[#1501] Add tests cases to FeedbackRankOptionsQuestionDetails (#12475)

* Update FeedbackRankOptionsQuestionDetailsTest.java

Adding test case to
testValidateQuestionDetails_invalidMaxMinOptions_errorReturned()

* Update FeedbackRankOptionsQuestionDetailsTest.java

Adding new test case to FeedbackRankOptionsQuestionDetailsTest

---------

Co-authored-by: Dominic Lim <46486515+domlimm@users.noreply.github.com>
Co-authored-by: Wei Qing <48304907+weiquu@users.noreply.github.com>

src/test/java/teammates/common/datatransfer/questions/FeedbackRankOptionsQuestionDetailsTest.java

@@ -78,6 +78,24 @@ public void testValidateQuestionDetails_invalidMaxMinOptions_errorReturned() {
         errorResponse.add(FeedbackRankOptionsQuestionDetails.ERROR_MAX_OPTIONS_ENABLED_MORE_THAN_CHOICES);
         feedbackQuestionDetails.setOptions(Arrays.asList("1", "2", "3"));
         assertEquals(errorResponse, feedbackQuestionDetails.validateQuestionDetails());
+        errorResponse.clear();
+
+        feedbackQuestionDetails = new FeedbackRankOptionsQuestionDetails();
+        feedbackQuestionDetails.setMinOptionsToBeRanked(5);
+        feedbackQuestionDetails.setMaxOptionsToBeRanked(3);
+        feedbackQuestionDetails.setOptions(Arrays.asList("1", "2", "3", "4", "5"));
+        errorResponse.add(FeedbackRankOptionsQuestionDetails.ERROR_INVALID_MIN_OPTIONS_ENABLED);
+        assertEquals(errorResponse, feedbackQuestionDetails.validateQuestionDetails());
+        errorResponse.clear();
+
+        feedbackQuestionDetails = new FeedbackRankOptionsQuestionDetails();
+        feedbackQuestionDetails.setMaxOptionsToBeRanked(0);
+        feedbackQuestionDetails.setMinOptionsToBeRanked(0);
+        errorResponse.add(FeedbackRankOptionsQuestionDetails.ERROR_INVALID_MAX_OPTIONS_ENABLED);
+        errorResponse.add(FeedbackRankOptionsQuestionDetails.ERROR_INVALID_MIN_OPTIONS_ENABLED);
+        errorResponse.add(FeedbackRankOptionsQuestionDetails.ERROR_NOT_ENOUGH_OPTIONS
+                + FeedbackRankOptionsQuestionDetails.MIN_NUM_OF_OPTIONS + ".");
+        assertEquals(errorResponse, feedbackQuestionDetails.validateQuestionDetails());
     }
 
     @Test