chore: Implement submissions selector unit tests (#46)

* chore: Adapted the selector unit test to exercise the submissions selectors

* chore: updated linting for new submissions selector unit tests

src/data/redux/submissions/selectors.test.js

@@ -0,0 +1,84 @@
+import { lockStatuses } from 'data/services/lms/constants';
+
+// import * in order to mock in-file references
+import * as selectors from './selectors';
+
+jest.mock('reselect', () => ({
+  createSelector: jest.fn((preSelectors, cb) => ({ preSelectors, cb })),
+}));
+
+// Test state for submissions
+const testState = {
+  submissions: {
+    allSubmissions: {
+      some: 'Test data',
+    },
+  },
+};
+
+describe('submission selectors unit tests', () => {
+  const { simpleSelectors, listData } = selectors;
+  describe('allSubmissions', () => {
+    it('returns allSubmissions entry from submissions data', () => {
+      expect(simpleSelectors.allSubmissions(testState)).toEqual(
+        testState.submissions.allSubmissions,
+      );
+    });
+  });
+  describe('listData selector', () => {
+    let cb;
+    let preSelectors;
+    beforeAll(() => {
+      ({ cb, preSelectors } = listData);
+    });
+    it('is a emmoized selector based on submissions.allSubmissions', () => {
+      expect(preSelectors).toEqual([simpleSelectors.allSubmissions]);
+    });
+    describe('return data', () => {
+      const submissions = [
+        {
+          gradeStatus: 'gradeStatus1',
+          lockStatus: lockStatuses.locked,
+          otherValues: 'some stuff 1',
+          submissionDate: 3,
+        },
+        {
+          gradeStatus: 'gradeStatus2',
+          lockStatus: lockStatuses.unlocked,
+          otherValues: 'some stuff2',
+          submissionDate: 1,
+        },
+        {
+          gradeStatus: 'gradeStatus1',
+          lockStatus: lockStatuses.locked,
+          otherValues: 'some stuff 3',
+          submissionDate: 2,
+        },
+      ];
+      const allSubmissions = {
+        'test-submission-1': submissions[0],
+        'test-submission-2': submissions[1],
+        'test-submission-3': submissions[2],
+      };
+      let output;
+      beforeAll(() => {
+        output = cb(allSubmissions);
+      });
+      test('is ordered by submissionDate and includes only gradingStatus, submissionDate, and otherValues', () => {
+        expect(output[0].otherValues).toEqual(submissions[1].otherValues);
+        expect(output[1].otherValues).toEqual(submissions[2].otherValues);
+        expect(output[2].otherValues).toEqual(submissions[0].otherValues);
+        output.forEach(sub => {
+          expect(Object.keys(sub)).toEqual(
+            ['gradingStatus', 'otherValues', 'submissionDate'],
+          );
+        });
+      });
+      test('returns gradingStatus as GradeStatus iff lockstatus is lock, else lockStatus', () => {
+        expect(output[0].gradingStatus).toEqual(submissions[1].gradeStatus);
+        expect(output[1].gradingStatus).toEqual(submissions[2].lockStatus);
+        expect(output[2].gradingStatus).toEqual(submissions[0].lockStatus);
+      });
+    });
+  });
+});