You can npm to install the package: npm install blue-harvest --save-dev, or if you are using Yarn, yarn add blue-harvest -D

In order for you to use async await in the tests, the following line

SELENIUM_PROMISE_MANAGER: false;

should be added to the protractor.conf.js file.

To regulate the resolution of the screenshots, add

onPrepare() {
    browser.driver.manage().window().setSize(1366, 1024);
    jasmine.getEnv().addReporter(new SpecReporter({ spec: { displayStacktrace: true } }));
  }

in protractor.conf.js, inside the config block.

To test if a page has changed from a previous screenshot:

let result =  await blueharvest.compareScreenshot(
                   await browser.takeScreenShot(), pathToGolden);

The difference between the two screenshots will be highlighted in pink.

When a change in a page is expected and not a regression, you can update the reference screenshots by setting UPDATE_GOLDENS=1 when you run the tests. In this case, if any test fails, blue-harvest will update the reference image with the new one. Only tests involving the reference screenshots (goldens) are required. You can edit the specs in protractor.conf.js so only necessary tests are run in an update.

In a Linux system, you can simply run UPDATE_GOLDENS=1 npm run e2e to update the reference screenshots. In a windows environment where the command cannot be directly run, you can put it in a shell file and add a npm script that runs bash ./filename.sh to update the reference screenshots.

If there is a part on a page that should be ignored in the screenshot tests, you can add a coloured mask to a certain element before you take the screenshot so it will not be compared each time the tests run. addMask() returns the mask element, which can be passed to removeMask() to be removed.

const e = element(by.css('element_to_ignore'));
const mask = await blueharvest.addMask(e, 'gray', 99999, 10, 20, 1.1);
const screenshot = await browser.takeScreenShot();
blueharvest.removeMask(mask);

The default z-index for the mask element is 10000. An optional zIndex argument can be passed to addMask() if you would like to increase the value of a mask's z-index. If the mask appears to be off the desired place, you can pass optional xOffset, yOffset and sizeMultiplier arguments to addMask() to move/shape the mask manually.