refactor: extract backend

src/backend/esbuild/eval.ts

@@ -0,0 +1,8 @@
+export const createEsbuildEvalTransformSync = (esbuild: typeof import('esbuild')) => (evalCode: string, inputType?: string) => esbuild.transformSync(
+	evalCode,
+	{
+		loader: 'default',
+		sourcefile: '/eval.ts',
+		format: inputType === 'module' ? 'esm' : 'cjs',
+	},
+).code;

src/backend/esbuild/index.ts

@@ -0,0 +1,12 @@
+import type { TransformOptions } from 'esbuild';
+import type { Backend } from '..';
+import { createEsbuildEvalTransformSync } from './eval';
+import { createEsbuildReplTransform } from './repl';
+import { createEsbuildTransformSync, createEsbuildTransform } from './transform';
+
+const getEsbuildBackend = (esbuild: typeof import('esbuild')): Backend<TransformOptions> => ({
+	evalTransformSync: createEsbuildEvalTransformSync(esbuild),
+	replTransform: createEsbuildReplTransform(esbuild),
+	transformSync: createEsbuildTransformSync(esbuild),
+	transform: createEsbuildTransform(esbuild),
+}); export default getEsbuildBackend;

src/backend/esbuild/repl.ts

@@ -0,0 +1,15 @@
+export const createEsbuildReplTransform = (esbuild: typeof import('esbuild')) => async (code: string, filename: string): Promise<string> => esbuild.transform(
+	code,
+	{
+		sourcefile: filename,
+		loader: 'ts',
+		tsconfigRaw: {
+			compilerOptions: {
+				preserveValueImports: true,
+			},
+		},
+		define: {
+			require: 'global.require',
+		},
+	},
+).then(result => result.code);

src/utils/transform/index.ts → src/backend/esbuild/transform.ts

@@ -1,22 +1,19 @@
 import { pathToFileURL } from 'node:url';
 import {
-	transform as esbuildTransform,
-	transformSync as esbuildTransformSync,
-	version as esbuildVersion,
 	type TransformOptions,
 	type TransformFailure,
 } from 'esbuild';
-import { sha1 } from '../sha1.js';
+import { sha1 } from '../../utils/sha1.js';
 import {
 	version as transformDynamicImportVersion,
 	transformDynamicImport,
-} from './transform-dynamic-import.js';
-import cache from './cache.js';
+} from '../../utils/transform/transform-dynamic-import.js';
+import cache from '../../utils/transform/cache.js';
 import {
 	applyTransformersSync,
 	applyTransformers,
 	type Transformed,
-} from './apply-transformers.js';
+} from '../../utils/transform/apply-transformers.js';
 import {
 	cacheConfig,
 	patchOptions,
@@ -33,8 +30,8 @@ const formatEsbuildError = (
 	throw error;
 };
 
-// Used by cjs-loader
-export const transformSync = (
+// used by cjs-loader
+export const createEsbuildTransformSync = (esbuild: typeof import('esbuild')) => (
 	code: string,
 	filePath: string,
 	extendOptions?: TransformOptions,
@@ -63,7 +60,7 @@ export const transformSync = (
 	const hash = sha1([
 		code,
 		JSON.stringify(esbuildOptions),
-		esbuildVersion,
+		esbuild.version,
 		transformDynamicImportVersion,
 	].join('-'));
 	let transformed = cache.get(hash);
@@ -77,7 +74,7 @@ export const transformSync = (
 					const patchResult = patchOptions(esbuildOptions);
 					let result;
 					try {
-						result = esbuildTransformSync(_code, esbuildOptions);
+						result = esbuild.transformSync(_code, esbuildOptions);
 					} catch (error) {
 						throw formatEsbuildError(error as TransformFailure);
 					}
@@ -94,7 +91,7 @@ export const transformSync = (
 };
 
 // Used by esm-loader
-export const transform = async (
+export const createEsbuildTransform = (esbuild: typeof import('esbuild')) => async (
 	code: string,
 	filePath: string,
 	extendOptions?: TransformOptions,
@@ -109,7 +106,7 @@ export const transform = async (
 	const hash = sha1([
 		code,
 		JSON.stringify(esbuildOptions),
-		esbuildVersion,
+		esbuild.version,
 		transformDynamicImportVersion,
 	].join('-'));
 	let transformed = cache.get(hash);
@@ -123,7 +120,7 @@ export const transform = async (
 					const patchResult = patchOptions(esbuildOptions);
 					let result;
 					try {
-						result = await esbuildTransform(_code, esbuildOptions);
+						result = await esbuild.transform(_code, esbuildOptions);
 					} catch (error) {
 						throw formatEsbuildError(error as TransformFailure);
 					}

src/backend/index.ts

@@ -0,0 +1,23 @@
+import esbuild from 'esbuild';
+import type { Transformed } from '../utils/transform/apply-transformers';
+
+import getEsbuildBackend from './esbuild';
+
+export interface Backend<ExtendedTransformOptions> {
+	evalTransformSync: (evalCode: string, inputType?: string) => string;
+	replTransform: (code: string, filename: string) => Promise<string>;
+	transformSync: (
+		code: string,
+		filePath: string,
+		extendOptions?: ExtendedTransformOptions,
+	) => Transformed;
+	transform: (
+		code: string,
+		filePath: string,
+		extendOptions?: ExtendedTransformOptions,
+	) => Promise<Transformed>;
+}
+
+const backend = getEsbuildBackend(esbuild);
+
+export default backend;

src/cjs/api/module-extensions.ts

@@ -2,7 +2,7 @@ import fs from 'node:fs';
 import path from 'node:path';
 import Module from 'node:module';
 import type { TransformOptions } from 'esbuild';
-import { transformSync } from '../../utils/transform/index.js';
+import backend from '../../backend/index.js';
 import { transformDynamicImport } from '../../utils/transform/transform-dynamic-import.js';
 import { isESM } from '../../utils/es-module-lexer.js';
 import { shouldApplySourceMap, inlineSourceMap } from '../../source-map.js';
@@ -140,7 +140,7 @@ export const createExtensions = (
 			// CommonJS file but uses ESM import/export
 			|| isESM(code)
 		) {
-			const transformed = transformSync(
+			const transformed = backend.transformSync(
 				code,
 				filePath,
 				{

src/cli.ts

@@ -2,9 +2,6 @@ import { constants as osConstants } from 'node:os';
 import type { ChildProcess, Serializable } from 'node:child_process';
 import type { Server } from 'node:net';
 import { cli } from 'cleye';
-import {
-	transformSync as esbuildTransformSync,
-} from 'esbuild';
 import { version } from '../package.json';
 import { run } from './run.js';
 import { watchCommand } from './watch/index.js';
@@ -14,6 +11,7 @@ import {
 } from './remove-argv-flags.js';
 import { isFeatureSupported, testRunnerGlob } from './utils/node-features.js';
 import { createIpcServer } from './utils/ipc/server.js';
+import backend from './backend';
 
 // const debug = (...messages: any[]) => {
 // 	if (process.env.DEBUG) {
@@ -206,16 +204,12 @@ cli({
 	if (evalType) {
 		const { inputType } = interceptedFlags;
 		const evalCode = interceptedFlags[evalType]!;
-		const transformed = esbuildTransformSync(
+		const transformed = backend.evalTransformSync(
 			evalCode,
-			{
-				loader: 'default',
-				sourcefile: '/eval.ts',
-				format: inputType === 'module' ? 'esm' : 'cjs',
-			},
+			inputType,
 		);
 
-		argvsToRun.unshift(`--${evalType}`, transformed.code);
+		argvsToRun.unshift(`--${evalType}`, transformed);
 	}
 
 	// Default --test glob to find TypeScript files

src/esm/hook/load.ts

@@ -1,9 +1,9 @@
 import { fileURLToPath } from 'node:url';
 import path from 'node:path';
-import type { LoadHook } from 'node:module';
+import type { LoadHook, LoadHookContext } from 'node:module';
 import { readFile } from 'node:fs/promises';
 import type { TransformOptions } from 'esbuild';
-import { transform, transformSync } from '../../utils/transform/index.js';
+import backend from '../../backend/index.js';
 import { transformDynamicImport } from '../../utils/transform/transform-dynamic-import.js';
 import { inlineSourceMap } from '../../source-map.js';
 import { isFeatureSupported, importAttributes, esmLoadReadFile } from '../../utils/node-features.js';
@@ -56,11 +56,10 @@ export const load: LoadHook = async (
 	}
 
 	if (isJsonPattern.test(url)) {
-		if (!context[contextAttributesProperty]) {
-			context[contextAttributesProperty] = {};
-		}
-
-		context[contextAttributesProperty]!.type = 'json';
+		// @types/node only declares `importAttributes` type
+		// eslint-disable-next-line @typescript-eslint/no-explicit-any
+		context[contextAttributesProperty as keyof LoadHookContext] ||= {} as any;
+		(context[contextAttributesProperty as keyof LoadHookContext] as ImportAttributes).type = 'json';
 	}
 
 	const loaded = await nextLoad(url, context);
@@ -91,7 +90,7 @@ export const load: LoadHook = async (
 			 * which are already in CJS syntax.
 			 * In CTS, module.exports can be written in any pattern.
 			 */
-			const transformed = transformSync(
+			const transformed = backend.transformSync(
 				code,
 				filePath,
 				{
@@ -118,7 +117,7 @@ export const load: LoadHook = async (
 		loaded.format === 'json'
 		|| tsExtensionsPattern.test(url)
 	) {
-		const transformed = await transform(
+		const transformed = await backend.transform(
 			code,
 			filePath,
 			{

src/patch-repl.ts

@@ -1,27 +1,11 @@
 import repl, { type REPLServer, type REPLEval } from 'node:repl';
-import { transform } from 'esbuild';
+import backend from './backend';
 
 const patchEval = (nodeRepl: REPLServer) => {
 	const { eval: defaultEval } = nodeRepl;
 	const preEval: REPLEval = async function (code, context, filename, callback) {
 		try {
-			const transformed = await transform(
-				code,
-				{
-					sourcefile: filename,
-					loader: 'ts',
-					tsconfigRaw: {
-						compilerOptions: {
-							preserveValueImports: true,
-						},
-					},
-					define: {
-						require: 'global.require',
-					},
-				},
-			);
-
-			code = transformed.code;
+			code = await backend.replTransform(code, filename);
 		} catch {}
 
 		return defaultEval.call(this, code, context, filename, callback);

src/repl.ts

@@ -2,7 +2,7 @@
 
 import repl, { type REPLEval } from 'node:repl';
 import { version } from '../package.json';
-import { transform } from './utils/transform/index.js';
+import backend from './backend/index.js';
 
 // Copied from
 // https://github.com/nodejs/node/blob/v18.2.0/lib/internal/main/repl.js#L37
@@ -16,7 +16,7 @@ const nodeRepl = repl.start();
 const { eval: defaultEval } = nodeRepl;
 
 const preEval: REPLEval = async function (code, context, filename, callback) {
-	const transformed = await transform(
+	const transformed = await backend.transform(
 		code,
 		filename,
 		{

tests/index.ts

@@ -5,7 +5,7 @@ import { nodeVersions } from './utils/node-versions';
 (async () => {
 	await describe('tsx', async ({ runTestSuite, describe }) => {
 		await runTestSuite(import('./specs/repl'));
-		await runTestSuite(import('./specs/transform'));
+		await runTestSuite(import('./specs/transform-esbuild'));
 
 		for (const nodeVersion of nodeVersions) {
 			const node = await createNode(nodeVersion);

tests/specs/transform.ts → tests/specs/transform-esbuild.ts

@@ -2,7 +2,10 @@ import { testSuite, expect } from 'manten';
 import { createFsRequire } from 'fs-require';
 import { Volume } from 'memfs';
 import outdent from 'outdent';
-import { transform, transformSync } from '../../src/utils/transform/index.js';
+import esbuild from 'esbuild';
+import getEsbuildBackend from '../../src/backend/esbuild/index.js';
+
+const backend = getEsbuildBackend(esbuild);
 
 const base64Module = (code: string) => `data:text/javascript;base64,${Buffer.from(code).toString('base64')}`;
 
@@ -41,7 +44,7 @@ export default testSuite(({ describe }) => {
 	describe('transform', ({ describe }) => {
 		describe('sync', ({ test }) => {
 			test('transforms ESM to CJS', () => {
-				const transformed = transformSync(
+				const transformed = backend.transformSync(
 					fixtures.esm,
 					'file.js',
 					{ format: 'cjs' },
@@ -64,7 +67,7 @@ export default testSuite(({ describe }) => {
 			});
 
 			test('dynamic import', () => {
-				const dynamicImport = transformSync(
+				const dynamicImport = backend.transformSync(
 					'import((0, _url.pathToFileURL)(path).href)',
 					'file.js',
 					{ format: 'cjs' },
@@ -75,7 +78,7 @@ export default testSuite(({ describe }) => {
 
 			test('sourcemap file', () => {
 				const fileName = 'file.mts';
-				const transformed = transformSync(
+				const transformed = backend.transformSync(
 					fixtures.ts,
 					fileName,
 					{ format: 'esm' },
@@ -93,7 +96,7 @@ export default testSuite(({ describe }) => {
 
 			test('quotes in file path', () => {
 				const fileName = '\'"name.mts';
-				const transformed = transformSync(
+				const transformed = backend.transformSync(
 					fixtures.ts,
 					fileName,
 					{ format: 'esm' },
@@ -112,7 +115,7 @@ export default testSuite(({ describe }) => {
 
 		describe('async', ({ test }) => {
 			test('transforms TS to ESM', async () => {
-				const transformed = await transform(
+				const transformed = await backend.transform(
 					fixtures.ts,
 					'file.ts',
 					{ format: 'esm' },
@@ -133,7 +136,7 @@ export default testSuite(({ describe }) => {
 
 			test('sourcemap file', async () => {
 				const fileName = 'file.cts';
-				const transformed = await transform(
+				const transformed = await backend.transform(
 					fixtures.ts,
 					fileName,
 					{ format: 'esm' },