Coerce YAML Date frontmatter to a date string

packages/framework/src/content.test.ts

@@ -0,0 +1,57 @@
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { afterEach, beforeEach, describe, expect, it } from 'vitest';
+import { loadBlogPosts, loadChangelogEntries } from './content';
+
+let tmpRoot: string;
+let prevContentRoot: string | undefined;
+
+beforeEach(() => {
+  tmpRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'inkform-content-test-'));
+  prevContentRoot = process.env.DOCS_CONTENT_ROOT;
+  process.env.DOCS_CONTENT_ROOT = tmpRoot;
+});
+
+afterEach(() => {
+  fs.rmSync(tmpRoot, { recursive: true, force: true });
+  if (prevContentRoot === undefined) delete process.env.DOCS_CONTENT_ROOT;
+  else process.env.DOCS_CONTENT_ROOT = prevContentRoot;
+});
+
+function writeMdx(dir: string, file: string, frontmatter: string, body = 'Body.') {
+  fs.mkdirSync(dir, { recursive: true });
+  fs.writeFileSync(path.join(dir, file), `---\n${frontmatter}\n---\n${body}\n`);
+}
+
+describe('loadBlogPosts date parsing', () => {
+  it('reads an unquoted YAML date (parsed as a Date, not a string)', () => {
+    const blogDir = path.join(tmpRoot, 'blog');
+    writeMdx(blogDir, 'unquoted.mdx', 'title: Unquoted\ndate: 2026-01-25\nstatus: published');
+    writeMdx(blogDir, 'quoted.mdx', "title: Quoted\ndate: '2026-01-20'\nstatus: published");
+
+    const posts = loadBlogPosts();
+    const bySlug = new Map(posts.map((p) => [p.slug, p]));
+
+    expect(bySlug.get('unquoted')?.date).toBe('2026-01-25');
+    expect(bySlug.get('quoted')?.date).toBe('2026-01-20');
+    // Newest first — regression check for the '' sorting-last bug.
+    expect(posts.map((p) => p.slug)).toEqual(['unquoted', 'quoted']);
+  });
+
+  it('falls back to an empty string for a genuinely missing date', () => {
+    const blogDir = path.join(tmpRoot, 'blog');
+    writeMdx(blogDir, 'no-date.mdx', 'title: No date\nstatus: published');
+    const posts = loadBlogPosts();
+    expect(posts[0].date).toBe('');
+  });
+});
+
+describe('loadChangelogEntries date parsing', () => {
+  it('reads an unquoted YAML date the same way as blog posts', () => {
+    const changelogDir = path.join(tmpRoot, 'changelog');
+    writeMdx(changelogDir, '2026-02-10-v2.mdx', 'title: v2\ndate: 2026-02-10\nstatus: published');
+    const entries = loadChangelogEntries();
+    expect(entries[0].date).toBe('2026-02-10');
+  });
+});

packages/framework/src/content.ts

@@ -56,6 +56,19 @@ export function readingTimeMinutes(content: string): number {
   return Math.max(1, Math.round(words / 200));
 }
 
+/**
+ * Frontmatter `date` as `YYYY-MM-DD`. YAML parses an unquoted date like
+ * `date: 2026-01-25` as a `Date` at UTC midnight, not a string — gray-matter
+ * passes that through as-is, so a plain `typeof === 'string'` check drops it
+ * to `''` (sorts last, renders "Invalid Date"). Read it off the `Date` in UTC
+ * so the day doesn't shift for authors west of UTC.
+ */
+function toDateString(v: unknown): string {
+  if (typeof v === 'string') return v.slice(0, 10);
+  if (v instanceof Date && !Number.isNaN(v.getTime())) return v.toISOString().slice(0, 10);
+  return '';
+}
+
 function plainExcerpt(content: string, max = 200): string {
   const text = content
     .replace(/^---[\s\S]*?---/, '')
@@ -91,7 +104,7 @@ function toBlogPost(fileSlug: string, data: Record<string, unknown>, content: st
   return {
     slug: str(data.slug) ?? fileSlug,
     title: str(data.title) ?? 'Untitled',
-    date: typeof data.date === 'string' ? data.date.slice(0, 10) : '',
+    date: toDateString(data.date),
     author: str(data.author),
     tags: Array.isArray(data.tags) ? (data.tags.filter((t) => typeof t === 'string') as string[]) : [],
     status: str(data.status) ?? 'published',
@@ -166,7 +179,7 @@ export function loadChangelogEntries(dir = 'changelog', includeDrafts = false):
       if (!parsed) return null;
       const d = parsed.data;
       const str = (v: unknown) => (typeof v === 'string' && v.trim() ? v : null);
-      const date = typeof d.date === 'string' ? d.date.slice(0, 10) : '';
+      const date = toDateString(d.date);
       const status = str(d.status) ?? 'published';
       return {
         slug: f.replace(/\.mdx$/, '').replace(/^\d{4}-\d{2}-\d{2}-/, ''),