fix(fromEvent): Throw if event target is invalid (#2107)

ReactiveX · Nov 5, 2016 · 147ce3e · 147ce3e
1 parent 39214f2
commit 147ce3e
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Showing 3 changed files with 17 additions and 1 deletion.
diff --git a/.markdown-doctest-setup.js b/.markdown-doctest-setup.js
@@ -23,7 +23,10 @@ module.exports = {
   globals: {
     document: {
       querySelector: function () {
-        return {addEventListener: function () {}}
+        return {
+          addEventListener: function () {},
+          removeEventListener: function () {}
+        }
       }
     },
     hot: marbleTesting.hot,

diff --git a/spec/observables/fromEvent-spec.ts b/spec/observables/fromEvent-spec.ts
@@ -115,6 +115,17 @@ describe('Observable.fromEvent', () => {
     expect(offHandler).to.equal(onHandler);
   });
 
+  it('should error on invalid event targets', () => {
+    const obj = {
+      addListener: () => {
+        //noop
+      }
+    };
+
+    const subscribe = () => Observable.fromEvent(<any>obj, 'click').subscribe();
+    expect(subscribe).to.throw(TypeError, 'Invalid event target');
+  });
+
   it('should pass through options to addEventListener', () => {
     let actualOptions;
     const expectedOptions = { capture: true, passive: true };

diff --git a/src/observable/FromEventObservable.ts b/src/observable/FromEventObservable.ts
@@ -133,6 +133,8 @@ export class FromEventObservable<T> extends Observable<T> {
       const source = sourceObj;
       sourceObj.addListener(eventName, handler);
       unsubscribe = () => source.removeListener(eventName, handler);
+    } else {
+      throw new TypeError('Invalid event target');
     }
 
     subscriber.add(new Subscription(unsubscribe));