Migrate expect to typescript (#7919)

Author: Alcedo Nathaniel De Guzman Jr

CHANGELOG.md

@@ -49,6 +49,7 @@
 - `[@jest/transform]`: Migrate to TypeScript ([#7918](https://github.com/facebook/jest/pull/7918))
 - `[docs]` Add missing import to docs ([#7928](https://github.com/facebook/jest/pull/7928))
 - `[jest-resolve-dependencies]`: Migrate to TypeScript ([#7922](https://github.com/facebook/jest/pull/7922))
+- `[expect]`: Migrate to TypeScript ([#7919](https://github.com/facebook/jest/pull/7919))
 
 ### Performance
 

packages/expect/package.json

@@ -8,8 +8,10 @@
   },
   "license": "MIT",
   "main": "build/index.js",
+  "types": "build/index.d.ts",
   "browser": "build-es5/index.js",
   "dependencies": {
+    "@jest/types": "^24.1.0",
     "ansi-styles": "^3.2.0",
     "jest-get-type": "^24.0.0",
     "jest-matcher-utils": "^24.0.0",

packages/expect/src/asymmetricMatchers.js renamed to packages/expect/src/asymmetricMatchers.ts

@@ -4,37 +4,35 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
  */
 
 import {equals, fnNameFor, hasProperty, isA, isUndefined} from './jasmineUtils';
 
 import {emptyObject} from './utils';
 
-export class AsymmetricMatcher {
+export class AsymmetricMatcher<T> {
+  protected sample: T;
   $$typeof: Symbol;
-  inverse: boolean;
+  inverse?: boolean;
 
-  constructor() {
+  constructor(sample: T) {
     this.$$typeof = Symbol.for('jest.asymmetricMatcher');
+    this.sample = sample;
   }
 }
 
-class Any extends AsymmetricMatcher {
-  sample: any;
-
-  constructor(sample: any) {
-    super();
+class Any extends AsymmetricMatcher<any> {
+  constructor(sample: unknown) {
     if (typeof sample === 'undefined') {
       throw new TypeError(
         'any() expects to be passed a constructor function. ' +
           'Please pass one or use anything() to match any object.',
       );
     }
-    this.sample = sample;
+    super(sample);
   }
 
-  asymmetricMatch(other: any) {
+  asymmetricMatch(other: unknown) {
     if (this.sample == String) {
       return typeof other == 'string' || other instanceof String;
     }
@@ -91,8 +89,8 @@ class Any extends AsymmetricMatcher {
   }
 }
 
-class Anything extends AsymmetricMatcher {
-  asymmetricMatch(other: any) {
+class Anything extends AsymmetricMatcher<void> {
+  asymmetricMatch(other: unknown) {
     return !isUndefined(other) && other !== null;
   }
 
@@ -107,16 +105,13 @@ class Anything extends AsymmetricMatcher {
   }
 }
 
-class ArrayContaining extends AsymmetricMatcher {
-  sample: Array<any>;
-
-  constructor(sample: Array<any>, inverse: boolean = false) {
-    super();
-    this.sample = sample;
+class ArrayContaining extends AsymmetricMatcher<Array<unknown>> {
+  constructor(sample: Array<unknown>, inverse: boolean = false) {
+    super(sample);
     this.inverse = inverse;
   }
 
-  asymmetricMatch(other: Array<any>) {
+  asymmetricMatch(other: Array<unknown>) {
     if (!Array.isArray(this.sample)) {
       throw new Error(
         `You must provide an array to ${this.toString()}, not '` +
@@ -144,16 +139,13 @@ class ArrayContaining extends AsymmetricMatcher {
   }
 }
 
-class ObjectContaining extends AsymmetricMatcher {
-  sample: Object;
-
+class ObjectContaining extends AsymmetricMatcher<Object> {
   constructor(sample: Object, inverse: boolean = false) {
-    super();
-    this.sample = sample;
+    super(sample);
     this.inverse = inverse;
   }
 
-  asymmetricMatch(other: Object) {
+  asymmetricMatch(other: any) {
     if (typeof this.sample !== 'object') {
       throw new Error(
         `You must provide an object to ${this.toString()}, not '` +
@@ -166,8 +158,8 @@ class ObjectContaining extends AsymmetricMatcher {
       for (const property in this.sample) {
         if (
           hasProperty(other, property) &&
-          equals(this.sample[property], other[property]) &&
-          !emptyObject(this.sample[property]) &&
+          equals((this.sample as any)[property], other[property]) &&
+          !emptyObject((this.sample as any)[property]) &&
           !emptyObject(other[property])
         ) {
           return false;
@@ -179,7 +171,7 @@ class ObjectContaining extends AsymmetricMatcher {
       for (const property in this.sample) {
         if (
           !hasProperty(other, property) ||
-          !equals(this.sample[property], other[property])
+          !equals((this.sample as any)[property], other[property])
         ) {
           return false;
         }
@@ -198,19 +190,16 @@ class ObjectContaining extends AsymmetricMatcher {
   }
 }
 
-class StringContaining extends AsymmetricMatcher {
-  sample: string;
-
+class StringContaining extends AsymmetricMatcher<string> {
   constructor(sample: string, inverse: boolean = false) {
-    super();
     if (!isA('String', sample)) {
       throw new Error('Expected is not a string');
     }
-    this.sample = sample;
+    super(sample);
     this.inverse = inverse;
   }
 
-  asymmetricMatch(other: any) {
+  asymmetricMatch(other: string) {
     const result = isA('String', other) && other.includes(this.sample);
 
     return this.inverse ? !result : result;
@@ -225,20 +214,17 @@ class StringContaining extends AsymmetricMatcher {
   }
 }
 
-class StringMatching extends AsymmetricMatcher {
-  sample: RegExp;
-
+class StringMatching extends AsymmetricMatcher<RegExp> {
   constructor(sample: string | RegExp, inverse: boolean = false) {
-    super();
     if (!isA('String', sample) && !isA('RegExp', sample)) {
       throw new Error('Expected is not a String or a RegExp');
     }
+    super(new RegExp(sample));
 
-    this.sample = new RegExp(sample);
     this.inverse = inverse;
   }
 
-  asymmetricMatch(other: any) {
+  asymmetricMatch(other: string) {
     const result = isA('String', other) && this.sample.test(other);
 
     return this.inverse ? !result : result;
@@ -255,9 +241,9 @@ class StringMatching extends AsymmetricMatcher {
 
 export const any = (expectedObject: any) => new Any(expectedObject);
 export const anything = () => new Anything();
-export const arrayContaining = (sample: Array<any>) =>
+export const arrayContaining = (sample: Array<unknown>) =>
   new ArrayContaining(sample);
-export const arrayNotContaining = (sample: Array<any>) =>
+export const arrayNotContaining = (sample: Array<unknown>) =>
   new ArrayContaining(sample, true);
 export const objectContaining = (sample: Object) =>
   new ObjectContaining(sample);

packages/expect/src/extractExpectedAssertionsErrors.js renamed to packages/expect/src/extractExpectedAssertionsErrors.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 {

packages/expect/src/fakeChalk.js renamed to packages/expect/src/fakeChalk.ts

@@ -3,12 +3,11 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
- * @flow
  */
 
 import ansiStyles from 'ansi-styles';
 
-const returnInput = str => str;
+const returnInput = (str: string) => str;
 
 const allColorsAsFunc = Object.keys(ansiStyles)
   .map(style => ({[style]: returnInput}))
@@ -21,4 +20,4 @@ Object.keys(allColorsAsFunc)
     Object.assign(returnInput, style);
   });
 
-module.exports = allColorsAsFunc;
+export = allColorsAsFunc;

packages/expect/src/index.js renamed to packages/expect/src/index.ts

@@ -4,12 +4,10 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
  */
 
-import type {
-  Expect,
-  ExpectationObject,
+import * as matcherUtils from 'jest-matcher-utils';
+import {
   AsyncExpectationResult,
   SyncExpectationResult,
   ExpectationResult,
@@ -18,9 +16,10 @@ import type {
   RawMatcherFn,
   ThrowingMatcherFn,
   PromiseMatcherFn,
-} from 'types/Matchers';
+  ExpectationObject,
+  Expect,
+} from './types';
 
-import * as matcherUtils from 'jest-matcher-utils';
 import {iterableEquality, subsetEquality} from './utils';
 import matchers from './matchers';
 import spyMatchers from './spyMatchers';
@@ -50,21 +49,27 @@ import {
 import extractExpectedAssertionsErrors from './extractExpectedAssertionsErrors';
 
 class JestAssertionError extends Error {
-  matcherResult: any;
+  matcherResult?: SyncExpectationResult;
 }
 
-const isPromise = obj =>
+const isPromise = <T extends any>(obj: any): obj is PromiseLike<T> =>
   !!obj &&
   (typeof obj === 'object' || typeof obj === 'function') &&
   typeof obj.then === 'function';
 
-const createToThrowErrorMatchingSnapshotMatcher = function(matcher) {
-  return function(received: any, testNameOrInlineSnapshot?: string) {
+const createToThrowErrorMatchingSnapshotMatcher = function(
+  matcher: RawMatcherFn,
+) {
+  return function(
+    this: MatcherState,
+    received: any,
+    testNameOrInlineSnapshot?: string,
+  ) {
     return matcher.apply(this, [received, testNameOrInlineSnapshot, true]);
   };
 };
 
-const getPromiseMatcher = (name, matcher) => {
+const getPromiseMatcher = (name: string, matcher: any) => {
   if (name === 'toThrow' || name === 'toThrowError') {
     return createThrowMatcher(name, true);
   } else if (
@@ -77,13 +82,13 @@ const getPromiseMatcher = (name, matcher) => {
   return null;
 };
 
-const expect = (actual: any, ...rest): ExpectationObject => {
+const expect: any = (actual: any, ...rest: Array<any>): ExpectationObject => {
   if (rest.length !== 0) {
     throw new Error('Expect takes at most one argument.');
   }
 
   const allMatchers = getMatchers();
-  const expectation = {
+  const expectation: any = {
     not: {},
     rejects: {not: {}},
     resolves: {not: {}},
@@ -131,7 +136,7 @@ const expect = (actual: any, ...rest): ExpectationObject => {
   return expectation;
 };
 
-const getMessage = message =>
+const getMessage = (message?: () => string) =>
   (message && message()) ||
   matcherUtils.RECEIVED_COLOR('No message was specified for this matcher.');
 
@@ -294,7 +299,7 @@ const makeThrowingMatcher = (
 
     const handlError = (error: Error) => {
       if (
-        matcher[INTERNAL_MATCHER_FLAG] === true &&
+        (matcher as any)[INTERNAL_MATCHER_FLAG] === true &&
         !(error instanceof JestAssertionError) &&
         error.name !== 'PrettyFormatPluginError' &&
         // Guard for some environments (browsers) that do not support this feature.
@@ -309,10 +314,13 @@ const makeThrowingMatcher = (
     let potentialResult: ExpectationResult;
 
     try {
-      potentialResult = matcher.apply(matcherContext, [actual].concat(args));
+      potentialResult = matcher.apply(
+        matcherContext,
+        ([actual] as any).concat(args),
+      );
 
-      if (isPromise((potentialResult: any))) {
-        const asyncResult = ((potentialResult: any): AsyncExpectationResult);
+      if (isPromise(potentialResult)) {
+        const asyncResult = potentialResult as AsyncExpectationResult;
         const asyncError = new JestAssertionError();
         if (Error.captureStackTrace) {
           Error.captureStackTrace(asyncError, throwingMatcher);
@@ -322,7 +330,7 @@ const makeThrowingMatcher = (
           .then(aResult => processResult(aResult, asyncError))
           .catch(error => handlError(error));
       } else {
-        const syncResult = ((potentialResult: any): SyncExpectationResult);
+        const syncResult = potentialResult as SyncExpectationResult;
 
         return processResult(syncResult);
       }
@@ -332,7 +340,7 @@ const makeThrowingMatcher = (
   };
 
 expect.extend = (matchers: MatchersObject): void =>
-  setMatchers(matchers, false, expect);
+  setMatchers(matchers, false, expect as any);
 
 expect.anything = anything;
 expect.any = any;
@@ -349,7 +357,7 @@ expect.arrayContaining = arrayContaining;
 expect.stringContaining = stringContaining;
 expect.stringMatching = stringMatching;
 
-const _validateResult = result => {
+const _validateResult = (result: any) => {
   if (
     typeof result !== 'object' ||
     typeof result.pass !== 'boolean' ||
@@ -376,7 +384,7 @@ function assertions(expected: number) {
   getState().expectedAssertionsNumber = expected;
   getState().expectedAssertionsNumberError = error;
 }
-function hasAssertions(...args) {
+function hasAssertions(...args: Array<any>) {
   const error = new Error();
   if (Error.captureStackTrace) {
     Error.captureStackTrace(error, hasAssertions);
@@ -388,9 +396,9 @@ function hasAssertions(...args) {
 }
 
 // add default jest matchers
-setMatchers(matchers, true, expect);
-setMatchers(spyMatchers, true, expect);
-setMatchers(toThrowMatchers, true, expect);
+setMatchers(matchers, true, expect as Expect);
+setMatchers(spyMatchers, true, expect as Expect);
+setMatchers(toThrowMatchers, true, expect as Expect);
 
 expect.addSnapshotSerializer = () => void 0;
 expect.assertions = assertions;
@@ -399,4 +407,4 @@ expect.getState = getState;
 expect.setState = setState;
 expect.extractExpectedAssertionsErrors = extractExpectedAssertionsErrors;
 
-module.exports = (expect: Expect);
+export = expect as Expect;