test(editor): expand auto clip guard coverage

src/components/video-editor/types.test.ts

@@ -25,7 +25,7 @@ describe("extendAutoFullTrackClip", () => {
 		).toBeNull();
 	});
 
-	it("does not change multi-clip timelines or non-growing durations", () => {
+	it("does not change multi-clip timelines", () => {
 		expect(
 			extendAutoFullTrackClip(
 				[
@@ -37,6 +37,9 @@ describe("extendAutoFullTrackClip", () => {
 				10_000,
 			),
 		).toBeNull();
+	});
+
+	it("does not change clips when the duration does not grow", () => {
 		expect(
 			extendAutoFullTrackClip(
 				[{ id: "clip-1", startMs: 0, endMs: 8_000, speed: 1 }],
@@ -46,4 +49,59 @@ describe("extendAutoFullTrackClip", () => {
 			),
 		).toBeNull();
 	});
+
+	it("does not change clips when the auto-created clip id is missing", () => {
+		expect(
+			extendAutoFullTrackClip(
+				[{ id: "clip-1", startMs: 0, endMs: 5_000, speed: 1 }],
+				null,
+				5_000,
+				8_000,
+			),
+		).toBeNull();
+	});
+
+	it("does not change clips when the previous auto-created end time is missing", () => {
+		expect(
+			extendAutoFullTrackClip(
+				[{ id: "clip-1", startMs: 0, endMs: 5_000, speed: 1 }],
+				"clip-1",
+				null,
+				8_000,
+			),
+		).toBeNull();
+	});
+
+	it("does not change clips when the reported duration shrinks", () => {
+		expect(
+			extendAutoFullTrackClip(
+				[{ id: "clip-1", startMs: 0, endMs: 8_000, speed: 1 }],
+				"clip-1",
+				8_000,
+				7_000,
+			),
+		).toBeNull();
+	});
+
+	it("does not change clips when the tracked clip id no longer matches", () => {
+		expect(
+			extendAutoFullTrackClip(
+				[{ id: "clip-1", startMs: 0, endMs: 5_000, speed: 1 }],
+				"clip-2",
+				5_000,
+				8_000,
+			),
+		).toBeNull();
+	});
+
+	it("does not change clips when the clip no longer starts at zero", () => {
+		expect(
+			extendAutoFullTrackClip(
+				[{ id: "clip-1", startMs: 250, endMs: 5_000, speed: 1 }],
+				"clip-1",
+				5_000,
+				8_000,
+			),
+		).toBeNull();
+	});
 });