test: add unit tests for base algorithm

src/spaced-repetition/index.test.ts

@@ -0,0 +1,108 @@
+import { vi, describe, expect, it, beforeEach } from 'vitest';
+import {
+  CardState,
+  CardType,
+  SpacedRepetitionAlgorithm,
+  SpacedRepetitionItem,
+} from '.';
+
+class TestAlgorithm extends SpacedRepetitionAlgorithm<{}> {
+  getDefaultValues() {
+    return {};
+  }
+  scheduleReview() {}
+  getNextReviewItem() {
+    return null;
+  }
+  updateItemAfterReview() {}
+}
+
+let algorithm: TestAlgorithm;
+let mockItem: SpacedRepetitionItem;
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  algorithm = new TestAlgorithm();
+  mockItem = {
+    id: '1',
+    type: CardType.BASIC,
+    easeFactor: 2.5,
+    interval: 1,
+    iteration: 0,
+    state: CardState.NEW,
+    stepIndex: 0,
+    content: { front: 'Front', back: 'Back' },
+  };
+});
+
+describe('addItem', () => {
+  it('should add an item to the items array', () => {
+    algorithm.addItem(mockItem);
+    expect(algorithm['items']).toContain(mockItem);
+  });
+
+  it('should call `scheduleReview` for the added item', () => {
+    const spy = vi.spyOn(algorithm, 'scheduleReview');
+    algorithm.addItem(mockItem);
+    expect(spy).toHaveBeenCalledWith(mockItem);
+  });
+});
+
+describe('removeItem', () => {
+  it('should remove an item from the items array', () => {
+    algorithm.addItem(mockItem);
+    algorithm.removeItem(mockItem);
+    expect(algorithm['items']).not.toContain(mockItem);
+  });
+
+  it('should not modify the array if the item is not found', () => {
+    algorithm.addItem(mockItem);
+    const nonExistentItem = { ...mockItem, id: '2' };
+    algorithm.removeItem(nonExistentItem);
+    expect(algorithm['items'].length).toBe(1);
+  });
+});
+
+describe('startNewSession', () => {
+  it('should reset session end time and clear queued items', () => {
+    const now = new Date();
+    algorithm['queuedItems'] = [mockItem];
+    algorithm.startNewSession();
+    expect(algorithm['sessionEndTime'].toDateString()).toBe(
+      algorithm['getEndOfDay'](now).toDateString(),
+    );
+    expect(algorithm['queuedItems']).toEqual([]);
+  });
+
+  it('should call `refreshQueue`', () => {
+    const spy = vi.spyOn(algorithm, 'refreshQueue' as keyof TestAlgorithm);
+    algorithm.startNewSession();
+    expect(spy).toHaveBeenCalled();
+  });
+});
+
+describe('isDueToday', () => {
+  it('should return true for new items', () => {
+    expect(algorithm.isDueToday(mockItem)).toBe(true);
+  });
+
+  it('should return true for items due today', () => {
+    const dueItem = {
+      ...mockItem,
+      state: CardState.REVIEW,
+      nextReviewDate: new Date(),
+    };
+    expect(algorithm.isDueToday(dueItem)).toBe(true);
+  });
+
+  it('should return false for items due in the future', () => {
+    const futureDate = new Date();
+    futureDate.setDate(futureDate.getDate() + 1);
+    const notDueItem = {
+      ...mockItem,
+      state: CardState.REVIEW,
+      nextReviewDate: futureDate,
+    };
+    expect(algorithm.isDueToday(notDueItem)).toBe(false);
+  });
+});