test all JSON, text import functions

src/core/tasksIO.test.js

@@ -0,0 +1,95 @@
+import { exportTasksToJSON, importTasksFromJSON, 
+    importTasksFromString } from './tasksIO';
+
+describe('tasksIO', () => {
+
+    // test importTasksFromString
+    describe('importTasksFromString function', () => {
+      test('should convert 2 text lines into list of 2 tasks', () => {
+        const tasks = importTasksFromString([], "task 1\ntask 2");
+        expect(tasks.length).toBe(2);
+      });
+
+      test('should correctly ignore empty lines', () => {
+        const tasks = importTasksFromString([], "task 1\n\ntask 2");
+        expect(tasks.length).toBe(2);
+      });
+
+      test('should take empty input and return empty list', () => {
+        const tasks = importTasksFromString([], "");
+        expect(tasks.length).toBe(0);
+      });
+    });
+
+    // test exportTasksToJSON
+    describe('exportTasksToJSON function', () => {
+      test('should convert 2 tasks into JSON string', () => {
+        const tasks = [
+            { id: 1, text: "task 1" },
+            { id: 2, text: "task 2" }
+        ];
+        const jsonString = exportTasksToJSON(tasks);
+        expect(jsonString).toBe('[{"id":1,"text":"task 1"},{"id":2,"text":"task 2"}]');
+      });
+
+      test('should take empty input and return empty list', () => {
+        const jsonString = exportTasksToJSON([]);
+        expect(jsonString).toBe('[]');
+      });
+    });
+
+    // test importTasksFromJSON
+    describe('importTasksFromJSON function', () => {
+      let error;
+
+      beforeEach(() => {
+        error = jest.spyOn(console, 'error').mockImplementation(() => {});
+      });
+
+      afterEach(() => {
+        error.mockRestore();
+      });
+
+      test('should convert JSON string into 2 tasks', () => {
+        const jsonString = '[{"id":1,"text":"task 1"},{"id":2,"text":"task 2"}]';
+        const tasks = importTasksFromJSON(jsonString);
+        expect(tasks.length).toBe(2);
+      });
+
+      test('should take empty input and return empty list', () => {
+        const tasks = importTasksFromJSON('[]');
+        expect(tasks.length).toBe(0);
+      });
+
+      test('should throw error if JSON is not an array', () => {
+        const jsonString = '{"id":1,"text":"task 1"}';
+        const result = importTasksFromJSON(jsonString);
+        expect(result).toBe(null);
+        expect(console.error).toHaveBeenCalled();
+      });
+
+      test('should throw error if JSON is not an array of objects', () => {
+        const jsonString = '[{"id":1,"text":"task 1"}, 2]';
+        // expect(() => importTasksFromJSON(jsonString)).toThrow();
+        const result = importTasksFromJSON(jsonString);
+        expect(result).toBe(null);
+        expect(console.error).toHaveBeenCalled();
+      });
+
+      test('should throw error if JSON is not an array of objects with id and text properties', () => {
+        const jsonString = '[{"id":1,"text":"task 1"}, {"id":2}]';
+        // expect(() => importTasksFromJSON(jsonString)).toThrow();
+        const result = importTasksFromJSON(jsonString);
+        expect(result).toBe(null);
+        expect(console.error).toHaveBeenCalled();
+      });
+
+      test('should throw error if JSON is not an array of objects with id and text properties of correct types', () => {
+        const jsonString = '[{"id":1,"text":"task 1"}, {"id":"2","text":3}]';
+        // expect(() => importTasksFromJSON(jsonString)).toThrow();
+        const result = importTasksFromJSON(jsonString);
+        expect(result).toBe(null);
+        expect(console.error).toHaveBeenCalled();
+      });
+    });
+});