making tests a little better

client_test.go

@@ -5,43 +5,75 @@ import (
 	"time"
 )
 
+func makeClient(doc *Document) (*Client, chan []Delta) {
+	ch := make(chan []Delta, 5)
+	client := doc.Client(DeltaHandlerFunc(func(ds []Delta) error {
+		ch <- ds
+		return nil
+	}))
+	return client, ch
+}
+
+func receiveMessages(ch chan []Delta, expected ...Delta) error {
+	select {
+	case got := <-ch:
+		if len(got) != len(expected) {
+			return fmt.Errorf("got %d deltas, expected %d", len(got), len(expected))
+		}
+		for i, gotD := range got {
+			if !gotD.Equal(expected[i]) {
+				return fmt.Errorf("didn't get the correct delta, saw: %v, expected: %v", gotD, expected[i])
+			}
+		}
+	case <-time.After(10 * time.Millisecond):
+		return fmt.Errorf("didn't get any delta")
+	}
+
+	return nil
+}
+
 func TestClient(t *testing.T) {
 	doc := NewString("")
 
-	aliceCh := make(chan []Delta, 5)
-	alice := doc.Client(DeltaHandlerFunc(func(ds []Delta) error {
-		aliceCh <- ds
-		return nil
-	}))
+	alice, aliceCh := makeClient(doc)
 	defer alice.Close()
 
-	bobCh := make(chan []Delta, 5)
-	bob := doc.Client(DeltaHandlerFunc(func(ds []Delta) error {
-		bobCh <- ds
-		return nil
-	}))
+	bob, bobCh := makeClient(doc)
 	defer bob.Close()
 
-	delta := Insert(0, 0, "alphabet")
+	charles, charlesCh := makeClient(doc)
+	defer charles.Close()
 
-	err := alice.PushDeltas(delta)
+	deltaA := Insert(0, 0, "alphabet")
+	deltaB := Insert(0, 8, "\nbatman")
+
+	err := alice.PushDeltas(deltaA)
 	if err != nil {
 		t.Error("got error pushing delta:", err)
 	}
 
-	select {
-	case got := <-bobCh:
-		if len(got) != 1 {
-			t.Errorf("got %d deltas, expected %d", len(got), 1)
-		} else if !got[0].Equal(delta) {
-			t.Error("didn't get the correct delta, saw:", got[0], "expected:", delta)
-		}
-	case <-time.After(10 * time.Millisecond):
-		t.Error("didn't get any delta")
+	err = bob.PushDeltas(deltaB)
+	if err != nil {
+		t.Error("got error pushing delta:", err)
 	}
 
-	if got := doc.Contents(); got != "alphabet" {
-		t.Errorf("saw doc %q, expected %q", got, "alphabet")
+	err = receiveMessages(aliceCh, deltaB)
+	if err != nil {
+		t.Error("alice didn't receive the correct messages:", err)
+	}
+
+	err = receiveMessages(bobCh, deltaA)
+	if err != nil {
+		t.Error("bob didn't receive the correct messages:", err)
+	}
+
+	err = receiveMessages(charlesCh, deltaA, deltaB)
+	if err != nil {
+		t.Error("charles didn't receive the correct messages:", err)
+	}
+
+	if got := doc.Contents(); got != "alphabet\nbatman" {
+		t.Errorf("saw doc %q, expected %q", got, "alphabet\nbatman")
 	}
 
 	select {
@@ -49,6 +81,8 @@ func TestClient(t *testing.T) {
 		t.Error("got an unexpected message via Bob")
 	case <-aliceCh:
 		t.Error("got an unexpected message via Alice")
+	case <-charlesCh:
+		t.Error("got an unexpected message via Charles")
 	case <-time.After(100 * time.Millisecond):
 		// expected
 	}