Support new Flow variance syntax (#19102)

Co-authored-by: fisker Cheung <lionkay@gmail.com>

tests/format/flow/in-out-variance/__snapshots__/format.test.js.snap

@@ -0,0 +1,38 @@
+// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
+
+exports[`in-out-variance.js format 1`] = `
+====================================options=====================================
+parsers: ["flow"]
+                                                      printWidth: 80 (default) |
+=====================================input======================================
+type Contravariant<  in   T  > = T;
+
+type Covariant<  out   T  > = T;
+
+type Mixed<  in   T,   out   U  > = T;
+
+type InNamedIn<  in   in  > = void;
+
+type OutNamedOut<  out   out  > = void;
+
+type InWithBound<  in   T:   number  > = T;
+
+type OutWithDefault<  out   T  =   string  > = T;
+
+=====================================output=====================================
+type Contravariant<in T> = T;
+
+type Covariant<out T> = T;
+
+type Mixed<in T, out U> = T;
+
+type InNamedIn<in in> = void;
+
+type OutNamedOut<out out> = void;
+
+type InWithBound<in T: number> = T;
+
+type OutWithDefault<out T = string> = T;
+
+================================================================================
+`;

tests/format/flow/in-out-variance/format.test.js

@@ -0,0 +1,5 @@
+runFormatTest(import.meta, ["flow"], {
+  errors: {
+    "babel-flow": true,
+  },
+});

tests/format/flow/in-out-variance/in-out-variance.js

@@ -0,0 +1,13 @@
+type Contravariant<  in   T  > = T;
+
+type Covariant<  out   T  > = T;
+
+type Mixed<  in   T,   out   U  > = T;
+
+type InNamedIn<  in   in  > = void;
+
+type OutNamedOut<  out   out  > = void;
+
+type InWithBound<  in   T:   number  > = T;
+
+type OutWithDefault<  out   T  =   string  > = T;

tests/format/flow/variance/__snapshots__/format.test.js.snap

@@ -24,6 +24,13 @@ type ReadonlyInterface = interface {
       readonly   prop:   string
 };
 
+type ReadonlyReservedWords = {
+  readonly   with:   string,
+  readonly   default?:   string,
+  readonly   enum:   number,
+  readonly   new:   boolean,
+};
+
 =====================================output=====================================
 class Route {
   static +param: T;
@@ -44,5 +51,12 @@ type ReadonlyInterface = interface {
   readonly prop: string,
 };
 
+type ReadonlyReservedWords = {
+  readonly with: string,
+  readonly default?: string,
+  readonly enum: number,
+  readonly new: boolean,
+};
+
 ================================================================================
 `;

tests/format/flow/variance/variance.js

@@ -16,3 +16,10 @@ type ReadonlyTuple = [  readonly   label:   number  ];
 type ReadonlyInterface = interface {
       readonly   prop:   string
 };
+
+type ReadonlyReservedWords = {
+  readonly   with:   string,
+  readonly   default?:   string,
+  readonly   enum:   number,
+  readonly   new:   boolean,
+};

tests/format/flow/writeonly/__snapshots__/format.test.js.snap

@@ -0,0 +1,30 @@
+// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
+
+exports[`writeonly.js format 1`] = `
+====================================options=====================================
+parsers: ["flow"]
+                                                      printWidth: 80 (default) |
+=====================================input======================================
+type WriteonlyObj = {
+    writeonly   foo:   string,
+  writeonly [string]:   unknown
+};
+
+type WriteonlyReservedWords = {
+  writeonly   with:   string,
+  writeonly   default?:   string,
+};
+
+=====================================output=====================================
+type WriteonlyObj = {
+  writeonly foo: string,
+  writeonly [string]: unknown,
+};
+
+type WriteonlyReservedWords = {
+  writeonly with: string,
+  writeonly default?: string,
+};
+
+================================================================================
+`;

tests/format/flow/writeonly/format.test.js

@@ -0,0 +1,5 @@
+runFormatTest(import.meta, ["flow"], {
+  errors: {
+    "babel-flow": true,
+  },
+});

tests/format/flow/writeonly/writeonly.js

@@ -0,0 +1,9 @@
+type WriteonlyObj = {
+    writeonly   foo:   string,
+  writeonly [string]:   unknown
+};
+
+type WriteonlyReservedWords = {
+  writeonly   with:   string,
+  writeonly   default?:   string,
+};