feat(blog): grouped list, pinned posts, author/date/copy-link metadata (#20)

Co-authored-by: Alice <alice@prismshadow.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/landing/test/blog.test.ts

@@ -0,0 +1,111 @@
+import { describe, expect, it } from "vitest";
+import {
+  DEFAULT_AUTHOR,
+  comparePosts,
+  formatAuthors,
+  formatPostDate,
+  getPost,
+  parseAuthors,
+  postsFor,
+} from "../src/lib/blog";
+
+const entry = (pinned: boolean, date: string, slug: string) => ({ pinned, date, slug });
+
+describe("comparePosts", () => {
+  it("sorts pinned first, then date desc, then slug", () => {
+    const sorted = [
+      entry(false, "2026-07-20", "beta"),
+      entry(false, "2026-07-21", "newest"),
+      entry(true, "2026-07-01", "pinned-old"),
+      entry(false, "2026-07-20", "alpha"),
+    ].sort(comparePosts);
+    expect(sorted.map((p) => p.slug)).toEqual(["pinned-old", "newest", "alpha", "beta"]);
+  });
+
+  it("orders two pinned posts by date desc", () => {
+    const sorted = [entry(true, "2026-07-01", "old"), entry(true, "2026-07-20", "new")].sort(
+      comparePosts,
+    );
+    expect(sorted.map((p) => p.slug)).toEqual(["new", "old"]);
+  });
+});
+
+describe("formatPostDate", () => {
+  it("formats en dates as long US dates", () => {
+    expect(formatPostDate("2026-06-18", "en")).toBe("June 18, 2026");
+    expect(formatPostDate("2026-07-20", "en")).toBe("July 20, 2026");
+  });
+
+  it("formats zh dates as 年月日", () => {
+    expect(formatPostDate("2026-06-18", "zh")).toBe("2026年6月18日");
+    expect(formatPostDate("2026-07-20", "zh")).toBe("2026年7月20日");
+  });
+
+  it("interprets the date in UTC so the calendar day never shifts", () => {
+    // 2026-01-01 rendered in a western timezone would show Dec 31 without UTC pinning.
+    expect(formatPostDate("2026-01-01", "en")).toBe("January 1, 2026");
+  });
+
+  it("falls back to the raw string for unexpected input", () => {
+    expect(formatPostDate("", "en")).toBe("");
+    expect(formatPostDate("not-a-date", "zh")).toBe("not-a-date");
+  });
+
+  it("falls back to the raw string for impossible calendar dates", () => {
+    expect(formatPostDate("2026-02-31", "en")).toBe("2026-02-31");
+    expect(formatPostDate("2026-13-01", "en")).toBe("2026-13-01");
+    expect(formatPostDate("2026-04-00", "zh")).toBe("2026-04-00");
+  });
+});
+
+describe("parseAuthors / formatAuthors", () => {
+  it("splits comma-class separators and trims", () => {
+    expect(parseAuthors("A (AMD), B（X）、C ，D")).toEqual(["A (AMD)", "B（X）", "C", "D"]);
+  });
+
+  it("falls back to the default byline when absent or blank", () => {
+    expect(parseAuthors(undefined)).toEqual([DEFAULT_AUTHOR]);
+    expect(parseAuthors("  ")).toEqual([DEFAULT_AUTHOR]);
+  });
+
+  it("joins with a comma in English and 顿号 in Chinese", () => {
+    expect(formatAuthors(["A", "B"], "en")).toBe("A, B");
+    expect(formatAuthors(["甲", "乙"], "zh")).toBe("甲、乙");
+    expect(formatAuthors(["A"], "en")).toBe("A");
+  });
+});
+
+describe("frontmatter mapping (author / pinned / category)", () => {
+  it("defaults authors and pinned when the frontmatter omits them", () => {
+    const post = getPost("july-2026-updates", "en");
+    expect(post?.authors).toEqual([DEFAULT_AUTHOR]);
+    expect(post?.pinned).toBe(false);
+  });
+
+  it("reads the explicit author list and the practice category", () => {
+    const post = getPost("local-agents-on-amd-gpus", "en");
+    expect(post?.authors).toEqual([
+      "Ning Zhang (AMD)",
+      "Yuyang Gao (AMD)",
+      "Yaowei Zheng (PrismShadow)",
+    ]);
+    expect(post?.category).toBe("practice");
+    expect(post?.pinned).toBe(false);
+  });
+
+  it("reads the pinned flag and sorts the pinned post first", () => {
+    for (const locale of ["en", "zh"] as const) {
+      const posts = postsFor(locale);
+      expect(posts.length).toBe(5);
+      expect(posts[0]?.slug).toBe("introducing-penguinharness");
+      expect(posts[0]?.pinned).toBe(true);
+    }
+  });
+
+  it("filters by the practice category, newest first", () => {
+    expect(postsFor("en", "practice").map((p) => p.slug)).toEqual([
+      "penguin-harness-self-improvement-with-amd-gpu",
+      "local-agents-on-amd-gpus",
+    ]);
+  });
+});