feat(tools): 2.0 phase 5 wave 5b - ai pool: ocr-pdf, transcription, background composites (5 tools) (#226)

tests/unit/api/subtitle-format.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, it } from "vitest";
+import type { TranscriptSegment } from "../../../apps/api/src/lib/subtitle-format.js";
+import { toSrt, toVtt } from "../../../apps/api/src/lib/subtitle-format.js";
+
+const TWO_SEGMENTS: TranscriptSegment[] = [
+  { startS: 0, endS: 1.5, text: "Hello world" },
+  { startS: 2.0, endS: 4.75, text: "Second line" },
+];
+
+describe("toSrt", () => {
+  it("formats two segments with comma millisecond separator and 1-based counters", () => {
+    const result = toSrt(TWO_SEGMENTS);
+    const expected =
+      "1\n00:00:00,000 --> 00:00:01,500\nHello world\n\n" +
+      "2\n00:00:02,000 --> 00:00:04,750\nSecond line\n";
+    expect(result).toBe(expected);
+  });
+
+  it("returns empty string for empty segments", () => {
+    expect(toSrt([])).toBe("");
+  });
+});
+
+describe("toVtt", () => {
+  it("formats two segments with WEBVTT header and dot millisecond separator", () => {
+    const result = toVtt(TWO_SEGMENTS);
+    const expected =
+      "WEBVTT\n\n" +
+      "00:00:00.000 --> 00:00:01.500\nHello world\n\n" +
+      "00:00:02.000 --> 00:00:04.750\nSecond line\n";
+    expect(result).toBe(expected);
+  });
+
+  it("returns WEBVTT header with trailing newlines for empty segments", () => {
+    expect(toVtt([])).toBe("WEBVTT\n\n");
+  });
+});