test: add coverage for formatRelativeTimeAgo and formatLogMetadata (#94)

These two exported functions in src/utils/format.ts had no test
coverage. formatRelativeTimeAgo wraps formatRelativeTime and forces
numeric:'always' for past dates; formatLogMetadata assembles parts
(time, branch, size/count, tag, agentSetting, prNumber) into a
' · '-separated string.

Added 8 tests for formatRelativeTimeAgo covering past dates, future
dates, equal-to-now, and the no-'ago'-for-future invariant. Added
9 tests for formatLogMetadata covering all optional fields and the
separator format.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

src/utils/__tests__/format.test.ts

@@ -6,6 +6,8 @@ import {
   formatNumber,
   formatTokens,
   formatRelativeTime,
+  formatRelativeTimeAgo,
+  formatLogMetadata,
 } from "../format";
 
 describe("formatFileSize", () => {
@@ -153,3 +155,144 @@ describe("formatRelativeTime", () => {
     expect(formatRelativeTime(date, { now })).toBe("2w ago");
   });
 });
+
+describe("formatRelativeTimeAgo", () => {
+  const now = new Date("2026-01-15T12:00:00Z");
+
+  test("formats past date with 'ago' suffix", () => {
+    const date = new Date("2026-01-15T11:59:30Z");
+    const result = formatRelativeTimeAgo(date, { now });
+    expect(result).toBe("30s ago");
+  });
+
+  test("formats future date without 'ago' suffix", () => {
+    const date = new Date("2026-01-15T13:00:00Z");
+    const result = formatRelativeTimeAgo(date, { now });
+    expect(result).toBe("in 1h");
+  });
+
+  test("formats minutes ago", () => {
+    const date = new Date("2026-01-15T11:55:00Z");
+    const result = formatRelativeTimeAgo(date, { now });
+    expect(result).toBe("5m ago");
+  });
+
+  test("formats hours ago", () => {
+    const date = new Date("2026-01-15T09:00:00Z");
+    const result = formatRelativeTimeAgo(date, { now });
+    expect(result).toBe("3h ago");
+  });
+
+  test("formats days ago", () => {
+    const date = new Date("2026-01-13T12:00:00Z");
+    const result = formatRelativeTimeAgo(date, { now });
+    expect(result).toBe("2d ago");
+  });
+
+  test("handles date equal to now as past", () => {
+    // date === now, treated as past (not future)
+    const result = formatRelativeTimeAgo(now, { now });
+    expect(result).toBe("0s ago");
+  });
+
+  test("uses numeric always for past dates", () => {
+    // Should always use numeric format for past dates
+    const date = new Date("2026-01-15T11:59:00Z");
+    const result = formatRelativeTimeAgo(date, { now });
+    expect(result).toContain("ago");
+  });
+
+  test("future date does not contain 'ago'", () => {
+    const date = new Date("2026-01-15T14:00:00Z");
+    const result = formatRelativeTimeAgo(date, { now });
+    expect(result).not.toContain("ago");
+  });
+});
+
+describe("formatLogMetadata", () => {
+  // Use a date very recently in the past so it always shows "Xs ago" or similar
+  const modified = new Date(Date.now() - 5 * 60 * 1000); // 5 minutes ago
+
+  test("includes relative time and message count", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 10,
+    });
+    expect(result).toContain("ago");
+    expect(result).toContain("10 messages");
+  });
+
+  test("uses fileSize instead of messageCount when provided", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 5,
+      fileSize: 1536,
+    });
+    expect(result).toContain("1.5KB");
+    expect(result).not.toContain("messages");
+  });
+
+  test("includes gitBranch when provided", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 3,
+      gitBranch: "main",
+    });
+    expect(result).toContain("main");
+  });
+
+  test("omits gitBranch when not provided", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 3,
+    });
+    // Should not have a dangling separator from missing branch
+    expect(result).not.toMatch(/^ · | · $/);
+  });
+
+  test("includes tag when provided", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 3,
+      tag: "my-tag",
+    });
+    expect(result).toContain("#my-tag");
+  });
+
+  test("includes agentSetting when provided", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 3,
+      agentSetting: "custom-agent",
+    });
+    expect(result).toContain("@custom-agent");
+  });
+
+  test("includes prNumber when provided", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 3,
+      prNumber: 42,
+    });
+    expect(result).toContain("#42");
+  });
+
+  test("includes prRepository with prNumber when both provided", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 3,
+      prNumber: 99,
+      prRepository: "owner/repo",
+    });
+    expect(result).toContain("owner/repo#99");
+  });
+
+  test("parts are joined with ' · ' separator", () => {
+    const result = formatLogMetadata({
+      modified,
+      messageCount: 5,
+      gitBranch: "feat/x",
+    });
+    expect(result).toContain(" · ");
+  });
+});