fix: apply tsconfig only to matching files (#310)

BREAKING CHANGE: `tsconfig.json` is now only applied to files it matches (via `include`/`exclude`/`files`)

package.json

@@ -49,7 +49,7 @@
 	},
 	"dependencies": {
 		"esbuild": "^0.16.17",
-		"get-tsconfig": "^4.3.0",
+		"get-tsconfig": "github:privatenumber/get-tsconfig#npm/file-matcher",
 		"loader-utils": "^2.0.0",
 		"tapable": "^2.2.0",
 		"webpack-sources": "^1.4.3"
@@ -70,7 +70,7 @@
 		"memfs": "^3.4.13",
 		"mini-css-extract-plugin": "^1.6.2",
 		"pkgroll": "^1.8.0",
-		"tsx": "^3.12.2",
+		"tsx": "github:esbuild-kit/tsx#npm/ts-file-matcher",
 		"typescript": "^4.9.4",
 		"webpack": "^4.44.2",
 		"webpack-cli": "^4.10.0",

src/loader.ts

@@ -1,8 +1,11 @@
-import { transform as defaultEsbuildTransform } from 'esbuild';
+import {
+	transform as defaultEsbuildTransform,
+	type TransformOptions,
+} from 'esbuild';
 import { getOptions } from 'loader-utils';
 import webpack from 'webpack';
 import type { LoaderOptions } from './types.js';
-import { tsconfig } from './tsconfig.js';
+import { fileMatcher } from './tsconfig.js';
 
 async function ESBuildLoader(
 	this: webpack.loader.LoaderContext,
@@ -35,7 +38,7 @@ async function ESBuildLoader(
 	};
 
 	if (!('tsconfigRaw' in transformOptions)) {
-		transformOptions.tsconfigRaw = tsconfig;
+		transformOptions.tsconfigRaw = fileMatcher?.(this.resourcePath) as TransformOptions['tsconfigRaw'];
 	}
 
 	try {

src/plugin.ts

@@ -8,7 +8,6 @@ import webpack5 from 'webpack5';
 import { matchObject } from 'webpack/lib/ModuleFilenameHelpers.js';
 import { version } from '../package.json';
 import type { EsbuildPluginOptions } from './types.js';
-import { tsconfig } from './tsconfig.js';
 
 type Compiler = webpack4.Compiler | webpack5.Compiler;
 type Compilation = webpack4.compilation.Compilation | webpack5.Compilation;
@@ -137,10 +136,6 @@ export default function EsbuildPlugin(
 		options.minify = true;
 	}
 
-	if (!('tsconfigRaw' in options)) {
-		options.tsconfigRaw = tsconfig;
-	}
-
 	return {
 		apply(compiler: Compiler) {
 			if (!('format' in options)) {

src/tsconfig.ts

@@ -1,6 +1,11 @@
-import { getTsconfig } from 'get-tsconfig';
+import {
+	getTsconfig,
+	createFilesMatcher,
+} from 'get-tsconfig';
 import type { TransformOptions } from 'esbuild';
 
 const foundTsconfig = getTsconfig();
 
 export const tsconfig = foundTsconfig?.config as (TransformOptions['tsconfigRaw'] | undefined);
+
+export const fileMatcher = foundTsconfig && createFilesMatcher(foundTsconfig);

tests/specs/tsconfig.ts

@@ -1,18 +1,27 @@
 import path from 'path';
+import { createRequire } from 'node:module';
 import { testSuite, expect } from 'manten';
 import { createFixture } from 'fs-fixture';
 import { execa } from 'execa';
 
 const webpackCli = path.resolve('node_modules/webpack-cli/bin/cli.js');
 const esbuildLoader = path.resolve('dist/index.cjs');
 
+const detectStrictMode = `
+(function (isStrict) {
+    arguments[0] = false;
+    return isStrict;
+})(true)
+`;
+
 export default testSuite(({ describe }) => {
 	describe('tsconfig', ({ describe }) => {
 		describe('loader', ({ test }) => {
 			test('finds tsconfig.json and applies strict mode', async () => {
 				const fixture = await createFixture({
 					src: {
-						'index.ts': 'console.log(1)',
+						'index.ts': `module.exports = [${detectStrictMode}, require("./strict.ts")];`,
+						'strict.ts': `module.exports = ${detectStrictMode}`,
 					},
 					'webpack.config.js': `
 					module.exports = {
@@ -36,28 +45,41 @@ export default testSuite(({ describe }) => {
 						},
 	
 						entry: './src/index.ts',
+
+						output: {
+							libraryTarget: 'commonjs2',
+						},
 					};
 					`,
 					'tsconfig.json': JSON.stringify({
 						compilerOptions: {
 							strict: true,
 						},
+						include: [
+							'src/strict.ts',
+						],
 					}),
 				});
 
 				await execa(webpackCli, {
 					cwd: fixture.path,
 				});
 
-				const code = await fixture.readFile('dist/main.js', 'utf8');
-				expect(code).toMatch('use strict');
+				const require = createRequire(import.meta.url);
+				expect(
+					require(path.join(fixture.path, 'dist/main.js')),
+				).toStrictEqual([false, true]);
 
 				await fixture.rm();
 			});
 		});
 
 		describe('plugin', ({ test }) => {
-			test('finds tsconfig.json and applies strict mode', async () => {
+			/**
+			 * Since the plugin applies on distribution assets, it should not apply
+			 * any tsconfig settings.
+			 */
+			test('should not detect tsconfig.json and apply strict mode', async () => {
 				const fixture = await createFixture({
 					src: {
 						'index.js': 'console.log(1)',
@@ -86,7 +108,7 @@ export default testSuite(({ describe }) => {
 				});
 
 				const code = await fixture.readFile('dist/main.js', 'utf8');
-				expect(code).toMatch('use strict');
+				expect(code).not.toMatch('use strict');
 
 				await fixture.rm();
 			});