npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@bbc/nightwatch-vrt

v2.0.0

Published

Nightwatch Visual Regression Testing tools

Downloads

2,912

Readme

Nightwatch VRT

Nightwatch Visual Regression Testing tools for nightwatch.js

Description

Nightwatch VRT extends nightwatch.js with an assertion that captures a screenshot of a DOM element identified by a selector and compares the screenshot against a baseline screenshot. If the baseline screenshot does not exist, it will be created the first time you run the test and the assertion will pass.

Configuration

Include the following sections in the nightwatch configuration file

Custom commands and assertions

Register nightwatch-vrt's assertion and commands:

    custom_commands_path: [
        'node_modules/@bbc/nightwatch-vrt/commands'
    ],
    custom_assertions_path: [
        'node_modules/@bbc/nightwatch-vrt/assertions'
    ]

Nightwatch VRT custom settings

Then, for global settings, add the visual_regression_settings entry to nightwatch's globals globals section

default: {
    "globals": {
        "visual_regression_settings": {
            "generate_screenshot_path": defaultScreenshotPathGenerator,
            "latest_screenshots_path": "vrt/latest",
            "latest_suffix": "",
            "baseline_screenshots_path": "vrt/baseline",
            "baseline_suffix": "",
            "diff_screenshots_path": "vrt/diff",
            "diff_suffix": "",
            "threshold": 0,
            "prompt": false,
            "always_save_diff_screenshot": false
        }
    }
}

| Property | Description | Defaults | |-----------------------------|------------------------------------------------------------------------------------------------------------------| -------------- | | generate_screenshot_path | Passed function that will generate a screenshot path | none | | latest_screenshots_path | Path to the most recently captured screenshots | "vrt/latest" | | latest_suffix | A string appended to the end of the latest captured screenshot* | "" | | baseline_screenshots_path | Path to the baseline expected screenshots | "vrt/baseline" | | baseline_suffix | A string appended to the end of the baseline screenshot* | "" | | diff_screenshots_path | Path to the diff image of the two screenshots | "vrt/diff" | | diff_suffix | A string appended to the end of the diff image* | "" | | threshold | Matching threshold, ranges from 0 to 1. Smaller values make the comparison more sensitive. | 0.0 | | prompt | If true, the user will be prompted to override baseline screenshot when the recently captured screenshot differs | false | | always_save_diff_screenshot | If true, recently captured screenshots will always override the baseline | false | * Only necessary if screenshots are set to reside in the same directory

Nightwatch VRT screenshot path generator

The screenshot path generator option accepts a function that generates a dynamic path based on the test properties, and returns that string.

| Parameter | Description | |------------------|------------------------------------------------------------------------------------------------| | nightwatchClient | The nightwatch client test instance | | basePath | The base path for the screenshot set in visual_regression_settings (e.g. *_screenshots_path) | | fileName | The file name; either the selector used or the custom name given for the test | | returns | A string which contains the full path - minus the file extension |

For example:

function generateScreenshotFilePath(nightwatchClient, basePath, fileName) {
    const moduleName = nightwatchClient.currentTest.module,
        testName = nightwatchClient.currentTest.name

    return path.join(process.cwd(), basePath, moduleName, testName, fileName)
}

Usage

In order to use nightwatch-vrt, you only need to invoke the screenshotIdenticalToBaseline assertion and pass a css selector for the DOM element to compare. You may also pass a custom filename, visual_regression_settings overrides, and a custom log message.

| Parameter | Description | |------------------|------------------------------------------------------------------------------------------------| | selector | Identifies the element that will be captured in the screenshot. | | fileName | Optional file name for this screenshot; defaults to the selector | | settings | Optional settings to override the defaults and visual_regression_settings | | message | Optional message for nightwatch to log upon completion |

module.exports = {
    'Test Google UI loads correctly': (browser) => {
        browser
            .url('https://www.google.co.uk')
            .assert.screenshotIdenticalToBaseline('body',  /* Optional */ 'custom-name', {threshold: 0.5}, 'VRT custom-name complete.')
            .end()
    }
}

The first time a test is run, a baseline screenshot will be created and stored on disk. You should always register the baseline screenshot in the code repository. Further executions of this test will compare against this baseline.