jestjs · SimenB · Dec 26, 2018 · Oct 7, 2018 · Dec 26, 2018
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -105,6 +105,7 @@
 ### Chore & Maintenance
 
 - `[*]` [**BREAKING**] Require Node.js 6+ for all packages ([#7258](https://github.com/facebook/jest/pull/7258))
+- `[*]` [**BREAKING**] Use ESM `import` and `export` all over ([#7548](https://github.com/facebook/jest/pull/7548))
 - `[jest-util]` [**BREAKING**] Remove long-deprecated globals for fake timers ([#7285](https://github.com/facebook/jest/pull/7285))
 - `[docs]` Fix message property in custom matcher example to return a function instead of a constant. ([#7426](https://github.com/facebook/jest/pull/7426))
 - `[jest-circus]` Standardize file naming in `jest-circus` ([#7301](https://github.com/facebook/jest/pull/7301))

diff --git a/e2e/__tests__/__snapshots__/module_name_mapper.test.js.snap b/e2e/__tests__/__snapshots__/module_name_mapper.test.js.snap
@@ -32,7 +32,7 @@ exports[`moduleNameMapper wrong configuration 1`] = `
       12 | module.exports = () => 'test';
       13 | 
 
-      at packages/jest-resolve/build/index.js:433:17
+      at packages/jest-resolve/build/index.js:452:17
       at index.js:10:1
 
 "

diff --git a/e2e/__tests__/__snapshots__/resolve_no_file_extensions.test.js.snap b/e2e/__tests__/__snapshots__/resolve_no_file_extensions.test.js.snap
@@ -33,7 +33,7 @@ exports[`show error message with matching files 1`] = `
         |                  ^
       4 | 
 
-      at packages/jest-resolve/build/index.js:200:17
+      at packages/jest-resolve/build/index.js:217:17
       at index.js:3:18
 
 "

diff --git a/e2e/browser-support/browser-test.js b/e2e/browser-support/browser-test.js
@@ -6,9 +6,9 @@
  */
 
 /* eslint-disable */
-var expect = require('../../packages/expect/build-es5/index.js');
+var {default: expect} = require('../../packages/expect/build-es5/index.js');
 var mock = require('../../packages/jest-mock/build-es5/index.js');
-var prettyFormat = require('../../packages/pretty-format/build-es5/index.js');
+var {default: prettyFormat} = require('../../packages/pretty-format/build-es5/index.js');
 
 describe('es5 builds in browser', function() {
   it('runs assertions', function() {

diff --git a/e2e/runJest.js b/e2e/runJest.js
@@ -12,7 +12,7 @@ import path from 'path';
 import fs from 'fs';
 import execa, {sync as spawnSync} from 'execa';
 import {Writable} from 'readable-stream';
-const stripAnsi = require('strip-ansi');
+import stripAnsi from 'strip-ansi';
 import {normalizeIcons} from './Utils';
 
 const JEST_PATH = path.resolve(__dirname, '../packages/jest-cli/bin/jest.js');

diff --git a/e2e/test-environment-async/TestEnvironment.js b/e2e/test-environment-async/TestEnvironment.js
@@ -5,7 +5,7 @@
 const fs = require('fs');
 const os = require('os');
 const mkdirp = require('mkdirp');
-const JSDOMEnvironment = require('jest-environment-jsdom');
+const JSDOMEnvironment = require('jest-environment-jsdom').default;
 
 const DIR = os.tmpdir() + '/jest-test-environment';
 

diff --git a/packages/babel-jest/src/__tests__/index.js b/packages/babel-jest/src/__tests__/index.js
@@ -4,7 +4,8 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
-const babelJest = require('../index');
+
+import babelJest from '../index';
 
 //Mock data for all the tests
 const sourceString = `

diff --git a/packages/babel-jest/src/index.js b/packages/babel-jest/src/index.js
@@ -24,7 +24,7 @@ import babelIstanbulPlugin from 'babel-plugin-istanbul';
 const THIS_FILE = fs.readFileSync(__filename);
 const jestPresetPath = require.resolve('babel-preset-jest');
 
-const createTransformer = (options: any): Transformer => {
+export const createTransformer = (options: any): Transformer => {
   options = Object.assign({}, options, {
     compact: false,
     plugins: (options && options.plugins) || [],
@@ -110,5 +110,4 @@ const createTransformer = (options: any): Transformer => {
   };
 };
 
-module.exports = createTransformer();
-(module.exports: any).createTransformer = createTransformer;
+export default createTransformer();
diff --git a/packages/babel-plugin-jest-hoist/src/index.js b/packages/babel-plugin-jest-hoist/src/index.js
@@ -139,7 +139,7 @@ FUNCTIONS.deepUnmock = args => args.length === 1 && args[0].isStringLiteral();
 FUNCTIONS.disableAutomock = FUNCTIONS.enableAutomock = args =>
   args.length === 0;
 
-module.exports = () => {
+export default () => {
   const isJest = callee =>
     callee.get('object').isIdentifier(JEST_GLOBAL) ||
     (callee.isMemberExpression() && isJest(callee.get('object')));

diff --git a/packages/expect/src/__tests__/assertionCounts.test.js b/packages/expect/src/__tests__/assertionCounts.test.js
@@ -8,35 +8,35 @@
 
 'use strict';
 
-const jestExpect = require('../');
+import jestExpect, {assertions, hasAssertions} from '../';
 
 describe('.assertions()', () => {
   it('does not throw', () => {
-    jestExpect.assertions(2);
+    assertions(2);
     jestExpect('a').not.toBe('b');
     jestExpect('a').toBe('a');
   });
 
   it('redeclares different assertion count', () => {
-    jestExpect.assertions(3);
+    assertions(3);
     jestExpect('a').not.toBe('b');
     jestExpect('a').toBe('a');
-    jestExpect.assertions(2);
+    assertions(2);
   });
   it('expects no assertions', () => {
-    jestExpect.assertions(0);
+    assertions(0);
   });
 });
 
 describe('.hasAssertions()', () => {
   it('does not throw if there is an assertion', () => {
-    jestExpect.hasAssertions();
+    hasAssertions();
     jestExpect('a').toBe('a');
   });
 
   it('throws if expected is not undefined', () => {
     jestExpect(() => {
-      jestExpect.hasAssertions(2);
+      hasAssertions(2);
     }).toThrowErrorMatchingSnapshot();
   });
 

diff --git a/packages/expect/src/__tests__/asymmetricMatchers.test.js b/packages/expect/src/__tests__/asymmetricMatchers.test.js
@@ -8,19 +8,19 @@
 
 'use strict';
 
-const jestExpect = require('../');
-const {
+import jestExpect from '../';
+import {
   any,
   anything,
   arrayContaining,
   arrayNotContaining,
   objectContaining,
   objectNotContaining,
   stringContaining,
-  stringNotContaining,
   stringMatching,
+  stringNotContaining,
   stringNotMatching,
-} = require('../asymmetricMatchers');
+} from '../asymmetricMatchers';
 
 test('Any.asymmetricMatch()', () => {
   const Thing = function() {};

diff --git a/packages/expect/src/__tests__/extend.test.js b/packages/expect/src/__tests__/extend.test.js
@@ -6,10 +6,10 @@
  *
  */
 
-const matcherUtils = require('jest-matcher-utils');
-const {iterableEquality, subsetEquality} = require('../utils');
-const {equals} = require('../jasmineUtils');
-const jestExpect = require('../');
+import * as matcherUtils from 'jest-matcher-utils';
+import {iterableEquality, subsetEquality} from '../utils';
+import {equals} from '../jasmineUtils';
+import jestExpect from '../';
 
 jestExpect.extend({
   toBeDivisibleBy(actual, expected) {

diff --git a/packages/expect/src/__tests__/matchers.test.js b/packages/expect/src/__tests__/matchers.test.js
@@ -6,10 +6,11 @@
  *
  */
 
-const {stringify} = require('jest-matcher-utils');
-const jestExpect = require('../');
-const Immutable = require('immutable');
-const chalk = require('chalk');
+import {stringify} from 'jest-matcher-utils';
+import jestExpect from '../';
+import Immutable from 'immutable';
+import chalk from 'chalk';
+
 const chalkEnabled = chalk.enabled;
 
 beforeAll(() => {

diff --git a/packages/expect/src/__tests__/spyMatchers.test.js b/packages/expect/src/__tests__/spyMatchers.test.js
@@ -6,8 +6,8 @@
  *
  */
 
-const Immutable = require('immutable');
-const jestExpect = require('../');
+import Immutable from 'immutable';
+import jestExpect from '../';
 
 ['toBeCalled', 'toHaveBeenCalled'].forEach(called => {
   describe(`${called}`, () => {

diff --git a/packages/expect/src/__tests__/stacktrace.test.js b/packages/expect/src/__tests__/stacktrace.test.js
@@ -6,7 +6,7 @@
  *
  */
 
-const jestExpect = require('../');
+import jestExpect from '../';
 
 jestExpect.extend({
   toCustomMatch(callback, expectation) {

diff --git a/packages/expect/src/__tests__/toThrowMatchers.test.js b/packages/expect/src/__tests__/toThrowMatchers.test.js
@@ -8,7 +8,7 @@
 
 'use strict';
 
-const jestExpect = require('../');
+import jestExpect from '../';
 
 // Custom Error class because node versions have different stack trace strings.
 class customError extends Error {

diff --git a/packages/expect/src/__tests__/utils.test.js b/packages/expect/src/__tests__/utils.test.js
@@ -8,14 +8,14 @@
 
 'use strict';
 
-const {stringify} = require('jest-matcher-utils');
-const {
+import {stringify} from 'jest-matcher-utils';
+import {
   emptyObject,
   getObjectSubset,
   getPath,
   hasOwnProperty,
   subsetEquality,
-} = require('../utils');
+} from '../utils';
 
 describe('getPath()', () => {
   test('property exists', () => {

diff --git a/packages/expect/src/index.js b/packages/expect/src/index.js
@@ -8,7 +8,6 @@
  */
 
 import type {
-  Expect,
   ExpectationObject,
   AsyncExpectationResult,
   SyncExpectationResult,
@@ -47,7 +46,12 @@ import {
   getMatchers,
   setMatchers,
 } from './jestMatchersObject';
-import extractExpectedAssertionsErrors from './extractExpectedAssertionsErrors';
+
+export {
+  default as extractExpectedAssertionsErrors,
+} from './extractExpectedAssertionsErrors';
+
+export {getState, setState};
 
 class JestAssertionError extends Error {
   matcherResult: any;
@@ -77,7 +81,7 @@ const getPromiseMatcher = (name, matcher) => {
   return null;
 };
 
-const expect = (actual: any, ...rest): ExpectationObject => {
+const expect = (actual: any, ...rest: Array<any>): ExpectationObject => {
   if (rest.length !== 0) {
     throw new Error('Expect takes at most one argument.');
   }
@@ -316,9 +320,11 @@ const makeThrowingMatcher = (
     }
   };
 
-expect.extend = (matchers: MatchersObject): void =>
+export const extend = (matchers: MatchersObject): void =>
   setMatchers(matchers, false, expect);
 
+expect.extend = extend;
+
 expect.anything = anything;
 expect.any = any;
 
@@ -352,7 +358,7 @@ const _validateResult = result => {
   }
 };
 
-function assertions(expected: number) {
+export function assertions(expected: number) {
   const error = new Error();
   if (Error.captureStackTrace) {
     Error.captureStackTrace(error, assertions);
@@ -361,7 +367,7 @@ function assertions(expected: number) {
   getState().expectedAssertionsNumber = expected;
   getState().expectedAssertionsNumberError = error;
 }
-function hasAssertions(...args) {
+export function hasAssertions(...args: Array<any>) {
   const error = new Error();
   if (Error.captureStackTrace) {
     Error.captureStackTrace(error, hasAssertions);
@@ -377,11 +383,6 @@ setMatchers(matchers, true, expect);
 setMatchers(spyMatchers, true, expect);
 setMatchers(toThrowMatchers, true, expect);
 
-expect.addSnapshotSerializer = () => void 0;
-expect.assertions = assertions;
-expect.hasAssertions = hasAssertions;
-expect.getState = getState;
-expect.setState = setState;
-expect.extractExpectedAssertionsErrors = extractExpectedAssertionsErrors;
+export const addSnapshotSerializer = () => void 0;
 
-module.exports = (expect: Expect);
+export default expect;
diff --git a/packages/expect/src/jestMatchersObject.js b/packages/expect/src/jestMatchersObject.js
@@ -8,11 +8,7 @@
  */
 
 import {AsymmetricMatcher} from './asymmetricMatchers';
-import type {
-  Expect,
-  MatchersObject,
-  SyncExpectationResult,
-} from 'types/Matchers';
+import type {MatchersObject, SyncExpectationResult} from 'types/Matchers';
 
 // Global matchers object holds the list of available matchers and
 // the state, that can hold matcher specific values that change over time.
@@ -47,7 +43,7 @@ export const getMatchers = () => global[JEST_MATCHERS_OBJECT].matchers;
 export const setMatchers = (
   matchers: MatchersObject,
   isInternal: boolean,
-  expect: Expect,
+  expect: any,
 ) => {
   Object.keys(matchers).forEach(key => {
     const matcher = matchers[key];

diff --git a/packages/jest-circus/src/__tests__/circusItTestError.test.js b/packages/jest-circus/src/__tests__/circusItTestError.test.js
@@ -9,19 +9,9 @@
 
 'use strict';
 
-let circusIt;
-let circusTest;
-
 // using jest-jasmine2's 'it' to test jest-circus's 'it'. Had to differentiate
 // the two with this alias.
-
-const aliasCircusIt = () => {
-  const {it, test} = require('../index.js');
-  circusIt = it;
-  circusTest = test;
-};
-
-aliasCircusIt();
+import {it as circusIt, test as circusTest} from '../index.js';
 
 // A few of these tests require incorrect types to throw errors and thus pass
 // the test. The typechecks on jest-circus would prevent that, so

diff --git a/packages/jest-circus/src/__tests__/circusItTodoTestError.test.js b/packages/jest-circus/src/__tests__/circusItTodoTestError.test.js
@@ -9,17 +9,9 @@
 
 'use strict';
 
-let circusIt;
-
 // using jest-jasmine2's 'it' to test jest-circus's 'it'. Had to differentiate
 // the two with this alias.
-
-const aliasCircusIt = () => {
-  const {it} = require('../index.js');
-  circusIt = it;
-};
-
-aliasCircusIt();
+import {it as circusIt} from '../index.js';
 
 describe('test/it.todo error throwing', () => {
   it('todo throws error when given no arguments', () => {

diff --git a/packages/jest-circus/src/__tests__/hooksError.test.js b/packages/jest-circus/src/__tests__/hooksError.test.js
@@ -9,7 +9,7 @@
 
 'use strict';
 
-const circus = require('../index.js');
+import * as circus from '../index.js';
 
 describe.each([['beforeEach'], ['beforeAll'], ['afterEach'], ['afterAll']])(
   '%s hooks error throwing',
@@ -27,6 +27,7 @@ describe.each([['beforeEach'], ['beforeAll'], ['afterEach'], ['afterAll']])(
       `${fn} throws an error when %p is provided as a first argument to it`,
       el => {
         expect(() => {
+          // eslint-disable-next-line import/namespace
           circus[fn](el);
         }).toThrowError(
           'Invalid first argument. It must be a callback function.',