hoist-jest.spec.ts

import ts from 'typescript'

import { makeCompiler } from '../__helpers__/fakers'

import { factory as hoistJest, name, version } from './hoist-jest'

const BASE_IMPORT_CODE = `
  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'
`

const CODE_WITH_HOISTING_NO_JEST_GLOBALS =
  BASE_IMPORT_CODE +
  `\n` +
  `
  // 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.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.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 =
  BASE_IMPORT_CODE +
  `\n` +
  `
  import {jest} from '@jest/globals'
  import {jest as aliasedJest} from '@jest/globals'
  import * as JestGlobals from '@jest/globals'

  // 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.unmock('react')
  aliasedJest.deepUnmock('../__test_modules__/Unmocked')
  JestGlobals.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')
  })()

  JestGlobals.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)
      },
    };
  })
  aliasedJest.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')
  aliasedJest.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 = () => {}
  JestGlobals.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 printer = ts.createPrinter()

describe('hoist-jest', () => {
  test('should have correct transformer name and version', () => {
    expect(name).toBe('hoist-jest')
    expect(version).toBe(4)
  })

  test('should hoist correctly when not using @jest/globals', () => {
    const sourceFile = ts.createSourceFile(__filename, CODE_WITH_HOISTING_NO_JEST_GLOBALS, ts.ScriptTarget.ES2015)
    const result = ts.transform(sourceFile, [hoistJest(makeCompiler())])

    const transformedSourceFile = result.transformed[0]

    expect(printer.printFile(transformedSourceFile)).toMatchSnapshot()
  })

  test('should hoist correctly when using with @jest/globals', () => {
    const sourceFile = ts.createSourceFile(__filename, CODE_WITH_HOISTING_HAS_JEST_GLOBALS, ts.ScriptTarget.ES2015)
    const result = ts.transform(sourceFile, [hoistJest(makeCompiler())])

    const transformedSourceFile = result.transformed[0]

    expect(printer.printFile(transformedSourceFile)).toMatchSnapshot()
  })
})