test: add StreamController unit test

src/controller/stream-controller.js

@@ -15,7 +15,7 @@ import {logger} from '../utils/logger';
 import { alignDiscontinuities } from '../utils/discontinuities';
 import TaskLoop from '../task-loop';
 
-const State = {
+export const State = {
   STOPPED : 'STOPPED',
   IDLE : 'IDLE',
   KEY_LOADING : 'KEY_LOADING',

tests/unit/controller/stream-controller.js

@@ -0,0 +1,32 @@
+import assert from "assert";
+import sinon from "sinon";
+import Hls from "../../../src/hls";
+import Event from "../../../src/events";
+import { FragmentTracker } from "../../../src/helper/fragment-tracker";
+import StreamController, { State } from "../../../src/controller/stream-controller";
+
+/**
+ * @returns {{hls: Hls, streamController: StreamController}}
+ */
+const createStreamController = () => {
+  const hls = new Hls({});
+  const fragmentTracker = new FragmentTracker(hls);
+  return {
+    hls,
+    streamController: new StreamController(hls, fragmentTracker)
+  };
+};
+
+describe("StreamController", function() {
+  it("initial state should be STOPPED", function() {
+    const { streamController } = createStreamController();
+    assert.equal(streamController.state, State.STOPPED);
+  });
+  it("should trigger STREAM_STATE_TRANSITION when state is updated", function() {
+    const { hls, streamController } = createStreamController();
+    const spy = sinon.spy();
+    hls.on(Event.STREAM_STATE_TRANSITION, spy);
+    streamController.state = State.ENDED;
+    assert.deepEqual(spy.args[0][1], { previousState: State.STOPPED, nextState: State.ENDED });
+  });
+});