Open exam PDFs in new tabs

astro.config.mjs

@@ -4,6 +4,7 @@ import { unified } from '@astrojs/markdown-remark';
 import { sidebar } from './src/config/sidebar.mjs';
 import { legacyBachelorRedirects } from './src/config/legacy-bachelor-redirects.mjs';
 import { baseAwareLinks } from './src/config/base-aware-markdown.mjs';
+import { openExamLinksInNewTab } from './src/config/open-exam-links.mjs';
 
 const site = process.env.SITE || 'http://localhost:4321';
 const base = process.env.BASE || '/';
@@ -17,7 +18,12 @@ export default defineConfig({
   base,
   redirects: Object.fromEntries(Object.entries(legacyBachelorRedirects).map(([from, to]) => [from, `${normalizedBase}${to}`])),
   markdown: {
-    processor: unified({ remarkPlugins: [[baseAwareLinks, { base }]] }),
+    processor: unified({
+      remarkPlugins: [
+        [baseAwareLinks, { base }],
+        openExamLinksInNewTab,
+      ],
+    }),
   },
   integrations: [
     starlight({

src/config/open-exam-links.mjs

@@ -0,0 +1,24 @@
+const examArchivePath = /(?:^|[/\\])previous-exams-and-documents\.md$/;
+
+export function openExamLinksInNewTab() {
+  return (tree, file) => {
+    if (!examArchivePath.test(file?.path ?? '')) return;
+
+    const visit = (node) => {
+      if (node.type === 'link' && /\.pdf(?:[?#]|$)/i.test(node.url ?? '')) {
+        node.data = {
+          ...node.data,
+          hProperties: {
+            ...node.data?.hProperties,
+            target: '_blank',
+            rel: 'noopener noreferrer',
+          },
+        };
+      }
+
+      for (const child of node.children ?? []) visit(child);
+    };
+
+    visit(tree);
+  };
+}

tests/open-exam-links.test.mjs

@@ -0,0 +1,35 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { openExamLinksInNewTab } from '../src/config/open-exam-links.mjs';
+
+test('opens PDF links from the exam archive in a new tab', () => {
+  const tree = {
+    type: 'root',
+    children: [
+      { type: 'link', url: '/media/exam.pdf', children: [] },
+      { type: 'link', url: '/computer-science/', children: [] },
+    ],
+  };
+
+  openExamLinksInNewTab()(tree, {
+    path: '/project/src/content/docs/previous-exams-and-documents.md',
+  });
+
+  assert.deepEqual(tree.children[0].data, {
+    hProperties: {
+      target: '_blank',
+      rel: 'noopener noreferrer',
+    },
+  });
+  assert.equal(tree.children[1].data, undefined);
+});
+
+test('leaves PDF links on other pages unchanged', () => {
+  const link = { type: 'link', url: '/media/notes.pdf', children: [] };
+
+  openExamLinksInNewTab()({ type: 'root', children: [link] }, {
+    path: '/project/src/content/docs/course.md',
+  });
+
+  assert.equal(link.data, undefined);
+});