fix: check for if an answer changes to false (#250)

src/editors/containers/ProblemEditor/components/EditProblemView/SettingsWidget/hooks.js

@@ -206,12 +206,19 @@ export const typeRowHooks = ({
   updateField,
   updateAnswer,
 }) => {
+  const clearPreviouslySelectedAnswers = () => {
+    answers.forEach(answer => {
+      if (answer.correct) {
+        updateAnswer({ ...answer, correct: false });
+      }
+    });
+  };
   const onClick = () => {
+    // Dropdown problems can only have one correct answer. When there is more than one correct answer
+    // from a previous problem type, the correct attribute for selected answers need to be set to false.
     if (typeKey === ProblemTypeKeys.DROPDOWN) {
       if (correctAnswerCount > 1) {
-        answers.forEach(answer => {
-          updateAnswer({ ...answer, correct: false });
-        });
+        clearPreviouslySelectedAnswers();
       }
     }
     if (blockTitle === ProblemTypes[problemType].title) {

src/editors/containers/ProblemEditor/components/EditProblemView/SettingsWidget/hooks.test.js

@@ -263,6 +263,10 @@ describe('Problem settings hooks', () => {
       {
         correct: true,
         id: 'b',
+      },
+      {
+        correct: false,
+        id: 'c',
       }];
       output = hooks.typeRowHooks({
         answers,
@@ -278,6 +282,7 @@ describe('Problem settings hooks', () => {
       expect(setBlockTitle).toHaveBeenCalledWith('Dropdown');
       expect(updateAnswer).toHaveBeenNthCalledWith(1, { ...answers[0], correct: false });
       expect(updateAnswer).toHaveBeenNthCalledWith(2, { ...answers[1], correct: false });
+      expect(updateAnswer).not.toHaveBeenNthCalledWith(3, { ...answers[2], correct: false });
       expect(updateField).toHaveBeenCalledWith({ problemType: typekey });
     });
   });