[jest-each] Migrate to Typescript (#8007)

Author: mattphillips

CHANGELOG.md

@@ -32,6 +32,7 @@
 
 ### Chore & Maintenance
 
+- `[jest-each]`: Migrate to Typescript ([#8007](https://github.com/facebook/jest/pull/8007))
 - `[jest-environment-jsdom]`: Migrate to TypeScript ([#7985](https://github.com/facebook/jest/pull/8003))
 - `[jest-environment-node]`: Migrate to TypeScript ([#7985](https://github.com/facebook/jest/pull/7985))
 - `[*]`: Setup building, linting and testing of TypeScript ([#7808](https://github.com/facebook/jest/pull/7808), [#7855](https://github.com/facebook/jest/pull/7855), [#7951](https://github.com/facebook/jest/pull/7951))

packages/jest-circus/src/index.ts

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
-// @ts-ignore TODO Remove ignore when jest-each is migrated to ts
+
 import {bind as bindEach} from 'jest-each';
 import {ErrorWithStack} from 'jest-util';
 import {Global} from '@jest/types';

packages/jest-circus/tsconfig.json

@@ -6,6 +6,7 @@
   },
   "references": [
     {"path": "../jest-diff"},
+    {"path": "../jest-each"},
     {"path": "../jest-environment"},
     {"path": "../jest-matcher-utils"},
     {"path": "../jest-message-util"},

packages/jest-each/package.json

@@ -3,6 +3,7 @@
   "version": "24.0.0",
   "description": "Parameterised tests for Jest",
   "main": "build/index.js",
+  "types": "build/index.d.ts",
   "repository": {
     "type": "git",
     "url": "https://github.com/facebook/jest.git",
@@ -17,6 +18,7 @@
   "author": "Matt Phillips (mattphillips)",
   "license": "MIT",
   "dependencies": {
+    "@jest/types": "^24.1.0",
     "chalk": "^2.0.1",
     "jest-get-type": "^24.0.0",
     "jest-util": "^24.0.0",

packages/jest-each/src/__tests__/__snapshots__/array.test.js.snap renamed to packages/jest-each/src/__tests__/__snapshots__/array.test.ts.snap

@@ -16,7 +16,7 @@ const get = (object, lensPath) =>
   lensPath.reduce((acc, key) => acc[key], object);
 
 const getGlobalTestMocks = () => {
-  const globals = {
+  const globals: any = {
     describe: jest.fn(),
     fdescribe: jest.fn(),
     fit: jest.fn(),

packages/jest-each/src/__tests__/__snapshots__/template.test.js.snap renamed to packages/jest-each/src/__tests__/__snapshots__/template.test.ts.snap

@@ -15,7 +15,7 @@ const get = (object, lensPath) =>
   lensPath.reduce((acc, key) => acc[key], object);
 
 const getGlobalTestMocks = () => {
-  const globals = {
+  const globals: any = {
     describe: jest.fn(),
     fdescribe: jest.fn(),
     fit: jest.fn(),

packages/jest-each/src/__tests__/array.test.js renamed to packages/jest-each/src/__tests__/array.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 util from 'util';
@@ -15,8 +14,8 @@ import {ErrorWithStack} from 'jest-util';
 
 type Table = Array<Array<any>>;
 type PrettyArgs = {
-  args: Array<mixed>,
-  title: string,
+  args: Array<any>;
+  title: string;
 };
 
 const EXPECTED_COLOR = chalk.green;
@@ -26,7 +25,7 @@ const PRETTY_PLACEHOLDER = '%p';
 const INDEX_PLACEHOLDER = '%#';
 
 export default (cb: Function, supportsDone: boolean = true) => (...args: any) =>
-  function eachBind(title: string, test: Function, timeout: number): void {
+  function eachBind(title: string, test: Function, timeout?: number): void {
     if (args.length === 1) {
       const [tableArg] = args;
 
@@ -122,19 +121,20 @@ export default (cb: Function, supportsDone: boolean = true) => (...args: any) =>
     );
   };
 
-const isTaggedTemplateLiteral = array => array.raw !== undefined;
-const isEmptyTable = table => table.length === 0;
-const isEmptyString = str => typeof str === 'string' && str.trim() === '';
+const isTaggedTemplateLiteral = (array: any) => array.raw !== undefined;
+const isEmptyTable = (table: Array<any>) => table.length === 0;
+const isEmptyString = (str: string) =>
+  typeof str === 'string' && str.trim() === '';
 
-const getPrettyIndexes = placeholders =>
-  placeholders.reduce((indexes, placeholder, index) => {
+const getPrettyIndexes = (placeholders: RegExpMatchArray) =>
+  placeholders.reduce((indexes: Array<number>, placeholder, index) => {
     if (placeholder === PRETTY_PLACEHOLDER) {
       indexes.push(index);
     }
     return indexes;
   }, []);
 
-const arrayFormat = (title, rowIndex, ...args) => {
+const arrayFormat = (title: string, rowIndex: number, ...args: Array<any>) => {
   const placeholders = title.match(SUPPORTED_PLACEHOLDERS) || [];
   const prettyIndexes = getPrettyIndexes(placeholders);
 
@@ -164,13 +164,15 @@ const arrayFormat = (title, rowIndex, ...args) => {
   );
 };
 
+type Done = () => {};
+
 const applyRestParams = (
   supportsDone: boolean,
   params: Array<any>,
   test: Function,
 ) =>
   supportsDone && params.length < test.length
-    ? done => test(...params, done)
+    ? (done: Done) => test(...params, done)
     : () => test(...params);
 
 const getHeadingKeys = (headings: string): Array<string> =>
@@ -190,10 +192,15 @@ const buildTable = (
       ),
     );
 
-const getMatchingKeyPaths = title => (matches, key) =>
-  matches.concat(title.match(new RegExp(`\\$${key}[\\.\\w]*`, 'g')) || []);
+const getMatchingKeyPaths = (title: string) => (
+  matches: Array<string>,
+  key: string,
+) => matches.concat(title.match(new RegExp(`\\$${key}[\\.\\w]*`, 'g')) || []);
 
-const replaceKeyPathWithValue = data => (title, match) => {
+const replaceKeyPathWithValue = (data: any) => (
+  title: string,
+  match: string,
+) => {
   const keyPath = match.replace('$', '').split('.');
   const value = getPath(data, keyPath);
 
@@ -209,12 +216,17 @@ const interpolate = (title: string, data: any) =>
     .reduce(replaceKeyPathWithValue(data), title);
 
 const applyObjectParams = (supportsDone: boolean, obj: any, test: Function) =>
-  supportsDone && test.length > 1 ? done => test(obj, done) : () => test(obj);
+  supportsDone && test.length > 1
+    ? (done: Done) => test(obj, done)
+    : () => test(obj);
 
 const pluralize = (word: string, count: number) =>
   word + (count === 1 ? '' : 's');
 
-const getPath = (o: Object, [head, ...tail]: Array<string>) => {
+const getPath = (
+  o: {[key: string]: any},
+  [head, ...tail]: Array<string>,
+): any => {
   if (!head || !o.hasOwnProperty || !o.hasOwnProperty(head)) return o;
   return getPath(o[head], tail);
 };