feat: metafile support, jestConfig transformation

BREAKING CHANGE: new bundles are using @swc/jest

Author: noomorph

__fixtures__/simple-project/.esbuild-jestrc.js

@@ -1,12 +1,13 @@
 /** @type {import('esbuild-jest-cli').ESBuildJestConfig} */
 module.exports = {
-  "esbuild": {
-    "sourcemap": true,
-    "platform": "node",
-    "outdir": "../simple-project-bundled",
-    "external": ["chalk", "dtrace-provider", "@linked-dependencies/external"],
+  esbuild: {
+    sourcemap: true,
+    platform: "node",
+    metafile: true,
+    outdir: "../simple-project-bundled",
+    external: ["chalk", "dtrace-provider", "@linked-dependencies/external"],
   },
-  "useTransformer": ({ build, transformer }) => {
+  useTransformer: ({ build, transformer }) => {
     build.onLoad({ filter: /lodash\/noop/ }, async (args) => {
       const fs = await import('fs');
       const raw = await fs.promises.readFile(args.path, 'utf8');
@@ -18,9 +19,14 @@ module.exports = {
       };
     });
   },
-  "package": {
-    "name": "custom-name",
-    "dependencies": {
+  jestConfig: {
+    transform: {
+      'someCuriousPattern': '@swc/jest',
+    },
+  },
+  package: {
+    name: "custom-name",
+    dependencies: {
       "@linked-dependencies/external": "../linked-dependencies/external",
     }
   }

__fixtures__/simple-project/jest.config.js

@@ -11,6 +11,7 @@ module.exports = {
   ],
   testMatch: [
     '<rootDir>/src/**/*.test.js',
+    '<rootDir>/src/**/*.test.cjs',
   ],
   testEnvironment: 'jest-environment-emit/node',
 };

__fixtures__/simple-project/src/entry2.test.js renamed to __fixtures__/simple-project/src/entry2.test.cjs

@@ -1,17 +1,18 @@
 import type { PluginBuild, BuildOptions } from 'esbuild';
+import type { Config as JestConfig } from '@jest/types';
 import type { ScriptTransformer } from '@jest/transform';
 
 export type ESBuildJestConfig = {
   esbuild: Omit<
     BuildOptions,
     | 'bundle'
     | 'splitting'
-    | 'metafile'
     | 'outbase'
     | 'banner'
     | 'format'
     | 'entryPoints'
   >;
+  jestConfig: JestConfig.InitialOptions | ((base: JestConfig.InitialOptions) => JestConfig.InitialOptions);
   package: Record<string, unknown> | ((base: Record<string, unknown>) => Record<string, unknown>);
   useTransformer: (context: { build: PluginBuild; transformer: ScriptTransformer; }) => void | Promise<void>;
   postTransform: (filePath: string, fileContent: string) => string;

index.d.mts

@@ -96,7 +96,9 @@ export async function build(esbuildJestConfig = {}) {
         globalConfig,
         projectConfig,
         tests: tests.map(t => t.path),
-        package: wrapPackageMiddleware(esbuildJestConfig.package),
+        jestConfig: wrapPatcherMiddleware(esbuildJestConfig.jestConfig),
+        package: wrapPatcherMiddleware(esbuildJestConfig.package),
+        writeMetafile: esbuildBaseConfig.metafile,
         useTransformer: esbuildJestConfig.useTransformer,
       }),
       ...(esbuildBaseConfig.plugins || []),
@@ -108,7 +110,7 @@ export async function build(esbuildJestConfig = {}) {
   return buildResult;
 }
 
-function wrapPackageMiddleware(config) {
+function wrapPatcherMiddleware(config) {
   return typeof config === 'function' ? config : createPackageMerger(config)
 }
 

index.mjs

@@ -1,13 +1,13 @@
-import { writeFile } from 'node:fs/promises';
-import { sep, join, relative, resolve } from 'node:path';
+import {writeFile} from 'node:fs/promises';
+import {join, resolve, sep} from 'node:path';
 import importFrom from 'import-from';
-import { logger, optimizeTracing } from "./utils/logger.mjs";
-import { convertPathToImport } from "./utils/resolve-module.mjs";
-import { isBuiltinReporter } from "./utils/is-builtin-reporter.mjs";
-import { mapSourceToOutputFiles } from "./utils/map-inputs-outputs.mjs";
-import { moveJsFile } from "./utils/move-js-file.mjs";
-import { pruneDirectory } from "./utils/prune-directory.mjs";
-import { JEST_DEPENDENCIES } from "./utils/jest-dependencies.mjs";
+import {logger, optimizeTracing} from "./utils/logger.mjs";
+import {convertPathToImport} from "./utils/resolve-module.mjs";
+import {isBuiltinReporter} from "./utils/is-builtin-reporter.mjs";
+import {mapSourceToOutputFiles, relativizeEntries} from "./utils/map-inputs-outputs.mjs";
+import {moveJsFile} from "./utils/move-js-file.mjs";
+import {pruneDirectory} from "./utils/prune-directory.mjs";
+import {JEST_DEPENDENCIES} from "./utils/jest-dependencies.mjs";
 
 const noop = () => {};
 
@@ -24,11 +24,13 @@ const __JEST_CONFIG = (log, config) => __CONTENT(log, config, 'create jest confi
 const __PACKAGE_JSON = (log, packageJson) => __CONTENT(log, packageJson, 'create package.json');
 
 export default ({
+  jestConfig: jestConfigMiddleware,
   package: packageMiddleware,
   globalConfig,
   projectConfig,
   tests,
   useTransformer = noop,
+  writeMetafile = false,
 }) => {
   return {
     name: 'jest',
@@ -55,7 +57,46 @@ export default ({
 
         __FILE_MAPPING_CREATING(logger, mappingInput);
         const mapping = mapSourceToOutputFiles(mappingInput);
+        await moveExternalEntryPointsBackToRoot(mapping);
+        await pruneDirectory(join(outdir, 'node_modules'));
         __FILE_MAPPING_CREATED(logger, mapping);
+        const flattenedConfig = jestConfigMiddleware({
+          maxWorkers: globalConfig.maxWorkers,
+          testTimeout: globalConfig.testTimeout,
+          reporters: globalConfig.reporters.map(mapReporter),
+
+          ...projectConfig,
+          cacheDirectory: undefined,
+          cwd: undefined,
+          coverageDirectory: mapFile(projectConfig.coverageDirectory),
+          globalSetup: mapFile(projectConfig.globalSetup),
+          globalTeardown: mapFile(projectConfig.globalTeardown),
+          id: undefined,
+          moduleNameMapper: undefined,
+          rootDir: undefined,
+          roots: undefined,
+          runner: undefined,
+          setupFiles: projectConfig.setupFiles.map(mapFile),
+          setupFilesAfterEnv: projectConfig.setupFilesAfterEnv.map(mapFile),
+          testEnvironment: mapFile(projectConfig.testEnvironment),
+          testMatch: tests.map(mapFile),
+          testRunner: mapTestRunner(mapFile(projectConfig.testRunner)),
+          transform: {
+            '^(?!node_modules/).+\\.js$': '@swc/jest',
+            '^.+\\.jsx$': '@swc/jest',
+            '^.+\\.tsx?$': '@swc/jest',
+          },
+          transformIgnorePatterns: [],
+        });
+        __JEST_CONFIG(logger, flattenedConfig);
+        await writeFile(join(outdir, 'jest.config.json'), JSON.stringify(flattenedConfig, null, 2));
+
+        if (writeMetafile) {
+          await writeFile(join(outdir, 'metafile.json'), JSON.stringify({
+            ...result.metafile,
+            mapping: relativizeEntries([rootDir, outdir], mapping),
+          }, null, 2) + '\n');
+        }
 
         /**
          * @param {string} file
@@ -125,37 +166,6 @@ export default ({
           const segments = modulePath.split(sep);
           return segments.map(x => x === 'node_modules' && replacements++ === 0 ? 'bundled_modules' : x).join(sep);
         }
-
-        await moveExternalEntryPointsBackToRoot();
-        await pruneDirectory(join(outdir, 'node_modules'));
-
-        const flattenedConfig = {
-          maxWorkers: globalConfig.maxWorkers,
-          testTimeout: globalConfig.testTimeout,
-          reporters: globalConfig.reporters.map(mapReporter),
-
-          ...projectConfig,
-          cacheDirectory: undefined,
-          cwd: undefined,
-          coverageDirectory: mapFile(projectConfig.coverageDirectory),
-          globalSetup: mapFile(projectConfig.globalSetup),
-          globalTeardown: mapFile(projectConfig.globalTeardown),
-          id: undefined,
-          moduleNameMapper: undefined,
-          rootDir: undefined,
-          roots: undefined,
-          runner: undefined,
-          setupFiles: projectConfig.setupFiles.map(mapFile),
-          setupFilesAfterEnv: projectConfig.setupFilesAfterEnv.map(mapFile),
-          testEnvironment: mapFile(projectConfig.testEnvironment),
-          testMatch: tests.map(mapFile),
-          testRunner: mapTestRunner(mapFile(projectConfig.testRunner)),
-          transform: undefined,
-          transformIgnorePatterns: undefined,
-        };
-
-        __JEST_CONFIG(logger, flattenedConfig);
-        await writeFile(join(outdir, 'jest.config.json'), JSON.stringify(flattenedConfig, null, 2));
       });
 
       build.onEnd(async (result) => {
@@ -175,12 +185,12 @@ export default ({
           version: '0.0.0',
           private: true,
           scripts: {
-            test: "NODE_OPTIONS='-r @babel/register' jest"
+            test: "NODE_OPTIONS='-r @swc-node/register' jest"
           },
           dependencies: {
-            "@babel/core": "^7.24.6",
-            "@babel/plugin-transform-modules-commonjs": "^7.24.6",
-            "@babel/register": "^7.24.6",
+            "@swc/core": "^1.10.1",
+            "@swc/jest": "^0.2.37",
+            "@swc-node/register": "^1.10.9",
 
             ...externalDependencies,
           },

plugin.mjs

@@ -29,12 +29,20 @@ export function mapSourceToOutputFiles({ rootDir, outdir, sourceFiles, outputFil
   return result;
 }
 
+export function relativizeEntries(rootDirs, mapping) {
+  return Object.fromEntries(
+    Object.entries(mapping).map(([source, output]) => [
+      path.relative(rootDirs[0], source),
+      path.relative(rootDirs[1], output),
+    ]),
+  );
+}
+
 function adaptTwoDots(filePath) {
   const segments = filePath.split(path.sep);
   return segments.map(convertTwoDots).join(path.sep);
 }
 
 function convertTwoDots(segment) {
   return segment === '_.._' ? '..' : segment;
-
 }