Timer operator

observablecreate.go

@@ -233,3 +233,19 @@ func Never() Observable {
 	out := make(chan interface{})
 	return newObservableFromChannel(out)
 }
+
+// Timer returns an Observable that emits the zeroed value of a float64 after a
+// specified delay, and then completes.
+func Timer(d Duration) Observable {
+	out := make(chan interface{})
+	go func() {
+		if d == nil {
+			time.Sleep(0)
+		} else {
+			time.Sleep(d.duration())
+		}
+		out <- 0.
+		close(out)
+	}()
+	return newObservableFromChannel(out)
+}

observablecreate_test.go

@@ -347,3 +347,19 @@ func TestRangeWithMaximumExceeded(t *testing.T) {
 	assert.NotNil(t, err)
 	assert.Nil(t, r)
 }
+
+func TestTimer(t *testing.T) {
+	d := new(mockDuration)
+	d.On("duration").Return(1 * time.Millisecond)
+
+	obs := Timer(d)
+
+	AssertThatObservable(t, obs, HasItems(float64(0)))
+	d.AssertCalled(t, "duration")
+}
+
+func TestTimerWithNilDuration(t *testing.T) {
+	obs := Timer(nil)
+
+	AssertThatObservable(t, obs, HasItems(float64(0)))
+}