Migrate diff-sequences to Typescript (#7820)

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 - `[*]`: Setup building, linting and testing of TypeScript ([#7808](https://github.com/facebook/jest/pull/7808))
 - `[pretty-format]`: Migrate to TypeScript ([#7809](https://github.com/facebook/jest/pull/7809))
+- `[diff-sequences]`: Migrate to Typescript ([#7820](https://github.com/facebook/jest/pull/7820))
 
 ### Performance
 

packages/diff-sequences/package.json

@@ -19,6 +19,7 @@
     "node": ">= 6"
   },
   "main": "build/index.js",
+  "types": "build/index.d.ts",
   "scripts": {
     "perf": "node --expose-gc perf/index.js"
   },

packages/diff-sequences/src/__tests__/index.test.js → packages/diff-sequences/src/__tests__/index.test.ts

@@ -4,7 +4,6 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
  */
 
 import diff from '../';
@@ -16,7 +15,7 @@ describe('invalid arg', () => {
   describe('length', () => {
     test('is not a number', () => {
       expect(() => {
-        diff(('0': any), 0, isCommon, foundSubsequence);
+        diff('0' as any, 0, isCommon, foundSubsequence);
       }).toThrow(/aLength/);
     });
     test('Infinity is not a safe integer', () => {
@@ -50,12 +49,12 @@ describe('invalid arg', () => {
   describe('callback', () => {
     test('null is not a function', () => {
       expect(() => {
-        diff(0, 0, (null: any), foundSubsequence);
+        diff(0, 0, null as any, foundSubsequence);
       }).toThrow(/isCommon/);
     });
     test('undefined is not a function', () => {
       expect(() => {
-        diff(0, 0, isCommon, (undefined: any));
+        diff(0, 0, isCommon, undefined as any);
       }).toThrow(/foundSubsequence/);
     });
   });

packages/diff-sequences/src/index.js → packages/diff-sequences/src/index.ts

@@ -4,7 +4,6 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
  */
 
 // This diff-sequences package implements the linear space variation in
@@ -66,10 +65,10 @@ type FoundSubsequence = (
 ) => void;
 
 // Either original functions or wrapped to swap indexes if graph is transposed.
-type Callbacks = {|
-  foundSubsequence: FoundSubsequence,
-  isCommon: IsCommon,
-|};
+type Callbacks = {
+  foundSubsequence: FoundSubsequence;
+  isCommon: IsCommon;
+};
 
 // Indexes in sequence a of last point of forward or reverse paths in graph.
 // Myers algorithm indexes by diagonal k which for negative is bad deopt in V8.
@@ -81,25 +80,25 @@ type Indexes = Array<number>;
 
 // Division of index intervals in sequences a and b at the middle change.
 // Invariant: intervals do not have common items at the start or end.
-type Division = {|
+type Division = {
   // The end of interval preceding division is open like array slice method.
-  nChangePreceding: number, // number of change items
-  aEndPreceding: number,
-  bEndPreceding: number,
+  nChangePreceding: number; // number of change items
+  aEndPreceding: number;
+  bEndPreceding: number;
 
-  nCommonPreceding: number, // 0 if no common items preceding middle change
-  aCommonPreceding: number, // ignore prop value if nCommonPreceding === 0
-  bCommonPreceding: number, // ignore prop value if nCommonPreceding === 0
+  nCommonPreceding: number; // 0 if no common items preceding middle change
+  aCommonPreceding: number; // ignore prop value if nCommonPreceding === 0
+  bCommonPreceding: number; // ignore prop value if nCommonPreceding === 0
 
-  nCommonFollowing: number, // 0 if no common items following middle change
-  aCommonFollowing: number, // ignore prop value if nCommonFollowing === 0
-  bCommonFollowing: number, // ignore prop value if nCommonFollowing === 0
+  nCommonFollowing: number; // 0 if no common items following middle change
+  aCommonFollowing: number; // ignore prop value if nCommonFollowing === 0
+  bCommonFollowing: number; // ignore prop value if nCommonFollowing === 0
 
   // The start of interval following division is closed like array slice method.
-  nChangeFollowing: number, // number of change items
-  aStartFollowing: number,
-  bStartFollowing: number,
-|};
+  nChangeFollowing: number; // number of change items
+  aStartFollowing: number;
+  bStartFollowing: number;
+};
 
 const pkg = 'diff-sequences'; // for error messages
 const NOT_YET_SET = 0; // small int instead of undefined to avoid deopt in V8

packages/diff-sequences/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "build"
+  }
+}