feat(grading) - add prefill to 0 and adjust prefill policies for some question types

- refactor to differentiate question types that can be prefilled either to 0 or max, both or neither (for previous code, only boolean for if it can be prefilled)
- TextResponse and Comprehension question types adjusted to allow prefilling to full
- add tests for different policies

Author: LWS49

client/app/bundles/course/assessment/submission/reducers/grading/__test__/index.test.js

@@ -0,0 +1,229 @@
+import { dispatch, store } from 'store';
+
+import actions, { questionTypes } from '../../../constants';
+
+const answerId = 3;
+
+const buildPayload = ({ questionType, grade, correct, testCases } = {}) => ({
+  submission: {
+    pointsAwarded: null,
+    basePoints: 1000,
+    submittedAt: '2017-05-11T17:02:17.000+08:00',
+    bonusEndAt: '2017-05-11T17:02:17.000+08:00',
+    bonusPoints: 0,
+  },
+  assessment: {},
+  annotations: [],
+  posts: [],
+  topics: [],
+  questions: [{ id: 1, type: questionType, maximumGrade: 10 }],
+  answers: [
+    {
+      id: answerId,
+      fields: {
+        id: answerId,
+        questionId: 1,
+      },
+      questionId: 1,
+      grading: {
+        grade,
+        id: answerId,
+      },
+      explanation: correct !== undefined ? { correct } : undefined,
+      testCases,
+    },
+  ],
+});
+
+const dispatchFetchSuccess = (payload) =>
+  dispatch({ type: actions.FETCH_SUBMISSION_SUCCESS, payload });
+
+const getGrade = () =>
+  store.getState().assessments.submission.grading.questions[1].grade;
+
+describe('getPrefilledGrade via FETCH_SUBMISSION_SUCCESS', () => {
+  describe('general behavior', () => {
+    it('preserves existing grade even if answer is correct', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.MultipleChoice,
+          grade: 5,
+          correct: true,
+        }),
+      );
+
+      expect(getGrade()).toBe(5);
+    });
+
+    it('preserves existing grade even if answer is incorrect', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.MultipleChoice,
+          grade: 8,
+          correct: false,
+        }),
+      );
+
+      expect(getGrade()).toBe(8);
+    });
+
+    it('leaves grade as null when there is no explanation', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.MultipleChoice,
+          grade: null,
+          correct: undefined,
+        }),
+      );
+
+      expect(getGrade()).toBeNull();
+    });
+  });
+
+  describe('Question Types with ALWAYS_PREFILL_POLICY', () => {
+    it('prefills maximum grade for an ungraded correct answer', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.MultipleChoice,
+          grade: null,
+          correct: true,
+        }),
+      );
+
+      expect(getGrade()).toBe(10);
+    });
+
+    it('prefills 0 for an ungraded incorrect answer', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.MultipleChoice,
+          grade: null,
+          correct: false,
+        }),
+      );
+
+      expect(getGrade()).toBe(0);
+    });
+  });
+
+  describe('Question Types with NEVER_PREFILL_POLICY', () => {
+    it('does not prefill for an ungraded correct answer', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.VoiceResponse,
+          grade: null,
+          correct: true,
+        }),
+      );
+
+      expect(getGrade()).toBeNull();
+    });
+
+    it('does not prefill for an ungraded incorrect answer', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.VoiceResponse,
+          grade: null,
+          correct: false,
+        }),
+      );
+
+      expect(getGrade()).toBeNull();
+    });
+  });
+
+  describe('Question Types with ONLY_PREFILL_FULL_POLICY', () => {
+    it('prefills maximum grade for an ungraded correct answer', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.TextResponse,
+          grade: null,
+          correct: true,
+        }),
+      );
+
+      expect(getGrade()).toBe(10);
+    });
+
+    it('does not prefill 0 for an ungraded incorrect answer', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.TextResponse,
+          grade: null,
+          correct: false,
+        }),
+      );
+
+      expect(getGrade()).toBeNull();
+    });
+
+    it('prefills maximum grade for an ungraded fully correct MRQ answer', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.MultipleResponse,
+          grade: null,
+          correct: true,
+        }),
+      );
+
+      expect(getGrade()).toBe(10);
+    });
+
+    it('does not prefill 0 for an ungraded incorrect MRQ answer (partial credit possible)', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.MultipleResponse,
+          grade: null,
+          correct: false,
+        }),
+      );
+
+      expect(getGrade()).toBeNull();
+    });
+  });
+
+  describe('Programming', () => {
+    const withTestCases = {
+      public_test: [{ identifier: 'test1' }],
+    };
+
+    it('prefills maximum grade when test cases exist and answer is correct', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.Programming,
+          grade: null,
+          correct: true,
+          testCases: withTestCases,
+        }),
+      );
+
+      expect(getGrade()).toBe(10);
+    });
+
+    it('does not prefill 0 when test cases exist and answer is incorrect', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.Programming,
+          grade: null,
+          correct: false,
+          testCases: withTestCases,
+        }),
+      );
+
+      expect(getGrade()).toBeNull();
+    });
+
+    it('leaves grade as null when no test cases exist, even if answer is correct', () => {
+      dispatchFetchSuccess(
+        buildPayload({
+          questionType: questionTypes.Programming,
+          grade: null,
+          correct: true,
+          testCases: null,
+        }),
+      );
+
+      expect(getGrade()).toBeNull();
+    });
+  });
+});