[#46] Fixed issue with jest failure if error happens in steps (#47)

Author: NimaSoroush

CHANGELOG.md

@@ -1,5 +1,9 @@
+## [1.1.4] - 2017-11-03
+### Fixed
+- Fixed issue with jest failure if error happens in steps
+
 ## [1.1.3] - 2017-10-30
-### Changed
+### Fixed
 - Fixed issue with calling cleanup
 - Improved readme file
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "differencify",
-  "version": "1.1.3",
+  "version": "1.1.4",
   "description": "Perceptual diffing tool",
   "main": "dist/index.js",
   "scripts": {

src/helpers/proxyChain.js

@@ -75,7 +75,7 @@ const chainProxy = (target) => {
   const defaultParams = {
     resultFuncName: 'result',
     endFuncName: 'end',
-    updateFunctionName: '_compareImage',
+    updateFunctionName: '_evaluateResult',
   };
   const chainObject = new ChainObject(target, defaultParams);
   return new Proxy(

src/helpers/proxyChain.test.js

@@ -8,7 +8,7 @@ class ForTest {
     return this._value;
   }
 
-  _compareImage() { return this._value; }
+  _evaluateResult() { return this._value; }
   toMatchSnapshot() { this._value = 'Executed first'; }
 
   async echo(text) {

src/page.js

@@ -1,6 +1,6 @@
 import puppeteer from 'puppeteer';
 import logger from './utils/logger';
-import toMatchImageSnapshot from './utils/jestMatchImageSnapshot';
+import jestMatchers from './utils/jestMatchers';
 import compareImage from './compareImage';
 import functionToString from './helpers/functionToString';
 import freezeImage from './freezeImage';
@@ -12,12 +12,12 @@ export default class Page {
     this.browser = browser;
     this.tab = null;
     this.prefixedLogger = logger.prefix(this.testConfig.testName);
-    this.error = false;
+    this.error = null;
     this.image = null;
   }
 
   _logError(error) {
-    this.error = true;
+    this.error = error;
     this.prefixedLogger.error(error);
   }
 
@@ -123,22 +123,31 @@ export default class Page {
     }
   }
 
-  async _compareImage() {
+  async _evaluateResult() {
     if (!this.error) {
       let result;
       try {
         result = await compareImage(this.image, this.globalConfig, this.testConfig);
       } catch (error) {
         this._logError(error);
       }
+      if (this.error) {
+        return false;
+      }
       if (this.testConfig.isJest === true) {
+        const toMatchImageSnapshot = jestMatchers.toMatchImageSnapshot;
         expect.extend({ toMatchImageSnapshot });
         expect(result).toMatchImageSnapshot(this.testStats);
       }
       if (result.matched || result.updated || result.added) {
         return true;
       }
     }
+    if (this.testConfig.isJest && this.error) {
+      const toNotError = jestMatchers.toNotError;
+      expect.extend({ toNotError });
+      expect(this.error).toNotError(this.testStats);
+    }
     return false;
   }
 

src/page.test.js

@@ -4,6 +4,18 @@ import { globalConfig, testConfig } from './config/defaultConfigs';
 import functionToString from './helpers/functionToString';
 import freezeImage from './freezeImage';
 import { sanitiseGlobalConfiguration } from './sanitiser';
+import jestMatchers from './utils/jestMatchers';
+import compareImage from './compareImage';
+
+const mockMatcher = jest.fn(() => ({
+  message: 'message',
+  pass: true,
+}));
+
+jestMatchers.toNotError = mockMatcher;
+jestMatchers.toMatchImageSnapshot = mockMatcher;
+
+jest.mock('./compareImage');
 
 const tabMocks = {
   goto: jest.fn(),
@@ -53,7 +65,10 @@ describe('Page', () => {
   afterEach(() => {
     puppeteer.launch.mockClear();
     mockLog.mockClear();
+    mockErr.mockClear();
     functionToString.mockClear();
+    mockMatcher.mockClear();
+    compareImage.mockClear();
     page.error = false;
   });
   beforeEach(() => {
@@ -159,6 +174,27 @@ describe('Page', () => {
       expect(mockErr).toHaveBeenCalledTimes(0);
     });
   });
+  describe('_evaluateResult', () => {
+    it('it calls toNotError if error happens in any steps when in jest mode', async () => {
+      page.error = new Error('Error happened');
+      const result = await page._evaluateResult();
+      expect(jestMatchers.toNotError).toHaveBeenCalled();
+      expect(result).toEqual(false);
+    });
+    it('it wont calls toMatchImageSnapshot when in jest mode and compareImage throws', async () => {
+      const result = await page._evaluateResult();
+      expect(compareImage).toHaveBeenCalled();
+      expect(jestMatchers.toMatchImageSnapshot).not.toHaveBeenCalled();
+      expect(result).toEqual(false);
+    });
+    it('it calls toMatchImageSnapshot when in jest mode', async () => {
+      compareImage.mockReturnValueOnce({ matched: true });
+      const result = await page._evaluateResult();
+      expect(compareImage).toHaveBeenCalled();
+      expect(jestMatchers.toMatchImageSnapshot).toHaveBeenCalled();
+      expect(result).toEqual(true);
+    });
+  });
   describe('FreezeImage', () => {
     beforeEach(() => {
       tabMocks.evaluate.mockClear();

src/utils/jestMatchImageSnapshot.js renamed to src/utils/jestMatchers.js

@@ -28,4 +28,21 @@ const toMatchImageSnapshot = (result, testState) => {
   };
 };
 
-export default toMatchImageSnapshot;
+const toNotError = (error, testState) => {
+  const snapshotState = testState;
+  expect.setState(snapshotState, {
+    _counters: snapshotState.snapshotState._counters.set(
+      snapshotState.currentTestName,
+      (snapshotState.snapshotState._counters.get(snapshotState.currentTestName) || 0) + 1,
+    ),
+  });
+
+  const message = () => 'Failed to run your test.\n'
+                  + `${chalk.bold.red('Cause:')} ${chalk.red(error)}`;
+  return {
+    message,
+    pass: false,
+  };
+};
+
+export default { toMatchImageSnapshot, toNotError };