feat(transformer): support hoisting when using @jest/globals (#1937)

Support hoisting when using `@jest/globals`, applying to:

- named import, e.g. `import { jest } from '@jest/globals'`

- aliased named import, e.g. `import {jest as aliasedJest} from '@jest/globals'`

- namespace import, e.g `import * as JestGlobals from '@jest/globals'`

Closes #1593

Author: ahnpnl

e2e/__cases__/hoisting/__test_modules__/banana.ts

@@ -0,0 +1 @@
+export = 'banana'

e2e/__cases__/hoisting/__test_modules__/mockFile.ts

@@ -0,0 +1,4 @@
+jest.mock('./banana', () => {
+  const exports = 'apple'
+  return exports
+})

e2e/__cases__/hoisting/general-hoisting.spec.ts

@@ -4,6 +4,9 @@ import b from './__test_modules__/b'
 import c from './__test_modules__/c'
 import d from './__test_modules__/d'
 
+// The virtual mock call below will be hoisted above this `require` call.
+const virtualModule = require('virtual-module')
+
 // These will all be hoisted above imports
 jest.deepUnmock('./__test_modules__/Unmocked')
 jest.unmock('./__test_modules__/c').unmock('./__test_modules__/d')
@@ -14,13 +17,23 @@ let e: any;
   e = require('./__test_modules__/e').default;
   // hoisted to the top of the function scope
   jest.unmock('./__test_modules__/e')
-})();
+})()
+
+jest.mock('virtual-module', () => 'kiwi', {virtual: true})
 
 // These will not be hoisted
 jest.unmock('./__test_modules__/a').dontMock('./__test_modules__/b')
 jest.unmock('./__test_modules__/' + 'a')
 jest.dontMock('./__test_modules__/Mocked')
 
+it('does not throw during transform', () => {
+  const object = {};
+  // @ts-expect-error
+  object.__defineGetter__('foo', () => 'bar');
+  // @ts-expect-error
+  expect(object.foo).toEqual('bar');
+})
+
 it('hoists unmocked modules before imports', () => {
   // @ts-expect-error
   expect(Unmocked._isMockFunction).toBeUndefined()
@@ -34,16 +47,26 @@ it('hoists unmocked modules before imports', () => {
   expect(d._isMockFunction).toBeUndefined()
   expect(d()).toEqual('unmocked')
 
-  expect(e._isMock).toBe(undefined)
+  expect(e._isMock).toBeUndefined()
   expect(e()).toEqual('unmocked')
-});
+})
 
 it('does not hoist dontMock calls before imports', () => {
   // @ts-expect-error
   expect(Mocked._isMockFunction).toBe(true)
-  expect(new Mocked().isMocked).toEqual(undefined)
+  expect(new Mocked().isMocked).toBeUndefined()
 
   // @ts-expect-error
   expect(b._isMockFunction).toBe(true)
-  expect(b()).toEqual(undefined)
-});
+  expect(b()).toBeUndefined()
+})
+
+it('requires modules that also call jest.mock', () => {
+  require('./__test_modules__/mockFile')
+  const mock = require('./__test_modules__/banana')
+  expect(mock).toEqual('apple')
+})
+
+it('works with virtual modules', () => {
+  expect(virtualModule).toBe('kiwi')
+})

e2e/__cases__/hoisting/import-jest.spec.ts

@@ -2,9 +2,9 @@ import {jest} from '@jest/globals'
 import {jest as aliasedJest} from '@jest/globals'
 import * as JestGlobals from '@jest/globals'
 
-import a from './__test_modules__/a';
-import b from './__test_modules__/b';
-import c from './__test_modules__/c';
+import a from './__test_modules__/a'
+import b from './__test_modules__/b'
+import c from './__test_modules__/c'
 
 // These will be hoisted above imports
 jest.unmock('./__test_modules__/a')
@@ -17,21 +17,17 @@ test('named import', () => {
   // @ts-expect-error
   expect(a._isMockFunction).toBeUndefined()
   expect(a()).toBe('unmocked')
-});
+})
 
 test('aliased named import', () => {
-  // @ts-expect-error TODO: fix aliased named import
-  expect(b._isMockFunction).toBe(true)
-  expect(b()).toBeUndefined()
-  // expect(b._isMockFunction).toBe(undefined)
-  // expect(b()).toBe('unmocked')
-});
+  // @ts-expect-error
+  expect(b._isMockFunction).toBeUndefined()
+  expect(b()).toBe('unmocked')
+})
 
 test('namespace import', () => {
-  // @ts-expect-error TODO: fix namespace import
-  expect(c._isMockFunction).toBe(true)
-  expect(c()).toBeUndefined()
-  // expect(c._isMockFunction).toBe(undefined)
-  // expect(c()).toBe('unmocked')
-});
+  // @ts-expect-error
+  expect(c._isMockFunction).toBeUndefined()
+  expect(c()).toBe('unmocked')
+})
 

e2e/__tests__/__snapshots__/hoisting.test.ts.snap

@@ -10,7 +10,7 @@ exports[`Hoisting should pass using template "default": should pass using templa
   PASS ./import-jest.spec.ts
   
   Test Suites: 2 passed, 2 total
-  Tests:       5 passed, 5 total
+  Tests:       8 passed, 8 total
   Snapshots:   0 total
   Time:        XXs
   Ran all test suites.
@@ -27,7 +27,7 @@ exports[`Hoisting should pass using template "with-babel-7": should pass using t
   PASS ./import-jest.spec.ts
   
   Test Suites: 2 passed, 2 total
-  Tests:       5 passed, 5 total
+  Tests:       8 passed, 8 total
   Snapshots:   0 total
   Time:        XXs
   Ran all test suites.
@@ -44,7 +44,7 @@ exports[`Hoisting should pass using template "with-babel-7-string-config": shoul
   PASS ./import-jest.spec.ts
   
   Test Suites: 2 passed, 2 total
-  Tests:       5 passed, 5 total
+  Tests:       8 passed, 8 total
   Snapshots:   0 total
   Time:        XXs
   Ran all test suites.

e2e/__tests__/hoisting.test.ts

@@ -5,6 +5,7 @@ describe('Hoisting', () => {
   const testCase = configureTestCase('hoisting', {
     writeIo: true,
     jestConfig: {
+      testEnvironment: 'node',
       automock: true,
     },
   })

src/config/__snapshots__/config-set.spec.ts.snap

@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`cacheKey should be a string 1`] = `"{\\"digest\\":\\"a0d51ca854194df8191d0e65c0ca4730f510f332\\",\\"jest\\":{\\"__backported\\":true,\\"globals\\":{}},\\"transformers\\":[\\"hoisting-jest-mock@2\\"],\\"tsJest\\":{\\"compiler\\":\\"typescript\\",\\"diagnostics\\":{\\"ignoreCodes\\":[6059,18002,18003],\\"pretty\\":true,\\"throws\\":true},\\"isolatedModules\\":false,\\"packageJson\\":{\\"kind\\":\\"file\\"},\\"transformers\\":{},\\"tsConfig\\":{\\"kind\\":\\"file\\",\\"value\\":\\"\\"}},\\"tsconfig\\":{\\"options\\":{\\"configFilePath\\":\\"\\",\\"declaration\\":false,\\"inlineSourceMap\\":false,\\"inlineSources\\":true,\\"module\\":1,\\"noEmit\\":false,\\"removeComments\\":false,\\"sourceMap\\":true,\\"target\\":1,\\"types\\":[]},\\"raw\\":{\\"compileOnSave\\":false,\\"compilerOptions\\":{\\"composite\\":true,\\"declaration\\":true,\\"types\\":[]},\\"exclude\\":[\\"foo/**/*\\"],\\"include\\":[\\"bar/**/*\\"]}}}"`;
+exports[`cacheKey should be a string 1`] = `"{\\"digest\\":\\"a0d51ca854194df8191d0e65c0ca4730f510f332\\",\\"jest\\":{\\"__backported\\":true,\\"globals\\":{}},\\"transformers\\":[\\"hoisting-jest-mock@3\\"],\\"tsJest\\":{\\"compiler\\":\\"typescript\\",\\"diagnostics\\":{\\"ignoreCodes\\":[6059,18002,18003],\\"pretty\\":true,\\"throws\\":true},\\"isolatedModules\\":false,\\"packageJson\\":{\\"kind\\":\\"file\\"},\\"transformers\\":{},\\"tsConfig\\":{\\"kind\\":\\"file\\",\\"value\\":\\"\\"}},\\"tsconfig\\":{\\"options\\":{\\"configFilePath\\":\\"\\",\\"declaration\\":false,\\"inlineSourceMap\\":false,\\"inlineSources\\":true,\\"module\\":1,\\"noEmit\\":false,\\"removeComments\\":false,\\"sourceMap\\":true,\\"target\\":1,\\"types\\":[]},\\"raw\\":{\\"compileOnSave\\":false,\\"compilerOptions\\":{\\"composite\\":true,\\"declaration\\":true,\\"types\\":[]},\\"exclude\\":[\\"foo/**/*\\"],\\"include\\":[\\"bar/**/*\\"]}}}"`;
 
 exports[`isTestFile should return a boolean value whether the file matches test pattern 1`] = `true`;
 
@@ -21,7 +21,7 @@ Object {
     "name": undefined,
   },
   "transformers": Array [
-    "hoisting-jest-mock@2",
+    "hoisting-jest-mock@3",
   ],
   "tsJest": Object {
     "babelConfig": undefined,

src/transformers/__snapshots__/hoist-jest.spec.ts.snap

@@ -4,21 +4,71 @@ exports[`hoisting should hoist correctly jest methods 1`] = `
 "\\"use strict\\";
 Object.defineProperty(exports, \\"__esModule\\", { value: true });
 // These will all be hoisted above imports
-jest.deepUnmock('./__test_modules__/Unmocked');
-jest.unmock('./__test_modules__/c').unmock('./__test_modules__/d');
-jest.unmock('./__test_modules__/' + 'a');
-var Unmocked_1 = require(\\"./__test_modules__/Unmocked\\");
-var a_1 = require(\\"./__test_modules__/a\\");
-var b_1 = require(\\"./__test_modules__/b\\");
-var c_1 = require(\\"./__test_modules__/c\\");
-var d_1 = require(\\"./__test_modules__/d\\");
+jest.unmock('react');
+jest.deepUnmock('../__test_modules__/Unmocked');
+jest.unmock('../__test_modules__/c').unmock('../__test_modules__/d');
+jest.mock('../__test_modules__/f', function () {
+    if (!global.CALLS) {
+        global.CALLS = 0;
+    }
+    global.CALLS++;
+    return {
+        _isMock: true,
+        fn: function () {
+            // The \`jest.mock\` transform will allow require, built-ins and globals.
+            var path = require('path');
+            var array = new Array(3);
+            array[0] = path.sep;
+            return jest.fn(function () { return array; });
+        },
+    };
+});
+jest.mock(\\"../__test_modules__/jestBackticks\\");
+jest.mock('virtual-module', function () { return 'kiwi'; }, { virtual: true });
+// This has types that should be ignored by the out-of-scope variables check.
+jest.mock('has-flow-types', function () { return function (props) { return 3; }; }, {
+    virtual: true,
+});
+jest.unmock('../__test_modules__/' + 'a');
+jest.mock('../__test_modules__/f', function () { return MockMethods; });
+var Unmocked_1 = require(\\"../__test_modules__/Unmocked\\");
+var Mocked_1 = require(\\"../__test_modules__/Mocked\\");
+var a_1 = require(\\"../__test_modules__/a\\");
+var b_1 = require(\\"../__test_modules__/b\\");
+var c_1 = require(\\"../__test_modules__/c\\");
+var d_1 = require(\\"../__test_modules__/d\\");
+var jestBackticks_1 = require(\\"../__test_modules__/jestBackticks\\");
+// The virtual mock call below will be hoisted above this \`require\` call.
+var virtualModule = require('virtual-module');
+var e;
+(function () {
+    // hoisted to the top of the function scope
+    jest.unmock('../__test_modules__/e');
+    var _getJestObj = 42;
+    e = require('../__test_modules__/e').default;
+})();
 // These will not be hoisted
-jest.unmock('./__test_modules__/a').dontMock('./__test_modules__/b');
+jest.unmock('../__test_modules__/a').dontMock('../__test_modules__/b');
+jest.dontMock('../__test_modules__/Mocked');
+{
+    // Would error (used before initialization) if hoisted to the top of the scope
+    jest.unmock('../__test_modules__/a');
+    var jest = { unmock: function () { } };
+}
+// This must not throw an error
+var myObject = { mock: function () { } };
+myObject.mock('apple', 27);
+// Variable names prefixed with \`mock\` (ignore case) should not throw as out-of-scope
+var MockMethods = function () { };
 console.log(Unmocked_1.default);
+console.log(Mocked_1.default);
 console.log(a_1.default);
 console.log(b_1.default);
 console.log(c_1.default);
 console.log(d_1.default);
+console.log(e);
+console.log(virtualModule);
+console.log(jestBackticks_1.default);
 "
 `;
 
@@ -30,12 +80,12 @@ var globals_2 = require(\\"@jest/globals\\");
 var JestGlobals = require(\\"@jest/globals\\");
 // These will be hoisted above imports
 globals_1.jest.unmock('../__test_modules__/a');
+globals_2.jest.unmock('../__test_modules__/b');
+JestGlobals.jest.unmock('../__test_modules__/c');
 var a_1 = require(\\"../__test_modules__/a\\");
 var b_1 = require(\\"../__test_modules__/b\\");
 var c_1 = require(\\"../__test_modules__/c\\");
 var d_1 = require(\\"../__test_modules__/d\\");
-globals_2.jest.unmock('../__test_modules__/b');
-JestGlobals.jest.unmock('../__test_modules__/c');
 // These will not be hoisted above imports
 {
     jest_1.unmock('../__test_modules__/d');

src/transformers/hoist-jest.spec.ts

@@ -4,42 +4,100 @@ import * as tsc from 'typescript'
 import * as hoist from './hoist-jest'
 
 const CODE_WITH_HOISTING_NO_JEST_GLOBALS = `
-import Unmocked from './__test_modules__/Unmocked'
-import a from './__test_modules__/a'
-import b from './__test_modules__/b'
-import c from './__test_modules__/c'
-import d from './__test_modules__/d'
+import React from 'react'
+import Unmocked from '../__test_modules__/Unmocked'
+import Mocked from '../__test_modules__/Mocked'
+import a from '../__test_modules__/a'
+import b from '../__test_modules__/b'
+import c from '../__test_modules__/c'
+import d from '../__test_modules__/d'
+import f from '../__test_modules__/f'
+import jestBackticks from '../__test_modules__/jestBackticks'
+
+// The virtual mock call below will be hoisted above this \`require\` call.
+const virtualModule = require('virtual-module')
 
 // These will all be hoisted above imports
-jest.deepUnmock('./__test_modules__/Unmocked')
-jest.unmock('./__test_modules__/c').unmock('./__test_modules__/d')
+jest.unmock('react')
+jest.deepUnmock('../__test_modules__/Unmocked')
+jest.unmock('../__test_modules__/c').unmock('../__test_modules__/d')
+
+let e;
+(function () {
+  const _getJestObj = 42;
+  e = require('../__test_modules__/e').default
+  // hoisted to the top of the function scope
+  jest.unmock('../__test_modules__/e')
+})()
+
+jest.mock('../__test_modules__/f', () => {
+  if (!global.CALLS) {
+    global.CALLS = 0
+  }
+  global.CALLS++
+
+  return {
+    _isMock: true,
+    fn: () => {
+      // The \`jest.mock\` transform will allow require, built-ins and globals.
+      const path = require('path')
+      const array = new Array(3)
+      array[0] = path.sep
+      return jest.fn(() => array)
+    },
+  };
+})
+jest.mock(\`../__test_modules__/jestBackticks\`)
+jest.mock('virtual-module', () => 'kiwi', {virtual: true})
+// This has types that should be ignored by the out-of-scope variables check.
+jest.mock('has-flow-types', () => (props: {children: mixed}) => 3, {
+  virtual: true,
+})
 
 // These will not be hoisted
-jest.unmock('./__test_modules__/a').dontMock('./__test_modules__/b')
-jest.unmock('./__test_modules__/' + 'a')
+jest.unmock('../__test_modules__/a').dontMock('../__test_modules__/b')
+jest.unmock('../__test_modules__/' + 'a')
+jest.dontMock('../__test_modules__/Mocked')
+{
+  const jest = {unmock: () => {}};
+  // Would error (used before initialization) if hoisted to the top of the scope
+  jest.unmock('../__test_modules__/a')
+}
+
+// This must not throw an error
+const myObject = {mock: () => {}}
+myObject.mock('apple', 27)
+
+// Variable names prefixed with \`mock\` (ignore case) should not throw as out-of-scope
+const MockMethods = () => {}
+jest.mock('../__test_modules__/f', () => MockMethods)
 
 console.log(Unmocked)
+console.log(Mocked)
 console.log(a)
 console.log(b)
 console.log(c)
 console.log(d)
+console.log(e)
+console.log(virtualModule)
+console.log(jestBackticks)
 `
 const CODE_WITH_HOISTING_HAS_JEST_GLOBALS = `
-  import a from '../__test_modules__/a';
-  import b from '../__test_modules__/b';
+  import a from '../__test_modules__/a'
+  import b from '../__test_modules__/b'
 
-  import {jest} from '@jest/globals';
-  import {jest as aliasedJest} from '@jest/globals';
-  import * as JestGlobals from '@jest/globals';
+  import {jest} from '@jest/globals'
+  import {jest as aliasedJest} from '@jest/globals'
+  import * as JestGlobals from '@jest/globals'
 
-  import c from '../__test_modules__/c';
-  import d from '../__test_modules__/d';
+  import c from '../__test_modules__/c'
+  import d from '../__test_modules__/d'
 
   // These will be hoisted above imports
 
-  jest.unmock('../__test_modules__/a');
-  aliasedJest.unmock('../__test_modules__/b');
-  JestGlobals.jest.unmock('../__test_modules__/c');
+  jest.unmock('../__test_modules__/a')
+  aliasedJest.unmock('../__test_modules__/b')
+  JestGlobals.jest.unmock('../__test_modules__/c')
 
   // These will not be hoisted above imports
 
@@ -66,7 +124,6 @@ describe('hoisting', () => {
     expect(typeof hoist.factory).toBe('function')
   })
 
-  // TODO: import alias and import * are not hoisted correctly yet, will need to fix
   it.each([CODE_WITH_HOISTING_NO_JEST_GLOBALS, CODE_WITH_HOISTING_HAS_JEST_GLOBALS])(
     'should hoist correctly jest methods',
     (data) => {