fix(content): ensure underscore ignores only child paths of the content directory. (#6330)

* test: add test fixture

* test: add cc config file

* migrate to unit test instead

* fix: only include child folders in ignore list

* chore: changeset

3 files changed, 81 insertions, 54 deletions

diff --git a/.changeset/tiny-geckos-reply.md b/.changeset/tiny-geckos-reply.md
new file mode 100644
index 000000000..c9b7917d0
--- /dev/null
+++ b/.changeset/tiny-geckos-reply.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Ensure prefixed underscore ignores only child paths of the content directory.
diff --git a/packages/astro/src/content/utils.ts b/packages/astro/src/content/utils.ts
index 70771f2dc..afe15eeb0 100644
--- a/packages/astro/src/content/utils.ts
+++ b/packages/astro/src/content/utils.ts
@@ -160,12 +160,12 @@ export function getEntryInfo({
 
 export function getEntryType(
 	entryPath: string,
-	paths: Pick<ContentPaths, 'config'>
+	paths: Pick<ContentPaths, 'config' | 'contentDir'>
 ): 'content' | 'config' | 'ignored' | 'unsupported' {
 	const { ext, base } = path.parse(entryPath);
 	const fileUrl = pathToFileURL(entryPath);
 
-	if (hasUnderscoreInPath(fileUrl) || isOnIgnoreList(base)) {
+	if (hasUnderscoreBelowContentDirectoryPath(fileUrl, paths.contentDir) || isOnIgnoreList(base)) {
 		return 'ignored';
 	} else if ((contentFileExts as readonly string[]).includes(ext)) {
 		return 'content';
@@ -180,8 +180,11 @@ function isOnIgnoreList(fileName: string) {
 	return ['.DS_Store'].includes(fileName);
 }
 
-function hasUnderscoreInPath(fileUrl: URL): boolean {
-	const parts = fileUrl.pathname.split('/');
+function hasUnderscoreBelowContentDirectoryPath(
+	fileUrl: URL,
+	contentDir: ContentPaths['contentDir']
+): boolean {
+	const parts = fileUrl.pathname.replace(contentDir.pathname, '').split('/');
 	for (const part of parts) {
 		if (part.startsWith('_')) return true;
 	}
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
index b9293d22d..3e549c2a2 100644
--- a/packages/astro/test/units/content-collections/get-entry-type.test.js
+++ b/packages/astro/test/units/content-collections/get-entry-type.test.js
@@ -2,64 +2,83 @@ 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: {
-			url: new URL('src/content/config.ts', import.meta.url),
-			exists: true,
+const fixtures = [
+	{
+		title: 'Without any underscore above the content directory tree',
+		contentPaths: {
+			config: {
+				url: new URL('src/content/config.ts', import.meta.url),
+				exists: true,
+			},
+			contentDir: new URL('src/content/', import.meta.url),
+		},
+	},
+	{
+		title: 'With underscore levels above the content directory tree',
+		contentPaths: {
+			config: {
+				url: new URL('_src/content/config.ts', import.meta.url),
+				exists: true,
+			},
+			contentDir: new URL('_src/content/', 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');
-		}
-	});
+describe('Content Collections - getEntryType', () => {
+	fixtures.forEach(({ title, contentPaths }) => {
+		describe(title, () => {
+			it('Returns "content" for Markdown files', () => {
+				for (const entryPath of ['blog/first-post.md', 'blog/first-post.mdx']) {
+					const entry = fileURLToPath(new URL(entryPath, contentPaths.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 "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, contentPaths.contentDir));
+					const type = getEntryType(entry, contentPaths);
+					expect(type).to.equal('content');
+				}
+			});
 
-	it('Returns "config" for config files', () => {
-		const entry = fileURLToPath(contentPaths.config.url);
-		const type = getEntryType(entry, contentPaths);
-		expect(type).to.equal('config');
-	});
+			it('Returns "config" for config files', () => {
+				const entry = fileURLToPath(contentPaths.config.url);
+				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 "unsupported" for non-Markdown files', () => {
+				const entry = fileURLToPath(new URL('blog/robots.txt', contentPaths.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 .DS_Store', () => {
+				const entry = fileURLToPath(new URL('blog/.DS_Store', contentPaths.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" for unsupported files using an underscore', () => {
+				const entry = fileURLToPath(new URL('blog/_draft-robots.txt', contentPaths.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 file name', () => {
+				const entry = fileURLToPath(new URL('blog/_first-post.md', contentPaths.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');
+			it('Returns "ignored" when using underscore on directory name', () => {
+				const entry = fileURLToPath(new URL('blog/_draft/first-post.md', contentPaths.contentDir));
+				const type = getEntryType(entry, contentPaths);
+				expect(type).to.equal('ignored');
+			});
+		});
 	});
 });