Reviewed tests for race conditions (#11)

Author: m-messer

internal/execution/worker/worker_test.go

@@ -24,7 +24,13 @@ func TestWorker_Start_IsAlive(t *testing.T) {
 
 	defer w.Kill()
 
-	assert.Equal(t, true, util.IsProcessAlive(w.Pid()))
+	pid := w.Pid()
+	require.NotZero(t, pid, "pid should be set after Start")
+
+	require.Eventually(t, func() bool {
+		return util.IsProcessAlive(pid)
+	}, 2*time.Second, 10*time.Millisecond, "process never reported alive")
+
 }
 
 func TestWorker_Start_FailsIfStarted(t *testing.T) {
@@ -35,8 +41,14 @@ func TestWorker_Start_FailsIfStarted(t *testing.T) {
 
 	defer w.Kill()
 
-	err = w.Start(context.Background())
-	assert.Error(t, err)
+	require.Eventually(t, func() bool {
+		pid := w.Pid()
+		return pid != 0 && util.IsProcessAlive(pid)
+	}, 2*time.Second, 10*time.Millisecond, "worker never became alive")
+
+	// Now a second Start should deterministically fail.
+	secondWorkerErr := w.Start(context.Background())
+	require.Error(t, secondWorkerErr)
 }
 
 func TestWorker_Start_ReturnsErrorIfInvalidCommand(t *testing.T) {
@@ -72,7 +84,7 @@ func TestWorker_TerminatesIfContextCancelled(t *testing.T) {
 	require.Eventually(t, func() bool {
 		evt, waitError = w.Wait(context.Background())
 		return waitError == nil && evt.Signal != nil
-	}, time.Second, 10*time.Millisecond)
+	}, 5*time.Second, 10*time.Millisecond)
 
 	require.NoError(t, waitError)
 	require.NotNil(t, evt)
@@ -125,6 +137,7 @@ func TestWorker_Wait_ReturnsErrorIfContextCancelled(t *testing.T) {
 	_, err = w.Wait(ctx)
 	assert.Error(t, err)
 }
+
 func TestWorker_Wait_ReturnsErrorIfCalledMultiple(t *testing.T) {
 	w := worker.NewProcessWorker(context.Background(), worker.StartConfig{Cmd: "cat"}, zap.NewNop())
 
@@ -184,6 +197,7 @@ func TestWorker_Kill_KillsProcess(t *testing.T) {
 		evt, waitError = w.Wait(context.Background())
 		return waitError == nil && evt.Signal != nil
 	}, time.Second, 10*time.Millisecond)
+	require.NoError(t, waitError)
 }
 
 func TestWorker_Terminate_TerminatesProcess(t *testing.T) {
@@ -274,5 +288,11 @@ func TestWorker_Read_ReadsFromStdout(t *testing.T) {
 	_, err = io.Copy(&outputBuf, readPipe)
 	assert.NoError(t, err)
 
-	assert.Equal(t, "foobar\n", outputBuf.String())
+	expected := "foobar\n"
+
+	require.Eventually(t, func() bool {
+		return outputBuf.String() == expected
+	}, 2*time.Second, 10*time.Millisecond)
+
+	require.Equal(t, expected, outputBuf.String())
 }