single error.
+
+async function f(x) { return x; }
+
+f(await 1);
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: await is a reserved word (6:2)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp$3.checkReservedWord (/node_modules/babylon/lib/index.js:4143:10)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4121:12)
+    at Parser.pp$3.parseExprAtom (/node_modules/babylon/lib/index.js:3490:21)
+    at Parser.parseExprAtom (/node_modules/babylon/lib/index.js:6408:22)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3337:19)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+"
+`;
+
+exports[`test await_parse.js 1`] = `
+"async function f() { await 1; }
+async function ft<T>(a: T) { await 1; }
+
+class C {
+  async m() { await 1; }
+  async mt<T>(a: T) { await 1; }
+  static async m(a) { await 1; }
+  static async mt<T>(a: T) { await 1; }
+}
+
+var e = async function () { await 1; };
+var et = async function<T> (a: T) { await 1; };
+
+var n = new async function() { await 1; };
+
+var o = { async m() { await 1; } };
+var ot = { async m<T>(a: T) { await 1; } };
+var oz = { async async(async) { await async; } };
+
+var x = { await : 5 };
+console.log(x.await);
+
+var await = 3;
+var y = { await };
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: await is a reserved word (23:4)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp$3.checkReservedWord (/node_modules/babylon/lib/index.js:4143:10)
+    at Parser.pp$2.checkLVal (/node_modules/babylon/lib/index.js:2990:12)
+    at Parser.checkLVal (/node_modules/babylon/lib/index.js:5446:22)
+    at Parser.pp$1.parseVarHead (/node_modules/babylon/lib/index.js:2227:8)
+    at Parser.parseVarHead (/node_modules/babylon/lib/index.js:5611:13)
+    at Parser.pp$1.parseVar (/node_modules/babylon/lib/index.js:2209:10)
+    at Parser.pp$1.parseVarStatement (/node_modules/babylon/lib/index.js:2042:8)
+    at Parser.pp$1.parseStatement (/node_modules/babylon/lib/index.js:1735:19)
+    at Parser.parseStatement (/node_modules/babylon/lib/index.js:5224:22)
+"
+`;

tests/async/async.js

@@ -0,0 +1,52 @@
+// @flow
+
+// "For async functions, a Promise<T> is returned,
+// and the type of return expressions must be T."
+//
+
+async function f0(): Promise<number> {
+  return 1;
+}
+
+async function f1(): Promise<bool> {
+  return 1;  // error, number != bool
+}
+
+// await: (p: Promise<T> | T) => T
+//
+
+async function f2(p: Promise<number>): Promise<number> {
+  var x: number = await p;
+  var y: number = await 1;
+  return x + y;
+}
+
+async function f3(p: Promise<number>): Promise<number> {
+  return await p;
+}
+
+// TODO: this is one of those bad generic errors, currently:
+// "inconsistent use of library definitions" with two core.js locs
+async function f4(p: Promise<number>): Promise<bool> {
+  return await p; // error, number != bool
+}
+
+// async arrow functions
+//
+
+var f5: () => Promise<number> = async () => await 1;
+
+// async methods
+//
+
+class C {
+  async m() { return 1; }
+  async mt<T>(a: T): Promise<T> { return a; }
+  static async m(a): void { await a; } // error, void != Promise<void>
+  static async mt<T>(a: T): Promise<T> { return a; }
+}
+
+// async function props
+
+var obj = { f: async () => await 1 };
+var objf : () => Promise<number> = obj.f;

tests/async/async2.js

@@ -0,0 +1,60 @@
+// @flow
+
+// misc basic
+
+function test1() {
+  async function foo() {
+    return 42;
+  }
+
+  async function bar() {
+    var a = await foo();
+    var b: number = a; // valid
+    var c: string = a; // Error: number ~> string
+  }
+}
+
+//
+// void returns:
+//
+
+// inference should produce return type Promise<void>
+// in the absence of an explicit return
+//
+
+function test2() {
+  async function voidoid1() {
+    console.log("HEY");
+  }
+
+  var voidoid2: () => Promise<void> = voidoid1; // ok
+
+  var voidoid3: () => void = voidoid1; // error, void != Promise<void>
+}
+
+// annotated return type of Promise<void> should work
+//
+
+function test3() {
+  async function voidoid4(): Promise<void> { // ok
+    console.log("HEY");
+  }
+}
+
+// other annotated return types should fail
+// (note: misannotated return types with explicit
+// return statements are covered in async.js)
+//
+
+function test4() {
+  async function voidoid5(): void { // error, void != Promise<void>
+    console.log("HEY");
+  }
+}
+
+function test5() {
+  async function voidoid6()
+  : Promise<number> { // error, number != void
+    console.log("HEY");
+  }
+}

tests/async/async3.js

@@ -0,0 +1,32 @@
+// @flow
+
+/**
+ * test nested-promise unwrapping.
+ * Note: currently we don't do this properly in the underlying
+ * type of the Promise class, which causes spurious errors to
+ * be raised here. Once that's fixed, the errors here will go
+ * away.
+ */
+
+async function foo() {
+  return 42;
+}
+
+async function bar() {
+  return foo();
+}
+
+async function baz() {
+
+  // a should now be typed as number, but is in fact
+  // Promise<number> until nested-promise unwrap is fixed
+  var a = await bar();
+
+  // TODO this is valid code, but currently gives Promise ~> number error
+  // due to lack of transitive Promise unwrap.
+  var b: number = a;
+
+  // should be number ~> string error, but currently gives
+  // Promise ~> string error for the same reason
+  var c: string = a;
+}

tests/async/async_base_class.js

@@ -0,0 +1,14 @@
+// This is kind of weird, but it should parse. This works in babel without the
+// parens around (await promise). From the es6 and async/await specs I (nmote)
+// am not clear on whether it should. In any case it's a strange corner case
+// that is probably not important to support.
+class C {};
+
+var P: Promise<Class<C>> = new Promise(function (resolve, reject) {
+  resolve(C);
+});
+
+async function foo() {
+  class Bar extends (await P) { }
+  return Bar;
+}

tests/async/async_parse.js

@@ -0,0 +1,24 @@
+async function f() {}
+async function ft<T>(a: T) {}
+
+class C {
+  async m() {}
+  async mt<T>(a: T) {}
+  static async m(a) {}
+  static async mt<T>(a: T) {}
+}
+
+var e = async function () {};
+var et = async function<T> (a: T) {};
+
+var n = new async function() {};
+
+var o = { async m() {} };
+var ot = { async m<T>(a: T) {} };
+var oz = { async async() {} };
+
+var x = { async : 5 };
+console.log(x.async);
+
+var async = 3;
+var y = { async };

tests/async/async_promise.js

@@ -0,0 +1,3 @@
+async function f(): Promise<number> {
+  return Promise.resolve(1);
+}

tests/async/async_return_void.js

@@ -0,0 +1,14 @@
+// @flow
+
+async function foo1(): Promise<string> {
+  return;
+}
+
+async function foo2(): Promise<string> {
+  return undefined;
+}
+
+async function foo3(): Promise<string> {
+  function bar() { }
+  return bar();
+}

tests/async/await_not_in_async.js

@@ -0,0 +1,6 @@
+// note: currently, await-within-async enforcement is a
+// done by the parser, which bails after a single error.
+
+function f() {
+  await 1;
+}

tests/async/await_not_in_async2.js

@@ -0,0 +1,6 @@
+// note: currently, await-within-async enforcement is a
+// done by the parser, which bails after a single error.
+
+function f(x) { return x; }
+
+f(await 1);

tests/async/await_not_in_async3.js

@@ -0,0 +1,6 @@
+// note: currently, await-within-async enforcement is a
+// done by the parser, which bails after a single error.
+
+async function f(x) { return x; }
+
+f(await 1);

tests/async/await_parse.js

@@ -0,0 +1,24 @@
+async function f() { await 1; }
+async function ft<T>(a: T) { await 1; }
+
+class C {
+  async m() { await 1; }
+  async mt<T>(a: T) { await 1; }
+  static async m(a) { await 1; }
+  static async mt<T>(a: T) { await 1; }
+}
+
+var e = async function () { await 1; };
+var et = async function<T> (a: T) { await 1; };
+
+var n = new async function() { await 1; };
+
+var o = { async m() { await 1; } };
+var ot = { async m<T>(a: T) { await 1; } };
+var oz = { async async(async) { await async; } };
+
+var x = { await : 5 };
+console.log(x.await);
+
+var await = 3;
+var y = { await };

tests/async/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/async_iteration/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,213 @@
+exports[`test delegate_yield.js 1`] = `
+"async function *delegate_next() {
+  async function *inner() {
+    var x: void = yield; // error: number ~> void
+  }
+  yield *inner();
+}
+delegate_next().next(0);
+
+async function *delegate_yield() {
+  async function *inner() {
+    yield 0;
+  }
+  yield *inner();
+}
+(async () => {
+  for await (const x of delegate_yield()) {
+    (x: void); // error: number ~> void
+  }
+});
+
+async function *delegate_return() {
+  async function *inner() {
+    return 0;
+  }
+  var x: void = yield *inner(); // error: number ~> void
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+async function* delegate_next() {
+  async function* inner() {
+    var x: void = yield;// error: number ~> void
+  }
+  yield* inner();
+}
+delegate_next().next(0);
+async function* delegate_yield() {
+  async function* inner() {
+    yield 0;
+  }
+  yield* inner();
+}
+async () => {
+  for await (const x of delegate_yield()) {
+    (x: void);// error: number ~> void
+  }
+};
+async function* delegate_return() {
+  async function* inner() {
+    return 0;
+  }
+  var x: void = yield* inner();// error: number ~> void
+}
+
+"
+`;
+
+exports[`test generator.js 1`] = `
+"declare interface File {
+  readLine(): Promise<string>;
+  close(): void;
+  EOF: boolean;
+}
+
+declare function fileOpen(path: string): Promise<File>;
+
+async function* readLines(path) {
+  let file: File = await fileOpen(path);
+
+  try {
+    while (!file.EOF) {
+      yield await file.readLine();
+    }
+  } finally {
+    file.close();
+  }
+}
+
+async function f() {
+  for await (const line of readLines(\"/path/to/file\")) {
+    (line: void); // error: string ~> void
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1391
+          fromString(\", \").join(path.map(print, \"extends\"))
+                           ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1391:28)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at /src/printer.js:1601:18
+    at FastPath.map (/src/fast-path.js:167:19)
+    at printStatementSequence (/src/printer.js:1586:8)
+    at /src/printer.js:238:16
+    at FastPath.call (/src/fast-path.js:113:16)
+"
+`;
+
+exports[`test return.js 1`] = `
+"declare var gen: AsyncGenerator<void,string,void>;
+
+// You can pass whatever you like to return, it doesn\'t need to be related to
+// the AsyncGenerator\'s return type
+gen.return(0).then(result => {
+  (result.value: void); // error: string | number ~> void
+});
+
+// However, a generator can \"refuse\" the return by catching an exception and
+// yielding or returning internally.
+async function *refuse_return() {
+  try {
+    yield 1;
+  } finally {
+    return 0;
+  }
+}
+refuse_return().return(\"string\").then(result => {
+  if (result.done) {
+    (result.value: string); // error: number | void ~> string
+  }
+});
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/src/printer.js:1497
+        fromString(\", \").join(path.map(print, \"params\")),
+                         ^
+
+TypeError: fromString(...).join is not a function
+    at genericPrintNoParens (/src/printer.js:1497:26)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+    at printGenerically (/src/printer.js:111:12)
+    at FastPath.call (/src/fast-path.js:113:16)
+    at genericPrintNoParens (/src/printer.js:1374:14)
+    at genericPrint (/src/printer.js:166:7)
+    at p (/src/printer.js:111:37)
+    at exports.printComments (/src/comments.js:327:20)
+"
+`;
+
+exports[`test throw.js 1`] = `
+"async function *catch_return() {
+  try {
+    yield 0;
+  } catch (e) {
+    return e;
+  }
+}
+
+(async () => {
+  catch_return().throw(\"\").then(({value}) => {
+    if (value !== undefined) {
+      (value: void); // error: number ~> void
+    }
+  });
+});
+
+async function *yield_return() {
+  try {
+    yield 0;
+    return;
+  } catch (e) {
+    yield e;
+  }
+}
+
+(async () => {
+  yield_return().throw(\"\").then(({value}) => {
+    if (value !== undefined) {
+      (value: void); // error: number ~> void
+    }
+  });
+});
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+async function* catch_return() {
+  try {
+    yield 0;
+  } catch (e) {
+    return e;
+  }
+}
+async () => {
+  catch_return().throw(\"\").then(
+    ({ value }) => {
+      if (value !== undefined) {
+        (value: void);// error: number ~> void
+      }
+    }
+  );
+};
+async function* yield_return() {
+  try {
+    yield 0;
+    return;
+  } catch (e) {
+    yield e;
+  }
+}
+async () => {
+  yield_return().throw(\"\").then(
+    ({ value }) => {
+      if (value !== undefined) {
+        (value: void);// error: number ~> void
+      }
+    }
+  );
+};
+
+"
+`;

tests/async_iteration/delegate_yield.js

@@ -0,0 +1,26 @@
+async function *delegate_next() {
+  async function *inner() {
+    var x: void = yield; // error: number ~> void
+  }
+  yield *inner();
+}
+delegate_next().next(0);
+
+async function *delegate_yield() {
+  async function *inner() {
+    yield 0;
+  }
+  yield *inner();
+}
+(async () => {
+  for await (const x of delegate_yield()) {
+    (x: void); // error: number ~> void
+  }
+});
+
+async function *delegate_return() {
+  async function *inner() {
+    return 0;
+  }
+  var x: void = yield *inner(); // error: number ~> void
+}

tests/async_iteration/generator.js

@@ -0,0 +1,25 @@
+declare interface File {
+  readLine(): Promise<string>;
+  close(): void;
+  EOF: boolean;
+}
+
+declare function fileOpen(path: string): Promise<File>;
+
+async function* readLines(path) {
+  let file: File = await fileOpen(path);
+
+  try {
+    while (!file.EOF) {
+      yield await file.readLine();
+    }
+  } finally {
+    file.close();
+  }
+}
+
+async function f() {
+  for await (const line of readLines("/path/to/file")) {
+    (line: void); // error: string ~> void
+  }
+}

tests/async_iteration/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/async_iteration/return.js

@@ -0,0 +1,22 @@
+declare var gen: AsyncGenerator<void,string,void>;
+
+// You can pass whatever you like to return, it doesn't need to be related to
+// the AsyncGenerator's return type
+gen.return(0).then(result => {
+  (result.value: void); // error: string | number ~> void
+});
+
+// However, a generator can "refuse" the return by catching an exception and
+// yielding or returning internally.
+async function *refuse_return() {
+  try {
+    yield 1;
+  } finally {
+    return 0;
+  }
+}
+refuse_return().return("string").then(result => {
+  if (result.done) {
+    (result.value: string); // error: number | void ~> string
+  }
+});

tests/async_iteration/throw.js

@@ -0,0 +1,32 @@
+async function *catch_return() {
+  try {
+    yield 0;
+  } catch (e) {
+    return e;
+  }
+}
+
+(async () => {
+  catch_return().throw("").then(({value}) => {
+    if (value !== undefined) {
+      (value: void); // error: number ~> void
+    }
+  });
+});
+
+async function *yield_return() {
+  try {
+    yield 0;
+    return;
+  } catch (e) {
+    yield e;
+  }
+}
+
+(async () => {
+  yield_return().throw("").then(({value}) => {
+    if (value !== undefined) {
+      (value: void); // error: number ~> void
+    }
+  });
+});

tests/autocomplete/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,582 @@
+exports[`test bar.js 1`] = `
+"// @flow
+
+var o = require(\'./unknown\');
+o.x.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (5:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test bool.js 1`] = `
+"// @flow
+
+true.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (4:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test customfun.js 1`] = `
+"// @flow
+
+declare var idx: $Facebookism$Idx;
+declare var merge: $Facebookism$Merge;
+declare var mergeDeepInto: $Facebookism$MergeDeepInto;
+declare var mergeInto: $Facebookism$MergeInto;
+declare var mixin: $Facebookism$Mixin;
+declare var objectGetPrototypeOf: Object$GetPrototypeOf
+declare var objectAssign: Object$Assign
+
+m
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// @flow
+declare var idx: $Facebookism$Idx;
+declare var merge: $Facebookism$Merge;
+declare var mergeDeepInto: $Facebookism$MergeDeepInto;
+declare var mergeInto: $Facebookism$MergeInto;
+declare var mixin: $Facebookism$Mixin;
+declare var objectGetPrototypeOf: Object$GetPrototypeOf;
+declare var objectAssign: Object$Assign;
+m;
+
+"
+`;
+
+exports[`test foo.js 1`] = `
+"/**
+ * @flow
+ */
+
+var obj = {
+  num: 123,
+  str: \'hello\',
+};
+
+obj.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (11:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test foo_parse_fail.js 1`] = `
+"/**
+ * @flow
+ */
+
+var obj = {
+  num: 123,
+  str: \'hello\',
+};
+
+console.log(obj.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (11:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test fun.js 1`] = `
+"/* @flow */
+
+function foo(f: () => number) {
+  f.
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (5:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test function_builtins.js 1`] = `
+"/* @flow */
+
+function foo(f: Function) {
+  f.
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (5:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test generics.js 1`] = `
+"// @flow
+
+class C<X> { }
+
+function foo(o: { cn: C<number> }) {
+  o.
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (7:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test if.js 1`] = `
+"// @flow
+const x = \'\';
+if (x.)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (3:6)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test issue-1368.js 1`] = `
+"/* @flow */
+class Test {
+  prop: number;
+
+  constructor(prop: number) {
+    this.prop = prop;
+  }
+}
+
+class ExtendTest extends Test {
+  extended: string;
+
+  constructor(extended: string) {
+    super(10);
+    this.extended = extended;
+  }
+
+  method() {
+    this.prop = 12;
+    this./* here */
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (21:2)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test jsx1.js 1`] = `
+"// @flow
+
+var React = require(\'react\');
+
+class C extends React.Component {
+  props: { x: number };
+}
+<C 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:5687
+          throw jsxError || err;
+          ^
+
+SyntaxError: Unexpected token (9:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$8.jsxParseIdentifier (/node_modules/babylon/lib/index.js:6199:10)
+    at Parser.pp$8.jsxParseNamespacedName (/node_modules/babylon/lib/index.js:6210:19)
+    at Parser.pp$8.jsxParseAttribute (/node_modules/babylon/lib/index.js:6305:20)
+    at Parser.pp$8.jsxParseOpeningElementAt (/node_modules/babylon/lib/index.js:6317:31)
+    at Parser.pp$8.jsxParseElementAt (/node_modules/babylon/lib/index.js:6339:29)
+    at Parser.pp$8.jsxParseElement (/node_modules/babylon/lib/index.js:6394:15)
+    at Parser.parseExprAtom (/node_modules/babylon/lib/index.js:6406:21)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3337:19)
+"
+`;
+
+exports[`test jsx2.js 1`] = `
+"// @flow
+
+var React = require(\'react\');
+
+class C extends React.Component {
+  props: { x: number, y: string };
+}
+<C x = 0, 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:5687
+          throw jsxError || err;
+          ^
+
+SyntaxError: JSX value should be either an expression or a quoted JSX text (8:7)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp$8.jsxParseAttributeValue (/node_modules/babylon/lib/index.js:6255:12)
+    at Parser.pp$8.jsxParseAttribute (/node_modules/babylon/lib/index.js:6306:42)
+    at Parser.pp$8.jsxParseOpeningElementAt (/node_modules/babylon/lib/index.js:6317:31)
+    at Parser.pp$8.jsxParseElementAt (/node_modules/babylon/lib/index.js:6339:29)
+    at Parser.pp$8.jsxParseElement (/node_modules/babylon/lib/index.js:6394:15)
+    at Parser.parseExprAtom (/node_modules/babylon/lib/index.js:6406:21)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3337:19)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+"
+`;
+
+exports[`test num.js 1`] = `
+"// @flow
+
+var num = 123;
+num.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (5:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test object_builtins.js 1`] = `
+"/* @flow */
+
+function foo(o: Object) {
+  o.
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (5:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test optional.js 1`] = `
+"// @flow
+
+function foo(obj: { x?: string, f: (x?: string) => void, o: { x?: string } }) {
+  return obj.
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (5:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test override.js 1`] = `
+"// @flow
+
+class C {
+  override(): number | string { return 0; }
+}
+
+class D extends C {
+  foo() { return this.override() }
+  override(): string { return \"\"; }
+  bar() { this.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (11:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test qux.js 1`] = `
+"// @flow
+
+class C { x: number; }
+
+var c: C = new C;
+c.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (7:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test str.js 1`] = `
+"// @flow
+
+\"hello\".
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (4:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test this.js 1`] = `
+"/* @flow */
+
+// issue #1197
+class Foo {
+  baz: string;
+  bar() {}
+  hello() {
+    this.
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (9:2)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test typeparams.js 1`] = `
+"// @flow
+
+class Bounds<N: number, F: () => N> {
+  foo: F;
+  bar() {
+    this.foo().
+  }
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (7:2)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test union.js 1`] = `
+"/* @flow */
+
+function foo(a: boolean, x: { bar: string }, y: Object) {
+  var z;
+  if (a) {
+    z = x;
+  } else {
+    z = y;
+  }
+  z.
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/node_modules/babylon/lib/index.js:4255
+  throw err;
+  ^
+
+SyntaxError: Unexpected token (11:0)
+    at Parser.pp$5.raise (/node_modules/babylon/lib/index.js:4252:13)
+    at Parser.pp.unexpected (/node_modules/babylon/lib/index.js:1633:8)
+    at Parser.pp$3.parseIdentifier (/node_modules/babylon/lib/index.js:4128:10)
+    at Parser.pp$3.parseSubscripts (/node_modules/babylon/lib/index.js:3360:30)
+    at Parser.pp$3.parseExprSubscripts (/node_modules/babylon/lib/index.js:3347:15)
+    at Parser.pp$3.parseMaybeUnary (/node_modules/babylon/lib/index.js:3317:19)
+    at Parser.pp$3.parseExprOps (/node_modules/babylon/lib/index.js:3247:19)
+    at Parser.pp$3.parseMaybeConditional (/node_modules/babylon/lib/index.js:3224:19)
+    at Parser.pp$3.parseMaybeAssign (/node_modules/babylon/lib/index.js:3187:19)
+    at Parser.parseMaybeAssign (/node_modules/babylon/lib/index.js:5700:20)
+"
+`;
+
+exports[`test unknown.js 1`] = `
+"// @noflow
+module.exports = { x: { y: \"\" } };
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// @noflow
+module.exports = { x: { y: \"\" } };
+
+"
+`;

tests/autocomplete/bar.js

@@ -0,0 +1,4 @@
+// @flow
+
+var o = require('./unknown');
+o.x.

tests/autocomplete/bool.js

@@ -0,0 +1,3 @@
+// @flow
+
+true.

tests/autocomplete/customfun.js

@@ -0,0 +1,11 @@
+// @flow
+
+declare var idx: $Facebookism$Idx;
+declare var merge: $Facebookism$Merge;
+declare var mergeDeepInto: $Facebookism$MergeDeepInto;
+declare var mergeInto: $Facebookism$MergeInto;
+declare var mixin: $Facebookism$Mixin;
+declare var objectGetPrototypeOf: Object$GetPrototypeOf
+declare var objectAssign: Object$Assign
+
+m

tests/autocomplete/foo.js

@@ -0,0 +1,10 @@
+/**
+ * @flow
+ */
+
+var obj = {
+  num: 123,
+  str: 'hello',
+};
+
+obj.

tests/autocomplete/foo_parse_fail.js

@@ -0,0 +1,10 @@
+/**
+ * @flow
+ */
+
+var obj = {
+  num: 123,
+  str: 'hello',
+};
+
+console.log(obj.

tests/autocomplete/fun.js

@@ -0,0 +1,5 @@
+/* @flow */
+
+function foo(f: () => number) {
+  f.
+}

tests/autocomplete/function_builtins.js

@@ -0,0 +1,5 @@
+/* @flow */
+
+function foo(f: Function) {
+  f.
+}

tests/autocomplete/generics.js

@@ -0,0 +1,7 @@
+// @flow
+
+class C<X> { }
+
+function foo(o: { cn: C<number> }) {
+  o.
+}

tests/autocomplete/if.js

@@ -0,0 +1,3 @@
+// @flow
+const x = '';
+if (x.)

tests/autocomplete/issue-1368.js

@@ -0,0 +1,22 @@
+/* @flow */
+class Test {
+  prop: number;
+
+  constructor(prop: number) {
+    this.prop = prop;
+  }
+}
+
+class ExtendTest extends Test {
+  extended: string;
+
+  constructor(extended: string) {
+    super(10);
+    this.extended = extended;
+  }
+
+  method() {
+    this.prop = 12;
+    this./* here */
+  }
+}

tests/autocomplete/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname);

tests/autocomplete/jsx1.js

@@ -0,0 +1,8 @@
+// @flow
+
+var React = require('react');
+
+class C extends React.Component {
+  props: { x: number };
+}
+<C 

tests/autocomplete/jsx2.js

@@ -0,0 +1,8 @@
+// @flow
+
+var React = require('react');
+
+class C extends React.Component {
+  props: { x: number, y: string };
+}
+<C x = 0, 

tests/autocomplete/num.js

@@ -0,0 +1,4 @@
+// @flow
+
+var num = 123;
+num.

tests/autocomplete/object_builtins.js

@@ -0,0 +1,5 @@
+/* @flow */
+
+function foo(o: Object) {
+  o.
+}

tests/autocomplete/optional.js

@@ -0,0 +1,5 @@
+// @flow
+
+function foo(obj: { x?: string, f: (x?: string) => void, o: { x?: string } }) {
+  return obj.
+}