await for async jest config

docs/Configuration.md

@@ -18,9 +18,16 @@ Or through JavaScript:
 
 ```js
 // jest.config.js
+//Sync object
 module.exports = {
   verbose: true,
 };
+//Or async function
+module.exports = async () => {
+  return {
+    verbose: true,
+  };
+};
 ```
 
 Please keep in mind that the resulting configuration must be JSON-serializable.

packages/jest-config/package.json

@@ -1,6 +1,6 @@
 {
   "name": "jest-config",
-  "version": "24.9.0",
+  "version": "25.0.0",
   "repository": {
     "type": "git",
     "url": "https://github.com/facebook/jest.git",

packages/jest-config/src/__tests__/readConfig.test.ts

@@ -7,16 +7,15 @@
 
 import {readConfig} from '../index';
 
-test('readConfig() throws when an object is passed without a file path', () => {
-  expect(() => {
-    readConfig(
-      // @ts-ignore
-      null /* argv */,
-      {} /* packageRootOrConfig */,
-      false /* skipArgvConfigOption */,
-      null /* parentConfigPath */,
-    );
-  }).toThrowError(
+test('readConfig() throws when an object is passed without a file path', async () => {
+  // @ts-ignore
+  const asyncConfig = readConfig(
+    null /* argv */,
+    {} /* packageRootOrConfig */,
+    false /* skipArgvConfigOption */,
+    null /* parentConfigPath */,
+  );
+  await expect(asyncConfig).rejects.toThrowError(
     'Jest: Cannot use configuration as an object without a file path',
   );
 });

packages/jest-config/src/__tests__/readConfigs.test.ts

@@ -7,9 +7,10 @@
 
 import {readConfigs} from '../index';
 
-test('readConfigs() throws when called without project paths', () => {
-  expect(() => {
-    // @ts-ignore
-    readConfigs(null /* argv */, [] /* projectPaths */);
-  }).toThrowError('jest: No configuration found for any project.');
+test('readConfigs() throws when called without project paths', async () => {
+  // @ts-ignore
+  const asyncConfig = readConfigs(null /* argv */, [] /* projectPaths */);
+  await expect(asyncConfig).rejects.toThrowError(
+    'jest: No configuration found for any project.',
+  );
 });

packages/jest-config/src/index.ts

@@ -27,7 +27,7 @@ type ReadConfig = {
   projectConfig: Config.ProjectConfig;
 };
 
-export function readConfig(
+export async function readConfig(
   argv: Config.Argv,
   packageRootOrConfig: Config.Path | Config.InitialOptions,
   // Whether it needs to look into `--config` arg passed to CLI.
@@ -37,7 +37,7 @@ export function readConfig(
   skipArgvConfigOption?: boolean,
   parentConfigPath?: Config.Path | null,
   projectIndex: number = Infinity,
-): ReadConfig {
+): Promise<ReadConfig> {
   let rawOptions;
   let configPath = null;
 
@@ -72,11 +72,11 @@ export function readConfig(
     // or a path to directory containing `package.json` or `jest.config.js`
   } else if (!skipArgvConfigOption && typeof argv.config == 'string') {
     configPath = resolveConfigPath(argv.config, process.cwd());
-    rawOptions = readConfigFileAndSetRootDir(configPath);
+    rawOptions = await readConfigFileAndSetRootDir(configPath);
   } else {
     // Otherwise just try to find config in the current rootDir.
     configPath = resolveConfigPath(packageRootOrConfig, process.cwd());
-    rawOptions = readConfigFileAndSetRootDir(configPath);
+    rawOptions = await readConfigFileAndSetRootDir(configPath);
   }
 
   const {options, hasDeprecationWarnings} = normalize(
@@ -260,22 +260,22 @@ This usually means that your ${chalk.bold(
 //
 // If no projects are specified, process.cwd() will be used as the default
 // (and only) project.
-export function readConfigs(
+export async function readConfigs(
   argv: Config.Argv,
   projectPaths: Array<Config.Path>,
-): {
+): Promise<{
   globalConfig: Config.GlobalConfig;
   configs: Array<Config.ProjectConfig>;
   hasDeprecationWarnings: boolean;
-} {
+}> {
   let globalConfig;
   let hasDeprecationWarnings;
   let configs: Array<Config.ProjectConfig> = [];
   let projects = projectPaths;
   let configPath: Config.Path | null | undefined;
 
   if (projectPaths.length === 1) {
-    const parsedConfig = readConfig(argv, projects[0]);
+    const parsedConfig = await readConfig(argv, projects[0]);
     configPath = parsedConfig.configPath;
 
     if (parsedConfig.globalConfig.projects) {
@@ -298,24 +298,26 @@ export function readConfigs(
     projects.length > 1 ||
     (projects.length && typeof projects[0] === 'object')
   ) {
-    const parsedConfigs = projects
-      .filter(root => {
-        // Ignore globbed files that cannot be `require`d.
-        if (
-          typeof root === 'string' &&
-          fs.existsSync(root) &&
-          !fs.lstatSync(root).isDirectory() &&
-          !root.endsWith('.js') &&
-          !root.endsWith('.json')
-        ) {
-          return false;
-        }
+    const parsedConfigs = await Promise.all(
+      projects
+        .filter(root => {
+          // Ignore globbed files that cannot be `require`d.
+          if (
+            typeof root === 'string' &&
+            fs.existsSync(root) &&
+            !fs.lstatSync(root).isDirectory() &&
+            !root.endsWith('.js') &&
+            !root.endsWith('.json')
+          ) {
+            return false;
+          }
 
-        return true;
-      })
-      .map((root, projectIndex) =>
-        readConfig(argv, root, true, configPath, projectIndex),
-      );
+          return true;
+        })
+        .map(async (root, projectIndex) =>
+          readConfig(argv, root, true, configPath, projectIndex),
+        ),
+    );
 
     ensureNoDuplicateConfigs(parsedConfigs, projects);
     configs = parsedConfigs.map(({projectConfig}) => projectConfig);

packages/jest-config/src/readConfigFileAndSetRootDir.ts

@@ -15,7 +15,9 @@ import {PACKAGE_JSON} from './constants';
 // Read the configuration and set its `rootDir`
 // 1. If it's a `package.json` file, we look into its "jest" property
 // 2. For any other file, we just require it.
-export default (configPath: Config.Path): Config.InitialOptions => {
+export default async (
+  configPath: Config.Path,
+): Promise<Config.InitialOptions> => {
   const isJSON = configPath.endsWith('.json');
   let configObject;
 

packages/jest-core/src/cli/index.ts

@@ -49,7 +49,7 @@ export const runCLI = async (
   const outputStream =
     argv.json || argv.useStderr ? process.stderr : process.stdout;
 
-  const {globalConfig, configs, hasDeprecationWarnings} = readConfigs(
+  const {globalConfig, configs, hasDeprecationWarnings} = await readConfigs(
     argv,
     projects,
   );

packages/jest-runtime/src/cli/index.ts

@@ -20,7 +20,7 @@ import {VERSION} from '../version';
 import {Context} from '../types';
 import * as args from './args';
 
-export function run(cliArgv?: Config.Argv, cliInfo?: Array<string>) {
+export async function run(cliArgv?: Config.Argv, cliInfo?: Array<string>) {
   const realFs = require('fs');
   const fs = require('graceful-fs');
   fs.gracefulify(realFs);
@@ -65,7 +65,7 @@ export function run(cliArgv?: Config.Argv, cliInfo?: Array<string>) {
   }
   // TODO: Figure this out
   // @ts-ignore: this might not have the correct arguments
-  const options = readConfig(argv, root);
+  const options = await readConfig(argv, root);
   const globalConfig = options.globalConfig;
   // Always disable automocking in scripts.
   const config: Config.ProjectConfig = {

packages/jest-runtime/src/index.ts

@@ -749,7 +749,7 @@ class Runtime {
         filename,
         localModule.require as LocalModuleRequire,
       ), // jest object
-      ...this._config.extraGlobals.map(globalVariable => {
+      ...(this._config.extraGlobals || []).map(globalVariable => {
         if (this._environment.global[globalVariable]) {
           return this._environment.global[globalVariable];
         }