refactor: append test flag to shared test description

- so that the failed test is easy to identify
- shallow copy tests and add comments so that others do the same
Signed-off-by: vadasambar <[email protected]>

cluster-autoscaler/utils/drain/drain_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package drain
 
 import (
+	"fmt"
 	"testing"
 	"time"
 
@@ -645,13 +646,26 @@ func TestDrain(t *testing.T) {
 	}
 
 	allTests := []testOpts{}
+	// Note: be careful about modifying the underlying reference values for sharedTest
+	// since they are shared (changing it once will change it for all shallow copies of sharedTest)
 	for _, sharedTest := range sharedTests {
+		// make sure you shallow copy the test like this
+		// before you modify it
+		// (so that modifying one test doesn't affect another)
+		enabledTest := sharedTest
+		disabledTest := sharedTest
+
 		// to execute the same shared tests for when the skipNodesWithCustomControllerPods flag is true
 		// and when the flag is false
-		sharedTest.skipNodesWithCustomControllerPods = true
-		allTests = append(allTests, sharedTest)
-		sharedTest.skipNodesWithCustomControllerPods = false
-		allTests = append(allTests, sharedTest)
+		enabledTest.skipNodesWithCustomControllerPods = true
+		enabledTest.description = fmt.Sprintf("%s with skipNodesWithCustomControllerPods:%v",
+			enabledTest.description, enabledTest.skipNodesWithCustomControllerPods)
+		allTests = append(allTests, enabledTest)
+
+		disabledTest.skipNodesWithCustomControllerPods = false
+		disabledTest.description = fmt.Sprintf("%s with skipNodesWithCustomControllerPods:%v",
+			disabledTest.description, disabledTest.skipNodesWithCustomControllerPods)
+		allTests = append(allTests, disabledTest)
 	}
 
 	allTests = append(allTests, testOpts{
@@ -703,19 +717,19 @@ func TestDrain(t *testing.T) {
 		if test.expectFatal {
 			assert.Equal(t, test.expectBlockingPod, blockingPod)
 			if err == nil {
-				t.Fatalf("%s: unexpected non-error, skipNodesWithCustomControllerPods: %v", test.description, test.skipNodesWithCustomControllerPods)
+				t.Fatalf("%s: unexpected non-error", test.description)
 			}
 		}
 
 		if !test.expectFatal {
 			assert.Nil(t, blockingPod)
 			if err != nil {
-				t.Fatalf("%s: error occurred: %v, skipNodesWithCustomControllerPods: %v", test.description, err, test.skipNodesWithCustomControllerPods)
+				t.Fatalf("%s: error occurred: %v", test.description, err)
 			}
 		}
 
 		if len(pods) != len(test.expectPods) {
-			t.Fatalf("Wrong pod list content: %v, skipNodesWithCustomControllerPods: %v", test.description, test.skipNodesWithCustomControllerPods)
+			t.Fatalf("Wrong pod list content: %v", test.description)
 		}
 
 		assert.ElementsMatch(t, test.expectDaemonSetPods, daemonSetPods)