Fix empty line with flow union (#1511)

src/printer.js

@@ -748,9 +748,9 @@ function genericPrintNoParens(path, options, print, args) {
     case "TSInterfaceDeclaration":
     case "TSTypeLiteral": {
       var isTypeAnnotation = n.type === "ObjectTypeAnnotation";
-      var isTypeScriptTypeAnnotaion = n.type === "TSTypeLiteral";
+      var isTypeScriptTypeAnnotation = n.type === "TSTypeLiteral";
       var isTypeScriptInterfaceDeclaration = n.type === "TSInterfaceDeclaration";
-      var isTypeScriptType = isTypeScriptTypeAnnotaion || isTypeScriptInterfaceDeclaration;
+      var isTypeScriptType = isTypeScriptTypeAnnotation || isTypeScriptInterfaceDeclaration;
       // Leave this here because we *might* want to make this
       // configurable later -- flow accepts ";" for type separators,
       // typescript accepts ";" and newlines
@@ -1903,8 +1903,11 @@ function genericPrintNoParens(path, options, print, args) {
 
       const parent = path.getParentNode();
       // If there's a leading comment, the parent is doing the indentation
-      const shouldIndent = !(parent.type === "TypeAlias" &&
-        hasLeadingOwnLineComment(options.originalText, n));
+      const shouldIndent = (
+        parent.type !== "TypeParameterInstantiation" &&
+        !(parent.type === "TypeAlias" &&
+          hasLeadingOwnLineComment(options.originalText, n))
+      );
 
       //const token = isIntersection ? "&" : "|";
       const code = concat([

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

@@ -137,3 +137,29 @@ type State = {
 };
 
 `;
+
+exports[`union.js 1`] = `
+type Foo = Promise<
+  { ok: true, bar: string, baz: SomeOtherLongType } | 
+  { ok: false, bar: SomeOtherLongType }
+>;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+type Foo = Promise<
+  | { ok: true, bar: string, baz: SomeOtherLongType }
+  | { ok: false, bar: SomeOtherLongType }
+>;
+
+`;
+
+exports[`union.js 2`] = `
+type Foo = Promise<
+  { ok: true, bar: string, baz: SomeOtherLongType } | 
+  { ok: false, bar: SomeOtherLongType }
+>;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+type Foo = Promise<
+  | { ok: true, bar: string, baz: SomeOtherLongType }
+  | { ok: false, bar: SomeOtherLongType },
+>;
+
+`;

tests/flow_generic/union.js

@@ -0,0 +1,4 @@
+type Foo = Promise<
+  { ok: true, bar: string, baz: SomeOtherLongType } | 
+  { ok: false, bar: SomeOtherLongType }
+>;