Fix collections regex (#557)

* fix: :bug: Fixes bug #532

Matching for collection routes should look for exact filename matches

* test: :white_check_mark: Adding test coverage to make sure collection routes are matched exactly

* chore: Adding changeset

4 files changed, 44 insertions, 1 deletions

diff --git a/.changeset/orange-grapes-divide.md b/.changeset/orange-grapes-divide.md
new file mode 100644
index 000000000..1f0f890f5
--- /dev/null
+++ b/.changeset/orange-grapes-divide.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Updates collections to match URLs by exact template filename
diff --git a/packages/astro/src/search.ts b/packages/astro/src/search.ts
index 198ec73b0..ce3a57b95 100644
--- a/packages/astro/src/search.ts
+++ b/packages/astro/src/search.ts
@@ -115,7 +115,7 @@ export function searchForPage(url: URL, astroConfig: AstroConfig): SearchResult
 function loadCollection(url: string, astroConfig: AstroConfig): { currentPage?: number; location: PageLocation } | undefined {
   const pages = glob('**/$*.astro', { cwd: fileURLToPath(astroConfig.pages), filesOnly: true });
   for (const pageURL of pages) {
-    const reqURL = new RegExp('^/' + pageURL.replace(/\$([^/]+)\.astro/, '$1') + '/?(.*)');
+    const reqURL = new RegExp('^/' + pageURL.replace(/\$([^/]+)\.astro/, '$1') + '(?:\/(.*)|\/?$)');
     const match = url.match(reqURL);
     if (match) {
       let currentPage: number | undefined;
diff --git a/packages/astro/test/astro-collection.test.js b/packages/astro/test/astro-collection.test.js
index 058ebbbb6..4f685b355 100644
--- a/packages/astro/test/astro-collection.test.js
+++ b/packages/astro/test/astro-collection.test.js
@@ -109,4 +109,18 @@ Collections('generates individual pages from a collection', async ({ runtime })
   }
 });
 
+Collections('matches collection filename exactly', async ({ runtime }) => {
+  const result = await runtime.load('/individuals');
+  if (result.error) throw new Error(result.error);
+  const $ = doc(result.contents);
+
+  assert.ok($('#posts').length);
+  const urls = [
+    ...$('#posts a').map(function () {
+      return $(this).attr('href');
+    }),
+  ];
+  assert.equal(urls, ['/post/nested/a', '/post/three', '/post/two', '/post/one']);
+});
+
 Collections.run();
diff --git a/packages/astro/test/fixtures/astro-collection/src/pages/$individuals.astro b/packages/astro/test/fixtures/astro-collection/src/pages/$individuals.astro
new file mode 100644
index 000000000..97d5ec206
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-collection/src/pages/$individuals.astro
@@ -0,0 +1,24 @@
+---
+const { collection } = Astro.props;
+
+export async function createCollection() {
+  return {
+    async data() {
+      let data = Astro.fetchContent('./post/**/*.md');
+      data.sort((a, b) => new Date(b.date) - new Date(a.date));
+      return data;
+    },
+
+    pageSize: 10
+  };
+}
+---
+
+<div id="posts">
+{collection.data.map((post) => (
+  <article>
+    <h1>{post.title}</h1>
+    <a href={post.url}>Read more</a>
+  </article>
+))}
+</div>
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