fix(jest): Let jest keep using CommonJS

ESM is barely supported in Jest atm, pending stabilization of VM modules in node.js

This keeps transpiling to CommonJS for Jest's sake

Author: nikolaik

.eslintrc.cjs

@@ -1,7 +1,7 @@
 module.exports = {
   parser: '@typescript-eslint/parser', // Specifies the ESLint parser
   parserOptions: {
-    ecmaVersion: "latest", // Allows for the parsing of modern ECMAScript features
+    ecmaVersion: 'latest', // Allows for the parsing of modern ECMAScript features
     sourceType: 'module', // Allows for the use of imports
   },
   extends: [

.nvmrc

@@ -1 +1 @@
-20.15.0
+20.16.0

Dockerfile

@@ -5,4 +5,4 @@ COPY package.json package-lock.json ./
 RUN npm install --production
 COPY . .
 
-CMD cd /app && npm start 
+CMD ["npm", "start"]

babel.config.cjs

@@ -1,4 +1,4 @@
 module.exports = {
-    presets: [["@babel/preset-env", { targets: { node: "current" } }], "@babel/preset-typescript"],
-    plugins: ["babel-plugin-transform-import-meta"],
-  }
+  presets: [['@babel/preset-env', { targets: { node: 'current' } }], '@babel/preset-typescript'],
+  plugins: ['babel-plugin-transform-import-meta'],
+}

index.ts

@@ -1,6 +1,6 @@
-import { getGithubUsersFromGoogle } from './src/google'
-import { getGithubUsersFromGithub, addUsersToGitHubOrg, removeUsersFromGitHubOrg } from './src/github'
-import { config } from './src/config'
+import { getGithubUsersFromGoogle } from './src/google.js'
+import { getGithubUsersFromGithub, addUsersToGitHubOrg, removeUsersFromGitHubOrg } from './src/github.js'
+import { config } from './src/config.js'
 
 export async function run(): Promise<void> {
   const googleUsers = await getGithubUsersFromGoogle()

jest.config.cjs

@@ -1,12 +1,12 @@
+// This project uses ESM at runtime. Since ESM is very much unsupported in jest for now, we have to transform ESM things to CJS format
+// Jest is transforming own code using the babel-jest and we need to do the same for third party ESM code
+// If you add any third party ESM only modules from npm, be sure to add them here:
+const ESM_MODULES = ['@octokit/.*', 'before-after-hook', 'universal-github-app-jwt', 'universal-user-agent']
+
 module.exports = {
-  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$',
-  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
-  testEnvironment: 'node',
   coverageReporters: ['lcovonly', 'text'],
   collectCoverage: true,
   coverageDirectory: 'coverage',
-  restoreMocks: true,
-  resetMocks: true,
   collectCoverageFrom: [
     '**/*.ts',
     '**/*.js',
@@ -16,4 +16,13 @@ module.exports = {
     '!coverage/**',
     '!jest.config.js',
   ],
+  moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1',
+  },
+  restoreMocks: true,
+  resetMocks: true,
+  testEnvironment: 'node',
+  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$',
+  transformIgnorePatterns: [`/node_modules/(?!(${ESM_MODULES.join('|')})/)`],
 }