From b683018be30d1cbafb1f598e809cff4023472187 Mon Sep 17 00:00:00 2001
From: Florian Lefebvre <contact@florian-lefebvre.dev>
Date: Sat, 24 Aug 2024 17:13:01 +0200
Subject: [PATCH] feat: excludeOutDir

---
 packages/astro/src/core/config/schema.ts    |  7 ++++++
 packages/astro/src/core/sync/write-files.ts | 12 ++++++-----
 packages/astro/src/types/public/config.ts   | 24 +++++++++++++++++++++
 packages/astro/test/typescript.test.js      | 18 ++++++++++++++--
 4 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/packages/astro/src/core/config/schema.ts b/packages/astro/src/core/config/schema.ts
index 7cab519f4a..fe9885ab3a 100644
--- a/packages/astro/src/core/config/schema.ts
+++ b/packages/astro/src/core/config/schema.ts
@@ -95,6 +95,9 @@ export const ASTRO_CONFIG_DEFAULTS = {
 		serverIslands: false,
 		contentIntellisense: false,
 		contentLayer: false,
+		typescript: {
+			excludeOutDir: true,
+		},
 	},
 } satisfies AstroUserConfig & { server: { open: boolean } };
 
@@ -544,6 +547,10 @@ export const AstroConfigSchema = z.object({
 				.object({
 					include: z.array(z.string()).optional(),
 					exclude: z.array(z.string()).optional(),
+					excludeOutDir: z
+						.boolean()
+						.optional()
+						.default(ASTRO_CONFIG_DEFAULTS.experimental.typescript.excludeOutDir),
 				})
 				.optional(),
 		})
diff --git a/packages/astro/src/core/sync/write-files.ts b/packages/astro/src/core/sync/write-files.ts
index ba82058e7e..90730cea10 100644
--- a/packages/astro/src/core/sync/write-files.ts
+++ b/packages/astro/src/core/sync/write-files.ts
@@ -82,6 +82,8 @@ async function setupEnvDts(settings: AstroSettings, fs: typeof fsMod, logger: Lo
 }
 
 async function setupTsconfig(settings: AstroSettings, fs: typeof fsMod, logger: Logger) {
+	const typescript = settings.config.experimental.typescript!;
+
 	const tsconfigPath = normalizePath(fileURLToPath(new URL('tsconfig.json', settings.dotAstroDir)));
 	let relativeDtsPath = normalizePath(
 		relative(
@@ -97,8 +99,8 @@ async function setupTsconfig(settings: AstroSettings, fs: typeof fsMod, logger:
 	);
 
 	const include = [relativeDtsPath];
-	if (settings.config.experimental.typescript?.include) {
-		for (const value of settings.config.experimental.typescript.include) {
+	if (typescript.include) {
+		for (const value of typescript.include) {
 			if (startsWithDotSlash(value) || startsWithDotDotSlash(value)) {
 				include.push(
 					normalizePath(
@@ -113,9 +115,9 @@ async function setupTsconfig(settings: AstroSettings, fs: typeof fsMod, logger:
 			}
 		}
 	}
-	const exclude = [relativeOutDirPath];
-	if (settings.config.experimental.typescript?.exclude) {
-		for (const value of settings.config.experimental.typescript.exclude) {
+	const exclude = typescript.excludeOutDir ? [relativeOutDirPath] : [];
+	if (typescript.exclude) {
+		for (const value of typescript.exclude) {
 			if (startsWithDotSlash(value) || startsWithDotDotSlash(value)) {
 				exclude.push(
 					normalizePath(
diff --git a/packages/astro/src/types/public/config.ts b/packages/astro/src/types/public/config.ts
index f494672214..11028d1676 100644
--- a/packages/astro/src/types/public/config.ts
+++ b/packages/astro/src/types/public/config.ts
@@ -2067,6 +2067,30 @@ export interface AstroUserConfig {
 			 * ```
 			 */
 			exclude?: Array<string>;
+
+			/**
+			 * @docs
+			 * @name experimental.typescript.excludeOutDir
+			 * @type {boolean}
+			 * @default `true`
+			 * @version 5.0.0
+			 * @description
+			 *
+			 * By default, `outDir` will be added to excluded typescript files. You can opt-out of this behavior by setting this option to `false`:
+			 *
+			 * ```js title="astro.config.*" ins={6}
+			 * import { defineConfig } from 'astro/config'
+			 *
+			 * export default defineConfig({
+			 *   experimental: {
+			 *    typescript: {
+			 *      excludeOutDir: false
+			 *    }
+			 *   }
+			 * })
+			 * ```
+			 */
+			excludeOutDir?: boolean;
 		};
 	};
 }
diff --git a/packages/astro/test/typescript.test.js b/packages/astro/test/typescript.test.js
index 69019d1252..e2642d920c 100644
--- a/packages/astro/test/typescript.test.js
+++ b/packages/astro/test/typescript.test.js
@@ -126,15 +126,29 @@ describe('experimental.typescript', () => {
 		}
 	});
 
-	it('should add outDir to .astro/tsconfig.json', async () => {
+	it('should add outDir to .astro/tsconfig.json if excludeOutDir is enabled', async () => {
 		for (const outDir of ['dist', 'custom']) {
 			const fixture = await createFixture({ experimental: { typescript: {} }, outDir });
 			await fixture.sync();
-			const tsconfig = JSON.parse(await fixture.readFile(GENERATED_TSCONFIG_PATH));
+			const raw = await fixture.readFile(GENERATED_TSCONFIG_PATH);
+			const tsconfig = JSON.parse(raw);
 			assert.equal(tsconfig.exclude.includes(`../${outDir}`), true);
 		}
 	});
 
+	it('should not add outDir to .astro/tsconfig.json if excludeOutDir is disabled', async () => {
+		for (const outDir of ['dist', 'custom']) {
+			const fixture = await createFixture({
+				experimental: { typescript: { excludeOutDir: false } },
+				outDir,
+			});
+			await fixture.sync();
+			const raw = await fixture.readFile(GENERATED_TSCONFIG_PATH);
+			const tsconfig = JSON.parse(raw);
+			assert.equal(tsconfig.exclude.includes(`../${outDir}`), false);
+		}
+	});
+
 	it('should handle include/exclude relative paths', async () => {
 		const dirs = [
 			{ outDir: 'dist', exclude: '../dist' },