Refactor more code to use testutils.WasCalled (#13054)

* Refactor more code to use testutils.WasCalled

* incorporate review comments

* Revert watcher_test.go changes

The file is in config package and the other tests use config_test.
So it is not visible.

config/file_test.go

@@ -477,11 +477,7 @@ func TestFileStoreSet(t *testing.T) {
 		require.NoError(t, err)
 		assert.Equal(t, oldCfg, retCfg)
 
-		select {
-		case <-called:
-		case <-time.After(5 * time.Second):
-			require.Fail(t, "callback should have been called when config written")
-		}
+		require.True(t, wasCalled(called, 5*time.Second), "callback should have been called when config written")
 	})
 
 	t.Run("watcher restarted", func(t *testing.T) {
@@ -513,11 +509,7 @@ func TestFileStoreSet(t *testing.T) {
 		require.NoError(t, err)
 
 		ioutil.WriteFile(path, cfgData, 0644)
-		select {
-		case <-called:
-		case <-time.After(5 * time.Second):
-			require.Fail(t, "callback should have been called when config written")
-		}
+		require.True(t, wasCalled(called, 5*time.Second), "callback should have been called when config written")
 	})
 }
 
@@ -749,11 +741,7 @@ func TestFileStoreLoad(t *testing.T) {
 		err = fs.Load()
 		require.NoError(t, err)
 
-		select {
-		case <-called:
-		case <-time.After(5 * time.Second):
-			require.Fail(t, "callback should have been called when config loaded")
-		}
+		require.True(t, wasCalled(called, 5*time.Second), "callback should have been called when config loaded")
 	})
 }
 
@@ -786,11 +774,7 @@ func TestFileStoreWatcherEmitter(t *testing.T) {
 		require.NoError(t, err)
 
 		ioutil.WriteFile(path, cfgData, 0644)
-		select {
-		case <-called:
-			require.Fail(t, "callback should not have been called since watching disabled")
-		case <-time.After(1 * time.Second):
-		}
+		require.False(t, wasCalled(called, 1*time.Second), "callback should not have been called since watching disabled")
 	})
 
 	t.Run("enabled", func(t *testing.T) {
@@ -809,11 +793,7 @@ func TestFileStoreWatcherEmitter(t *testing.T) {
 		require.NoError(t, err)
 
 		ioutil.WriteFile(path, cfgData, 0644)
-		select {
-		case <-called:
-		case <-time.After(5 * time.Second):
-			require.Fail(t, "callback should have been called when config written")
-		}
+		require.True(t, wasCalled(called, 5*time.Second), "callback should have been called when config written")
 	})
 }
 
@@ -1126,3 +1106,14 @@ func TestFileStoreString(t *testing.T) {
 
 	assert.Equal(t, "file://"+path, fs.String())
 }
+
+// wasCalled reports whether a given callback channel was called
+// within the specified time duration or not.
+func wasCalled(c chan bool, duration time.Duration) bool {
+	select {
+	case <-c:
+		return true
+	case <-time.After(duration):
+	}
+	return false
+}