fix: V8 coverage support

closes #433

Author: privatenumber

src/utils/transform/get-esbuild-options.ts

@@ -16,12 +16,12 @@ export const cacheConfig = {
 	sourcemap: true,
 
 	/**
-	 * Improve performance by generating smaller source maps
-	 * that doesn't include the original source code
+	 * Improve performance by only generating sourcesContent
+	 * when V8 coverage is enabled
 	 *
 	 * https://esbuild.github.io/api/#sources-content
 	 */
-	sourcesContent: false,
+	sourcesContent: Boolean(process.env.NODE_V8_COVERAGE),
 
 	/**
 	 * Smaller output for cache and marginal performance improvement:

tests/specs/smoke.ts

@@ -4,6 +4,7 @@ import { testSuite, expect } from 'manten';
 import { createFixture } from 'fs-fixture';
 import outdent from 'outdent';
 import type { NodeApis } from '../utils/tsx.js';
+import { hasCoverageSourcesContent } from '../utils/coverage-sources-content.js';
 
 const cjsContextCheck = 'typeof module !== \'undefined\'';
 const tsCheck = '1 as number';
@@ -352,7 +353,6 @@ export default testSuite(async ({ describe }, { tsx }: NodeApis) => {
 			describe(packageType, ({ test, describe }) => {
 				test('from .js', async ({ onTestFinish, onTestFail }) => {
 					const fixture = await createFixture({
-						...files,
 						'package.json': JSON.stringify({ type: packageType }),
 						'import-from-js.js': outdent`
 						import assert from 'assert';
@@ -459,7 +459,8 @@ export default testSuite(async ({ describe }, { tsx }: NodeApis) => {
 						// Could .js import TS files?
 
 						// Comment at EOF: could be a sourcemap declaration. Edge case for inserting functions here
-						`.trim(),
+						`,
+						...files,
 					});
 					onTestFinish(async () => await fixture.rm());
 
@@ -488,7 +489,6 @@ export default testSuite(async ({ describe }, { tsx }: NodeApis) => {
 
 				describe('from .ts', async ({ test, onFinish }) => {
 					const fixture = await createFixture({
-						...files,
 						'package.json': JSON.stringify({ type: packageType }),
 
 						'import-from-ts.ts': ({ fixturePath }) => outdent`
@@ -652,12 +652,18 @@ export default testSuite(async ({ describe }, { tsx }: NodeApis) => {
 						}));
 
 						// Comment at EOF: could be a sourcemap declaration. Edge case for inserting functions here
-						`.trim(),
+						`,
+						...files,
 					});
 					onFinish(async () => await fixture.rm());
 
 					test('import all', async ({ onTestFail }) => {
-						const p = await tsx(['import-from-ts.ts'], fixture.path);
+						const p = await tsx(['import-from-ts.ts'], {
+							cwd: fixture.path,
+							env: {
+								NODE_V8_COVERAGE: 'coverage',
+							},
+						});
 						onTestFail((error) => {
 							console.error(error);
 							console.log(p);
@@ -678,6 +684,10 @@ export default testSuite(async ({ describe }, { tsx }: NodeApis) => {
 						// By "require()"ing an ESM file, it forces it to be compiled in a CJS context
 						expect(p.stdout).toMatch(`"mjs":{"mjsHasCjsContext":${isCommonJs}}`);
 						expect(p.stderr).toBe('');
+
+						const coverageDirectory = fixture.getPath('coverage');
+						const coverageSourceMapCache = await hasCoverageSourcesContent(coverageDirectory);
+						expect(coverageSourceMapCache).toBe(true);
 					});
 
 					test('tsconfig', async ({ onTestFail }) => {

tests/utils/coverage-sources-content.ts

@@ -0,0 +1,28 @@
+import path from 'node:path';
+import fs from 'node:fs/promises';
+
+type SourceMapCache = Record<string, {
+	data: {
+		sourcesContent: string[];
+	} | null;
+}>;
+
+export const hasCoverageSourcesContent = async (
+	coverageDirectory: string,
+) => {
+	const fileNames = await fs.readdir(coverageDirectory);
+	const coverageData = await Promise.all(
+		fileNames.map(
+			async file => JSON.parse(
+				await fs.readFile(path.join(coverageDirectory, file), 'utf8'),
+			),
+		),
+	);
+	return coverageData.some(coverage => (
+		coverage['source-map-cache']
+		&& (
+			Object.values(coverage['source-map-cache'] as SourceMapCache)
+				.some(value => typeof value.data?.sourcesContent?.[0] === 'string')
+		)
+	));
+};

tests/utils/tsx.ts

@@ -67,25 +67,33 @@ export const createNode = async (
 		tsx: (
 			args: string[],
 			cwdOrOptions?: string | NodeOptions,
-		) => execaNode(
-			tsxPath,
-			args,
-			{
-				env: {
-					TSX_DISABLE_CACHE: '1',
-					DEBUG: '1',
+		) => {
+			const isCwd = typeof cwdOrOptions === 'string';
+			return execaNode(
+				tsxPath,
+				args,
+				{
+					nodePath: node.path,
+					nodeOptions: [],
+					reject: false,
+					all: true,
+					...(
+						isCwd
+							? { cwd: cwdOrOptions }
+							: cwdOrOptions
+					),
+					env: {
+						TSX_DISABLE_CACHE: '1',
+						DEBUG: '1',
+						...(
+							(cwdOrOptions && !isCwd)
+								? cwdOrOptions.env
+								: {}
+						),
+					},
 				},
-				nodePath: node.path,
-				nodeOptions: [],
-				reject: false,
-				all: true,
-				...(
-					typeof cwdOrOptions === 'string'
-						? { cwd: cwdOrOptions }
-						: cwdOrOptions
-				),
-			},
-		),
+			);
+		},
 
 		cjsPatched: (
 			args: string[],