[FAB-2901] Fixing election test

During latest changes leader election callback invocation
was changed from sync to async (go routine). It caused to tests
that check if callback was invoked run before it was actually
invoked. Test changed to handle this - if result is not as expected,
we wait for a while and check again.

Change-Id: Ib26dc5c7d48110c36d39a216e83bcc4a99981389
Signed-off-by: Gennady Laventman <[email protected]>

gossip/election/election_test.go

@@ -207,8 +207,8 @@ func TestInitPeersAtSameTime(t *testing.T) {
 	leaders := waitForLeaderElection(t, peers)
 	isP0leader := peers[len(peers)-1].IsLeader()
 	assert.True(t, isP0leader, "p0 isn't a leader. Leaders are: %v", leaders)
-	assert.True(t, peers[len(peers)-1].isLeaderFromCallback(), "p0 didn't got leaderhip change callback invoked")
 	assert.Len(t, leaders, 1, "More than 1 leader elected")
+	waitForBoolFunc(t, peers[len(peers)-1].isLeaderFromCallback, true, "Leadership callback result is wrong for ", peers[len(peers)-1].id)
 }
 
 func TestInitPeersStartAtIntervals(t *testing.T) {
@@ -289,12 +289,12 @@ func TestConvergence(t *testing.T) {
 
 	for _, p := range combinedPeers {
 		if p.id == finalLeaders[0] {
-			assert.True(t, p.isLeaderFromCallback(), "Leadership callback result is wrong for ", p.id)
-			assert.True(t, p.isCallbackInvoked(), "Leadership callback wasn't invoked for ", p.id)
+			waitForBoolFunc(t, p.isLeaderFromCallback, true, "Leadership callback result is wrong for ", p.id)
+			waitForBoolFunc(t, p.isCallbackInvoked, true, "Leadership callback wasn't invoked for ", p.id)
 		} else {
-			assert.False(t, p.isLeaderFromCallback(), "Leadership callback result is wrong for ", p.id)
+			waitForBoolFunc(t, p.isLeaderFromCallback, false, "Leadership callback result is wrong for ", p.id)
 			if p.id == leaders2[0] {
-				assert.True(t, p.isCallbackInvoked(), "Leadership callback wasn't invoked for ", p.id)
+				waitForBoolFunc(t, p.isCallbackInvoked, true, "Leadership callback wasn't invoked for ", p.id)
 			}
 		}
 	}
@@ -327,7 +327,7 @@ func TestPartition(t *testing.T) {
 	leaders := waitForLeaderElection(t, peers)
 	assert.Len(t, leaders, 1, "Only 1 leader should have been elected")
 	assert.Equal(t, "p0", leaders[0])
-	assert.True(t, peers[len(peers)-1].isLeaderFromCallback(), "Leadership callback result is wrong for %s", peers[len(peers)-1].id)
+	waitForBoolFunc(t, peers[len(peers)-1].isLeaderFromCallback, true, "Leadership callback result is wrong for %s", peers[len(peers)-1].id)
 
 	for _, p := range peers {
 		p.On("Peers").Return([]Peer{})
@@ -337,7 +337,7 @@ func TestPartition(t *testing.T) {
 	leaders = waitForMultipleLeadersElection(t, peers, 6)
 	assert.Len(t, leaders, 6)
 	for _, p := range peers {
-		assert.True(t, p.isLeaderFromCallback(), "Leadership callback result is wrong for %s", p.id)
+		waitForBoolFunc(t, p.isLeaderFromCallback, true, "Leadership callback result is wrong for %s", p.id)
 	}
 
 	for _, p := range peers {
@@ -352,10 +352,10 @@ func TestPartition(t *testing.T) {
 	assert.Equal(t, "p0", leaders[0])
 	for _, p := range peers {
 		if p.id == leaders[0] {
-			assert.True(t, p.isLeaderFromCallback(), "Leadership callback result is wrong for %s", p.id)
+			waitForBoolFunc(t, p.isLeaderFromCallback, true, "Leadership callback result is wrong for %s", p.id)
 		} else {
-			assert.False(t, p.isLeaderFromCallback(), "Leadership callback result is wrong for %s", p.id)
-			assert.True(t, p.isCallbackInvoked(), "Leadership callback wasn't invoked for %s", p.id)
+			waitForBoolFunc(t, p.isLeaderFromCallback, false, "Leadership callback result is wrong for %s", p.id)
+			waitForBoolFunc(t, p.isCallbackInvoked, true, "Leadership callback wasn't invoked for %s", p.id)
 		}
 	}
 
@@ -398,3 +398,14 @@ func TestConfigFromFile(t *testing.T) {
 	assert.Equal(t, time.Second*5, getLeaderElectionDuration())
 	assert.Equal(t, getLeaderAliveThreshold()/2, getLeadershipDeclarationInterval())
 }
+
+func waitForBoolFunc(t *testing.T, f func() bool, expectedValue bool, msgAndArgs ...interface{}) {
+	end := time.Now().Add(testTimeout)
+	for time.Now().Before(end) {
+		if f() == expectedValue {
+			return
+		}
+		time.Sleep(testPollInterval)
+	}
+	assert.Fail(t, fmt.Sprintf("Should be %t", expectedValue), msgAndArgs...)
+}