test: - Add more tests for RandomField

tests/Query/Filter/RandomField.test.ts

@@ -6,11 +6,21 @@ import moment from 'moment';
 import { RandomField } from '../../../src/Query/Filter/RandomField';
 import { fromLine } from '../../TestingTools/TestHelpers';
 import { expectTaskComparesEqual } from '../../CustomMatchers/CustomMatchersForSorting';
+import { TaskBuilder } from '../../TestingTools/TaskBuilder';
 
 window.moment = moment;
 
 const field = new RandomField();
 
+beforeAll(() => {
+    jest.useFakeTimers();
+    jest.setSystemTime(new Date('2024-01-23'));
+});
+
+afterAll(() => {
+    jest.useRealTimers();
+});
+
 describe('filtering by random', () => {
     it('should be named random', () => {
         expect(field.fieldName()).toEqual('random');
@@ -30,6 +40,36 @@ describe('sorting by random', () => {
         // Assert
         expectTaskComparesEqual(sorter, task1, task1);
     });
+
+    it('sort key should ignore task properties except description', () => {
+        const fullyPopulatedTask = TaskBuilder.createFullyPopulatedTask();
+        const taskWithSameDescription = new TaskBuilder().description(fullyPopulatedTask.description).build();
+        expect(field.sortKey(fullyPopulatedTask)).toEqual(field.sortKey(taskWithSameDescription));
+    });
+
+    it('sort key should not change, at different times', () => {
+        const task1 = fromLine({ line: '- [ ] My sort key should be same, regardless of time' });
+
+        jest.setSystemTime(new Date('2024-10-19 10:42'));
+        const sortKeyAtTime1 = field.sortKey(task1);
+
+        jest.setSystemTime(new Date('2024-10-19 21:05'));
+        const sortKeyAtTime2 = field.sortKey(task1);
+
+        expect(sortKeyAtTime1).toEqual(sortKeyAtTime2);
+    });
+
+    it('sort key should change on different dates', () => {
+        const task1 = fromLine({ line: '- [ ] My sort key should differ on different dates' });
+
+        jest.setSystemTime(new Date('2024-01-23'));
+        const sortKeyOnDay1 = field.sortKey(task1);
+
+        jest.setSystemTime(new Date('2024-01-24'));
+        const sortKeyOnDay2 = field.sortKey(task1);
+
+        expect(sortKeyOnDay1).not.toEqual(sortKeyOnDay2);
+    });
 });
 
 describe('grouping by random', () => {