Add configurable skip delay (0-30s) for Skip Intro and Skip Credits

tests/utils.test.js

@@ -0,0 +1,30 @@
+const test = require("node:test");
+const assert = require("node:assert");
+const { loadUtils } = require("./helpers");
+
+test("clampDelaySeconds keeps in-range integer values as-is", () => {
+  const window = loadUtils();
+  assert.strictEqual(window.clampDelaySeconds(0), 0);
+  assert.strictEqual(window.clampDelaySeconds(5), 5);
+  assert.strictEqual(window.clampDelaySeconds(30), 30);
+});
+
+test("clampDelaySeconds clamps below 0 and above 30", () => {
+  const window = loadUtils();
+  assert.strictEqual(window.clampDelaySeconds(-5), 0);
+  assert.strictEqual(window.clampDelaySeconds(45), 30);
+});
+
+test("clampDelaySeconds rounds fractional values", () => {
+  const window = loadUtils();
+  assert.strictEqual(window.clampDelaySeconds(15.6), 16);
+  assert.strictEqual(window.clampDelaySeconds(15.4), 15);
+});
+
+test("clampDelaySeconds falls back to 0 for non-numeric input", () => {
+  const window = loadUtils();
+  assert.strictEqual(window.clampDelaySeconds("abc"), 0);
+  assert.strictEqual(window.clampDelaySeconds(undefined), 0);
+  assert.strictEqual(window.clampDelaySeconds(null), 0);
+  assert.strictEqual(window.clampDelaySeconds(NaN), 0);
+});