Add a timeout for the emitter unit tests

This will help us to diagnose any deadlocks. The unit tests should
pass within the 2 second limit.

Resolves: #555 (comment)

common/event_emitter_test.go

@@ -24,6 +24,7 @@ import (
 	"context"
 	"sync"
 	"testing"
+	"time"
 
 	"github.com/chromedp/cdproto"
 	"github.com/stretchr/testify/assert"
@@ -145,7 +146,7 @@ func TestBaseEventEmitter(t *testing.T) {
 		eventName := "AtomicIntEvent"
 		maxInt := 100
 
-		ctx, cancel := context.WithCancel(context.Background())
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*2)
 		emitter := NewBaseEventEmitter(ctx)
 		ch := make(chan Event)
 		emitter.on(ctx, []string{eventName}, ch)
@@ -158,11 +159,16 @@ func TestBaseEventEmitter(t *testing.T) {
 			defer wg.Done()
 
 			for expectedI != maxInt {
-				e := <-ch
+				var e Event
+				select {
+				case e = <-ch:
+				case <-ctx.Done():
+					assert.FailNow(t, "context cancelled before test completed, deadlock?")
+				}
 
 				i, ok := e.data.(int)
 				if !ok {
-					assert.Fail(t, "unexpected type read from channel", e.data)
+					assert.FailNow(t, "unexpected type read from channel", e.data)
 				}
 
 				assert.Equal(t, eventName, e.typ)
@@ -181,6 +187,12 @@ func TestBaseEventEmitter(t *testing.T) {
 			defer wg.Done()
 
 			for i := 0; i < maxInt; i++ {
+				select {
+				case <-ctx.Done():
+					assert.FailNow(t, "context cancelled before test completed, deadlock?")
+				default:
+				}
+
 				i := i
 				emitter.emit(eventName, i)
 			}
@@ -207,7 +219,7 @@ func TestBaseEventEmitter(t *testing.T) {
 		eventName2 := "AtomicIntEvent2"
 		maxInt := 100
 
-		ctx, cancel := context.WithCancel(context.Background())
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*2)
 		emitter := NewBaseEventEmitter(ctx)
 		ch := make(chan Event)
 		emitter.on(ctx, []string{eventName1, eventName2}, ch)
@@ -224,19 +236,24 @@ func TestBaseEventEmitter(t *testing.T) {
 					break
 				}
 
-				e := <-ch
+				var e Event
+				select {
+				case e = <-ch:
+				case <-ctx.Done():
+					assert.FailNow(t, "context cancelled before test completed, deadlock?")
+				}
 
 				switch e.typ {
 				case eventName1:
 					i, ok := e.data.(int)
 					if !ok {
-						assert.Fail(t, "unexpected type read from channel", e.data)
+						assert.FailNow(t, "unexpected type read from channel", e.data)
 					}
 					emitter.emit(eventName2, i)
 				case eventName2:
 					expectedI2++
 				default:
-					assert.Fail(t, "unexpected event type received")
+					assert.FailNow(t, "unexpected event type received")
 				}
 			}
 
@@ -250,6 +267,12 @@ func TestBaseEventEmitter(t *testing.T) {
 			defer wg.Done()
 
 			for i := 0; i < maxInt; i++ {
+				select {
+				case <-ctx.Done():
+					assert.FailNow(t, "context cancelled before test completed, deadlock?")
+				default:
+				}
+
 				i := i
 				emitter.emit(eventName1, i)
 			}