feat(tools): 2.0 phase 5 wave 3a - video depth (22 tools) (#221)

tests/unit/api/video-speed.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, it } from "vitest";
+import { buildAtempoChain } from "../../../apps/api/src/routes/tools/video-speed.js";
+
+describe("buildAtempoChain", () => {
+  it("returns a single atempo for factor >= 0.5", () => {
+    expect(buildAtempoChain(2)).toBe("atempo=2");
+    expect(buildAtempoChain(0.5)).toBe("atempo=0.5");
+    expect(buildAtempoChain(1)).toBe("atempo=1");
+  });
+
+  it("chains factors of 0.5 for values below 0.5", () => {
+    expect(buildAtempoChain(0.25)).toBe("atempo=0.5,atempo=0.5");
+  });
+
+  it("chains correctly for very small factors", () => {
+    // 0.125 = 0.5 * 0.5 * 0.5
+    expect(buildAtempoChain(0.125)).toBe("atempo=0.5,atempo=0.5,atempo=0.5");
+  });
+});