[Content collections] Fix "underscore to ignore" warnings (#6122)

* refactor: fix underscore check

* fix: add "ignore list" to always silence log

* fix: hide log on file deleted

* refactor: move getEntryType to util

* test: getEntryType unit

* fix: handle all unsupported cases

* chore: changeset

5 files changed, 117 insertions, 34 deletions

diff --git a/.changeset/grumpy-bees-worry.md b/.changeset/grumpy-bees-worry.md
new file mode 100644
index 000000000..bab88ad25
--- /dev/null
+++ b/.changeset/grumpy-bees-worry.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Content collections: Fix accidental "use underscore to ignore" logs for `.DS_Store` files and underscored directory names.
diff --git a/packages/astro/src/content/types-generator.ts b/packages/astro/src/content/types-generator.ts
index da0e84dcc..50f8088de 100644
--- a/packages/astro/src/content/types-generator.ts
+++ b/packages/astro/src/content/types-generator.ts
@@ -6,8 +6,8 @@ import { fileURLToPath, pathToFileURL } from 'node:url';
 import { normalizePath, ViteDevServer } from 'vite';
 import type { AstroSettings } from '../@types/astro.js';
 import { info, LogOptions, warn } from '../core/logger/core.js';
-import { appendForwardSlash, isRelativePath } from '../core/path.js';
-import { contentFileExts, CONTENT_TYPES_FILE } from './consts.js';
+import { isRelativePath } from '../core/path.js';
+import { CONTENT_TYPES_FILE } from './consts.js';
 import {
 	ContentConfig,
 	ContentObservable,
@@ -16,6 +16,7 @@ import {
 	getContentPaths,
 	getEntryInfo,
 	getEntrySlug,
+	getEntryType,
 	loadContentConfig,
 	NoCollectionError,
 	parseFrontmatter,
@@ -111,7 +112,7 @@ export async function createContentTypesGenerator({
 			return { shouldGenerateTypes: true };
 		}
 		const fileType = getEntryType(fileURLToPath(event.entry), contentPaths);
-		if (fileType === 'generated-types') {
+		if (fileType === 'ignored') {
 			return { shouldGenerateTypes: false };
 		}
 		if (fileType === 'config') {
@@ -125,22 +126,21 @@ export async function createContentTypesGenerator({
 
 			return { shouldGenerateTypes: true };
 		}
-		if (fileType === 'unknown') {
+		if (fileType === 'unsupported') {
+			// Avoid warning if file was deleted.
+			if (event.name === 'unlink') {
+				return { shouldGenerateTypes: false };
+			}
 			const entryInfo = getEntryInfo({
 				entry: event.entry,
 				contentDir: contentPaths.contentDir,
-				// Allow underscore `_` files outside collection directories
+				// Skip invalid file check. We already know it’s invalid.
 				allowFilesOutsideCollection: true,
 			});
-			if (entryInfo.id.startsWith('_') && (event.name === 'add' || event.name === 'change')) {
-				// Silently ignore `_` files.
-				return { shouldGenerateTypes: false };
-			} else {
-				return {
-					shouldGenerateTypes: false,
-					error: new UnsupportedFileTypeError(entryInfo.id),
-				};
-			}
+			return {
+				shouldGenerateTypes: false,
+				error: new UnsupportedFileTypeError(entryInfo.id),
+			};
 		}
 		const entryInfo = getEntryInfo({
 			entry: event.entry,
@@ -289,23 +289,6 @@ function removeEntry(contentTypes: ContentTypes, collectionKey: string, entryKey
 	delete contentTypes[collectionKey][entryKey];
 }
 
-export function getEntryType(
-	entryPath: string,
-	paths: ContentPaths
-): 'content' | 'config' | 'unknown' | 'generated-types' {
-	const { dir: rawDir, ext, base } = path.parse(entryPath);
-	const dir = appendForwardSlash(pathToFileURL(rawDir).href);
-	if ((contentFileExts as readonly string[]).includes(ext)) {
-		return 'content';
-	} else if (new URL(base, dir).href === paths.config.href) {
-		return 'config';
-	} else if (new URL(base, dir).href === new URL(CONTENT_TYPES_FILE, paths.cacheDir).href) {
-		return 'generated-types';
-	} else {
-		return 'unknown';
-	}
-}
-
 async function writeContentFiles({
 	fs,
 	contentPaths,
diff --git a/packages/astro/src/content/utils.ts b/packages/astro/src/content/utils.ts
index a2c463189..a1ddba757 100644
--- a/packages/astro/src/content/utils.ts
+++ b/packages/astro/src/content/utils.ts
@@ -2,12 +2,13 @@ import { slug as githubSlug } from 'github-slugger';
 import matter from 'gray-matter';
 import type fsMod from 'node:fs';
 import path from 'node:path';
-import { fileURLToPath } from 'node:url';
+import { fileURLToPath, pathToFileURL } from 'node:url';
 import { ErrorPayload as ViteErrorPayload, normalizePath, ViteDevServer } from 'vite';
 import { z } from 'zod';
 import { AstroConfig, AstroSettings } from '../@types/astro.js';
 import { AstroError, AstroErrorData } from '../core/errors/index.js';
-import { CONTENT_TYPES_FILE } from './consts.js';
+import { appendForwardSlash } from '../core/path.js';
+import { contentFileExts, CONTENT_TYPES_FILE } from './consts.js';
 
 export const collectionConfigParser = z.object({
 	schema: z.any().optional(),
@@ -158,6 +159,38 @@ export function getEntryInfo({
 	return res;
 }
 
+export function getEntryType(
+	entryPath: string,
+	paths: Pick<ContentPaths, 'config'>
+): 'content' | 'config' | 'ignored' | 'unsupported' {
+	const { dir: rawDir, ext, base } = path.parse(entryPath);
+	const dir = appendForwardSlash(pathToFileURL(rawDir).href);
+	const fileUrl = new URL(base, dir);
+
+	if (hasUnderscoreInPath(fileUrl) || isOnIgnoreList(fileUrl)) {
+		return 'ignored';
+	} else if ((contentFileExts as readonly string[]).includes(ext)) {
+		return 'content';
+	} else if (fileUrl.href === paths.config.href) {
+		return 'config';
+	} else {
+		return 'unsupported';
+	}
+}
+
+function isOnIgnoreList(fileUrl: URL) {
+	const { base } = path.parse(fileURLToPath(fileUrl));
+	return ['.DS_Store'].includes(base);
+}
+
+function hasUnderscoreInPath(fileUrl: URL): boolean {
+	const parts = fileUrl.pathname.split('/');
+	for (const part of parts) {
+		if (part.startsWith('_')) return true;
+	}
+	return false;
+}
+
 const flattenErrorPath = (errorPath: (string | number)[]) => errorPath.join('.');
 
 const errorMap: z.ZodErrorMap = (error, ctx) => {
diff --git a/packages/astro/src/content/vite-plugin-content-imports.ts b/packages/astro/src/content/vite-plugin-content-imports.ts
index 66d20d703..7c7e8f65c 100644
--- a/packages/astro/src/content/vite-plugin-content-imports.ts
+++ b/packages/astro/src/content/vite-plugin-content-imports.ts
@@ -7,7 +7,7 @@ import { AstroErrorData } from '../core/errors/errors-data.js';
 import { AstroError } from '../core/errors/errors.js';
 import { escapeViteEnvReferences, getFileInfo } from '../vite-plugin-utils/index.js';
 import { contentFileExts, CONTENT_FLAG } from './consts.js';
-import { getEntryType } from './types-generator.js';
+import { getEntryType } from './utils.js';
 import {
 	ContentConfig,
 	getContentPaths,
diff --git a/packages/astro/test/units/content-collections/get-entry-type.test.js b/packages/astro/test/units/content-collections/get-entry-type.test.js
new file mode 100644
index 000000000..3248a88f6
--- /dev/null
+++ b/packages/astro/test/units/content-collections/get-entry-type.test.js
@@ -0,0 +1,62 @@
+import { getEntryType } from '../../../dist/content/utils.js';
+import { expect } from 'chai';
+import { fileURLToPath } from 'node:url';
+
+describe('Content Collections - getEntryType', () => {
+	const contentDir = new URL('src/content/', import.meta.url);
+	const contentPaths = {
+		config: new URL('src/content/config.ts', import.meta.url),
+	};
+
+	it('Returns "content" for Markdown files', () => {
+		for (const entryPath of ['blog/first-post.md', 'blog/first-post.mdx']) {
+			const entry = fileURLToPath(new URL(entryPath, contentDir));
+			const type = getEntryType(entry, contentPaths);
+			expect(type).to.equal('content');
+		}
+	});
+
+	it('Returns "content" for Markdown files in nested directories', () => {
+		for (const entryPath of ['blog/2021/01/01/index.md', 'blog/2021/01/01/index.mdx']) {
+			const entry = fileURLToPath(new URL(entryPath, contentDir));
+			const type = getEntryType(entry, contentPaths);
+			expect(type).to.equal('content');
+		}
+	});
+
+	it('Returns "config" for config files', () => {
+		const entry = fileURLToPath(contentPaths.config);
+		const type = getEntryType(entry, contentPaths);
+		expect(type).to.equal('config');
+	});
+
+	it('Returns "unsupported" for non-Markdown files', () => {
+		const entry = fileURLToPath(new URL('blog/robots.txt', contentDir));
+		const type = getEntryType(entry, contentPaths);
+		expect(type).to.equal('unsupported');
+	});
+
+	it('Returns "ignored" for .DS_Store', () => {
+		const entry = fileURLToPath(new URL('blog/.DS_Store', contentDir));
+		const type = getEntryType(entry, contentPaths);
+		expect(type).to.equal('ignored');
+	});
+
+	it('Returns "ignored" for unsupported files using an underscore', () => {
+		const entry = fileURLToPath(new URL('blog/_draft-robots.txt', contentDir));
+		const type = getEntryType(entry, contentPaths);
+		expect(type).to.equal('ignored');
+	});
+
+	it('Returns "ignored" when using underscore on file name', () => {
+		const entry = fileURLToPath(new URL('blog/_first-post.md', contentDir));
+		const type = getEntryType(entry, contentPaths);
+		expect(type).to.equal('ignored');
+	});
+
+	it('Returns "ignored" when using underscore on directory name', () => {
+		const entry = fileURLToPath(new URL('blog/_draft/first-post.md', contentDir));
+		const type = getEntryType(entry, contentPaths);
+		expect(type).to.equal('ignored');
+	});
+});