1 files changed, 31 insertions, 0 deletions
diff --git a/apps/web/src/lib/retime/__tests__/split.test.ts b/apps/web/src/lib/retime/__tests__/split.test.ts
new file mode 100644
index 00000000..0ce532a1
--- /dev/null
+++ b/apps/web/src/lib/retime/__tests__/split.test.ts
@@ -0,0 +1,31 @@
+import { describe, expect, test } from "bun:test";
+import {
+	getSourceSpanAtClipTime,
+	splitRetimeAtClipTime,
+} from "@/lib/retime";
+import type { RetimeConfig } from "@/lib/timeline";
+
+describe("retime split", () => {
+	test("measures source span at a clip time", () => {
+		const retime: RetimeConfig = { rate: 2 };
+		expect(getSourceSpanAtClipTime({ clipTime: 5, retime })).toBe(10);
+	});
+
+	test("returns zero for non-positive clip time", () => {
+		expect(getSourceSpanAtClipTime({ clipTime: 0 })).toBe(0);
+		expect(getSourceSpanAtClipTime({ clipTime: -1 })).toBe(0);
+	});
+
+	test("passes the same retime to both halves when splitting", () => {
+		const retime: RetimeConfig = { rate: 1.5 };
+		const result = splitRetimeAtClipTime({ retime, splitClipTime: 3 });
+		expect(result.left).toBe(retime);
+		expect(result.right).toBe(retime);
+	});
+
+	test("returns undefined on both sides when no retime", () => {
+		const result = splitRetimeAtClipTime({ splitClipTime: 3 });
+		expect(result.left).toBeUndefined();
+		expect(result.right).toBeUndefined();
+	});
+});