Merge branch 'master' into fixHooksNamesBug

Author: haejinjo

src/backend/__tests__/astParser.test.js

@@ -0,0 +1,139 @@
+/* eslint-disable max-len */
+/* eslint-disable jest/no-disabled-tests */
+/* eslint-disable import/no-extraneous-dependencies */
+/* eslint-disable react/button-has-type */
+/* eslint-disable react/jsx-filename-extension */
+/* eslint-disable jest/valid-describe */
+/* eslint-disable react/react-in-jsx-scope */
+import { configure } from 'enzyme';
+import Adapter from 'enzyme-adapter-react-16';
+// import toJson from 'enzyme-to-json';
+import { throttle, getHooksNames } from '../helpers';
+
+// Newer Enzyme versions require an adapter to a particular version of React
+configure({ adapter: new Adapter() });
+
+// Replace any setTimeout functions with jest timer
+jest.useFakeTimers();
+
+describe('AST Unit Tests', () => {
+
+  describe('throttle', () => {
+    let mockFunc;
+    let throttledMockFunc;
+
+    beforeEach(() => {
+      mockFunc = jest.fn();
+      throttledMockFunc = throttle(mockFunc, 1000);
+    });
+
+    it('Should return a function', () => {
+      expect(typeof throttledMockFunc).toBe('function');
+    });
+
+    it('throttles subsequent fire attempts into one shot after cooldown', () => {
+      throttledMockFunc();
+      expect(mockFunc).toHaveBeenCalledTimes(1);
+      jest.advanceTimersByTime(20);
+      throttledMockFunc();
+      jest.advanceTimersByTime(20);
+      throttledMockFunc();
+      jest.advanceTimersByTime(20);
+      throttledMockFunc();
+      expect(mockFunc).toHaveBeenCalledTimes(1);
+
+      jest.advanceTimersByTime(941);
+
+      expect(mockFunc).toHaveBeenCalledTimes(2);
+    });
+
+    it('Should only invoke function', () => {
+      // Because we haven't invoked returned function from throttle
+      // mock func should not have been called yet
+      expect(mockFunc).not.toHaveBeenCalled();
+
+      throttledMockFunc();
+
+      expect(mockFunc).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  describe('getHooksNames', () => {
+    it('Should return object with one getter/setter for a single useState instance', () => {
+      const elementType = `function SingleUseFakeComponent() { 
+                            const [testCount, setTestCount] = useState(0);
+                            const age = 20; 
+                            return (<div> <p> You clicked this {testCount} times </p>
+                                    <button onClick={() => setTestCount(testCount + 1)}>+1</button>
+                                    <button onClick={() => setTestCount(testCount - 1)}>-1</button> <p>
+                                    You are {age} years old! </p>
+                                    <button onClick={age => age + 1}>Get Older</button>
+                                    <hr /> 
+                                    </div>);
+                           }`;
+
+      expect(getHooksNames(elementType)).toEqual(['testCount', 'setTestCount']);
+    });
+
+    it('Should output the right number of properties when taking in multiple function definitions', () => {
+      const elementType = `function SingleUseFakeComponent() { 
+                            const [testCount, setTestCount] = useState(0);
+                            const [biscuitCount, setBiscuitCount] = useState(0);
+                            const age = 20; 
+                            return (<div> <p> You clicked this {testCount} times </p>
+                                    <button onClick={() => setTestCount(testCount + 1)}>+1</button>
+                                    <button onClick={() => setTestCount(testCount - 1)}>-1</button> <p>
+                                    You are {age} years old! </p>
+                                    <button onClick={age => age + 1}>Get Older</button>
+                                    <hr /> 
+                                    </div>);
+                          }`;
+
+      expect(getHooksNames(elementType)).toEqual(['testCount', 'setTestCount', 'biscuitCount', 'setBiscuitCount']);
+      expect(Object.keys(getHooksNames(elementType))).toHaveLength(4);
+    });
+
+    it('Should ignore any non-hook definitions', () => {
+      const elementType = `function SingleUseFakeComponent() { 
+                            const [testCount, setTestCount] = useState(0);
+                            const age = 20; 
+                            return (<div> <p> You clicked this {testCount} times </p>
+                                    <button onClick={() => setTestCount(testCount + 1)}>+1</button>
+                                    <button onClick={() => setTestCount(testCount - 1)}>-1</button> <p>
+                                    You are {age} years old! </p>
+                                    <button onClick={age => age + 1}>Get Older</button>
+                                    <hr /> 
+                                    </div>);
+                          }`;
+
+      const expectedNumHookVariables = 2;
+      expect(Object.keys(getHooksNames(elementType))).toHaveLength(expectedNumHookVariables);
+    });
+
+    it('Should return an empty object if no hooks found', () => {
+      const elementType = `function SingleUseFakeComponent() { 
+                            const age = 20; 
+                            return (<div> <p> You clicked this {testCount} times </p>
+                                    <button onClick={() => setTestCount(testCount + 1)}>+1</button>
+                                    <button onClick={() => setTestCount(testCount - 1)}>-1</button> <p>
+                                    You are {age} years old! </p>
+                                    <button onClick={age => age + 1}>Get Older</button>
+                                    <hr /> 
+                                    </div>);
+                          }`;
+
+      expect(getHooksNames(elementType)).toEqual([]);
+    });
+
+    it('Should throw an error if input returns invalid JSX', () => {
+      const useState = `const singleUseStateTest = () => { 
+                        age: 20; 
+                        return (<p> You are {age} years old! </p> 
+                                  <button onClick={age + 1}>Get Older</button>
+                                 </div>)
+                        }`;
+
+      expect(getHooksNames(useState)).toEqual(['unknown']);
+    });
+  });
+});