@finos/legend-dev-utils/JestConfigUtils.js

Legend Studio development utilities, helpers, and scripts

/**
 * Copyright (c) 2020-present, Goldman Sachs
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

export const getBaseConfig = ({
  /**
   * Absolute path to the Babel config file
   */
  babelConfigPath,
  /**
   * ESM packages that need transformation to work with Jest
   */
  TEMPORARY__esmPackagesToTransform,
  /**
   * Indicates if the config being generated is meant for global Jest config
   */
  isGlobal,
}) => {
  /** @type {import('jest').Config} */
  const config = {
    transform: {
      // Since `babel-jest` will not do type checking for the test code.
      // We need to manually run `tsc`. Another option is to use `jest-runner-tsc`
      // which currently has certain performance limitation
      // See https://jestjs.io/docs/en/getting-started#using-typescript
      '^.+\\.m?[jt]sx?$': [
        'babel-jest',
        {
          configFile: babelConfigPath,
        },
      ],
    },
    transformIgnorePatterns: TEMPORARY__esmPackagesToTransform.length
      ? [
          // NOTE: Providing regexp patterns that overlap with each other may result in files
          // not being transformed that you expected to be transformed
          // See https://jestjs.io/docs/configuration#transformignorepatterns-arraystring
          `/node_modules/(?!${TEMPORARY__esmPackagesToTransform.join('|')})`,
        ]
      : [],
    // Setup to run immediately after the test framework has been installed in the environment
    // before each test file in the suite is executed
    // See https://jestjs.io/docs/en/configuration#setupfilesafterenv-array
    setupFilesAfterEnv: [],
    moduleNameMapper: {
      // Since for Typescript, we have fully adopted ESM, the imports will contain extensions
      // as such, in the test, since we're not running Jest with ESM support, we will need to
      // strip these extensions.
      // NOTE: we account for package imports like `hash.js`, `fuse.js`, etc.
      // See https://github.com/kulshekhar/ts-jest/issues/1057
      //
      // TODO: problem with ESM - remove when we run Jest with ESM
      // See https://github.com/finos/legend-studio/issues/502
      '^\\.(.+)\\.js': '.$1',
      // Mock for non-javascript file as we don't need Jest to transform these
      // NOTE: we should not need this right now, but we leave this here just in case
      '\\.(svg|css|scss)$': '@finos/legend-dev-utils/mocks/fileMock',
    },
    // Since each test should be independent, we automatically restore mock state before every test
    // NOTE: only works for `jest.spyOn` and not `jest.fn()`
    // See https://jestjs.io/docs/en/configuration#restoremocks-boolean
    restoreMocks: true,
    // Use this pattern (instead of the one from the official doc) to make this work across different OS's
    // See https://github.com/facebook/jest/issues/7914#issuecomment-464352069
    testMatch: ['**/__tests__/**/*(*.)test.[jt]s?(x)'],
    testPathIgnorePatterns: ['/node_modules/'],
    // NOTE: we cannot really turn this flag on, though we have tried to disabled usage of global jest
    // within the code base, some libraries we rely on still need global injections apparently,
    // we observed problems with mock libraries like `jest-canvas-mock`, timing issues, and duplicated
    // rendering of elements in general
    // injectGlobals: false,
  };

  return isGlobal
    ? {
        ...config,
        verbose: true,
        collectCoverage: false,
        watchPathIgnorePatterns: ['/node_modules/'],
        // Allow searching for file/test name while running Jest in watch mode
        watchPlugins: [
          'jest-watch-typeahead/filename',
          'jest-watch-typeahead/testname',
        ],
        reporters: [
          'default',
          // the built-in GitHub Actions Reporter will annotate changed files with test failure messages
          'github-actions',
        ],
      }
    : config;
};