Extract published date from abbreviated and non-ISO formats

[drstarry]

Symptom

Two related bugs when extracting the published date from pages with non-ISO or non-sibling date layouts.

Case 1 — JSON-LD ships non-ISO strings. Some publishers emit schema.org structured data like "datePublished": "Oct 20, 2025" instead of the ISO 8601 format the spec requires. Defuddle returned the raw string, which downstream consumers then passed to new Date() — hitting V8's year-2001 fallback for incomplete date strings (new Date("Oct 20") → 2001-10-20).

Case 2 — Date lives in an h1 cousin subtree. Other pages have no JSON-LD date at all and structure their markup so the date is a descendant of an h1 sibling's sibling, not the h1 itself. Defuddle's existing h1.nextElementSibling walk couldn't reach it and returned empty.

Both patterns show up on live Anthropic pages — the news section hits case 1, the engineering section hits case 2.

Fix

Three complementary changes in src/metadata.ts:

1. parseDateText accepts month abbreviations. Jan, Feb, Sept, Oct, etc. in addition to full month names. A shared MONTH_PATTERN keeps the day-first and month-first regexes in sync.

2. getPublished normalizes all source paths through parseDateText. JSON-LD, meta tags, abbr elements, and time elements now pass through the parser before returning. ISO strings fall through unchanged; natural-language strings get normalized to YYYY-MM-DDT00:00:00+00:00.

3. h1-proximity search walks ancestors. When h1.nextElementSibling finds nothing, the search walks up to three ancestor levels and scans their p and time descendants. This scopes the search to the article header area without scanning the whole document.

// 1. Shared month pattern (abbreviations + full names, optional trailing period)
private static readonly MONTH_PATTERN =
    '(Jan(?:uary)?|Feb(?:ruary)?|Mar(?:ch)?|Apr(?:il)?|May|Jun(?:e)?|Jul(?:y)?|Aug(?:ust)?|Sept?(?:ember)?|Oct(?:ober)?|Nov(?:ember)?|Dec(?:ember)?)\\.?';

// 2. Normalize all getPublished sources
if (result) return this.parseDateText(result) || result;

// 3. Walk h1 ancestors when forward-sibling search fails
let ancestor: Element | null = h1.parentElement;
for (let depth = 0; depth < 3 && ancestor; depth++) {
    for (const child of Array.from(ancestor.querySelectorAll('p, time'))) {
        if (child === h1 || h1.contains(child)) continue;
        const parsed = this.parseDateText(child.textContent?.trim() || '');
        if (parsed) return parsed;
    }
    ancestor = ancestor.parentElement;
}

This PR supersedes #248 — it subsumes the <time> element text parsing fix from that branch and expands it to cover the JSON-LD and cousin-subtree cases that showed up in real Anthropic pages.

Tests

• New unit tests (tests/parse-date-text.test.ts) — 11 cases covering full names, abbreviations, day-of-week prefixes, and ISO fall-through
• New fixture metadata--json-ld-natural-date.html — reproduces the JSON-LD "Oct 20, 2025" pattern
• New fixture metadata--h1-cousin-date.html — reproduces the cousin-subtree layout
• New fixture metadata--time-element-no-datetime.html — (from prior branch commit) reproduces <time>April 8, 2026</time> without a datetime attribute
• Updated expected math--katex.md — "" → "2020-04-29T00:00:00+00:00"; the fixture contains "29 Apr 2020" which the expanded parser now matches. This was previously a silent miss.
• Updated expected general--www.figma.com-blog-introducing-codex-to-figma.md — "February 26, 2026" → "2026-02-26T00:00:00+00:00"; the JSON-LD normalization now converts it. Also previously a silent miss.

All 253 tests pass (11 new parseDateText units + 148 fixtures + 94 other tests).

Before / After

Source	Input	Before	After
JSON-LD	"datePublished": "Oct 20, 2025"	"Oct 20, 2025" (raw)	"2025-10-20T00:00:00+00:00"
<time>	<time>April 8, 2026</time>	"April 8, 2026" (raw)	"2026-04-08T00:00:00+00:00"
h1 cousin	<p class="date">Feb 05, 2026</p> in sibling subtree	"" (empty)	"2026-02-05T00:00:00+00:00"
meta tag	content="February 26, 2026"	"February 26, 2026" (raw)	"2026-02-26T00:00:00+00:00"
ISO string	"2025-01-15"	"2025-01-15"	"2025-01-15" (unchanged)
Unknown	"some unknown format"	"some unknown format"	"some unknown format" (unchanged fallback)

Verified against real pages

• https://www.anthropic.com/news/claude-code-on-the-web — published: "2025-10-20T00:00:00+00:00" ✓
• https://www.anthropic.com/engineering/building-c-compiler — published: "2026-02-05T00:00:00+00:00" ✓