Lighthouse for Azure Pipelines
This is an Azure DevOps extension that allows you to enhance your Azure Pipelines with a Lighthouse tab. The Lighthouse tab embed one or many HTML reports generated by Google Lighthouse.
The task only requires a target URL to execute Lighthouse against.
If the Lighthouse NPM package is already installed locally or globally on the agent, then the task will use it. Otherwise, it will install the latest version in a temporary folder.
You can also specify audit score assertions that can make the pipeline fail based on the audit scores.
For example, the Google Lighthouse audit no-vulnerable-libraries produces a boolean score that will be equal to 1 if there are no known vulnerabilities within client-side JavaScript libraries and frameworks detected on a web site.
This is an example of a score assertion for this audit:
no-vulnerable-libraries = 1
Which means that you expect the audit no-vulnerable-libraries to have a score equal to 1.
Any audit score generated by Lighthouse is between 0 and 1. You can also use the > (greater than) and the < (lower than) operator to evaluate decimal audit scores.
Audit score assertions must be written on separate lines.
Installation
Lighthouse for Azure Pipelines can be installed from the Visual Studio Marketplace.
Available audits
The following audits exist in Lighthouse 5.6.0. They may change with new versions. Execute lighthouse --list-all-audits to discover the available audits for your desired Lighthouse version.
| Audit | Type | Description |
|---|---|---|
| is-on-https | binary | Uses HTTPS |
| redirects-http | binary | Redirects HTTP traffic to HTTPS |
| service-worker | binary | Does not register a service worker that controls page and start_url |
| works-offline | binary | Current page does not respond with a 200 when offline |
| viewport | binary | Has a <meta name="viewport"> tag with width or initial-scale |
| without-javascript | binary | Contains some content when JavaScript is not available |
| first-contentful-paint | numeric | First Contentful Paint |
| first-meaningful-paint | numeric | First Meaningful Paint |
| load-fast-enough-for-pwa | binary | Page load is fast enough on mobile networks |
| speed-index | numeric | Speed Index |
| estimated-input-latency | numeric | Estimated Input Latency |
| total-blocking-time | numeric | Total Blocking Time |
| max-potential-fid | numeric | Max Potential First Input Delay |
| errors-in-console | binary | No browser errors logged to the console |
| time-to-first-byte | binary | Server response times are low (TTFB) |
| first-cpu-idle | numeric | First CPU Idle |
| interactive | numeric | Time to Interactive |
| redirects | numeric | Avoid multiple page redirects |
| installable-manifest | binary | Web app manifest does not meet the installability requirements |
| apple-touch-icon | binary | Does not provide a valid apple-touch-icon |
| splash-screen | binary | Is not configured for a custom splash screen |
| themed-omnibox | binary | Does not set a theme color for the address bar. |
| content-width | binary | Content is sized correctly for the viewport |
| image-aspect-ratio | binary | Displays images with correct aspect ratio |
| deprecations | binary | Avoids deprecated APIs |
| mainthread-work-breakdown | numeric | Minimize main-thread work |
| bootup-time | numeric | Reduce JavaScript execution time |
| uses-rel-preload | numeric | Preload key requests |
| uses-rel-preconnect | numeric | Preconnect to required origins |
| font-display | binary | All text remains visible during webfont loads |
| offline-start-url | binary | start_url does not respond with a 200 when offline |
| third-party-summary | binary | Reduce the impact of third-party code |
| aria-allowed-attr | binary | [aria-*] attributes match their roles |
| aria-required-attr | binary | [role]s do not have all required [aria-*] attributes |
| aria-required-children | binary | Elements with an ARIA [role] that require children to contain a specific [role] have all required children. |
| aria-required-parent | binary | [role]s are contained by their required parent element |
| aria-roles | binary | [role] values are valid |
| aria-valid-attr-value | binary | [aria-*] attributes have valid values |
| aria-valid-attr | binary | [aria-*] attributes are valid and not misspelled |
| button-name | binary | Buttons have an accessible name |
| bypass | binary | The page does not contain a heading, skip link, or landmark region |
| color-contrast | binary | Background and foreground colors do not have a sufficient contrast ratio. |
| document-title | binary | Document has a <title> element |
| duplicate-id | binary | [id] attributes on the page are unique |
| html-has-lang | binary | <html> element has a [lang] attribute |
| html-lang-valid | binary | <html> element has a valid value for its [lang] attribute |
| image-alt | binary | Image elements have [alt] attributes |
| label | binary | Form elements have associated labels |
| link-name | binary | Links do not have a discernible name |
| meta-viewport | binary | [user-scalable="no"] is not used in the <meta name="viewport"> element and the [maximum-scale] attribute is not less than 5. |
| tabindex | binary | No element has a [tabindex] value greater than 0 |
| uses-long-cache-ttl | numeric | Uses efficient cache policy on static assets |
| total-byte-weight | numeric | Avoids enormous network payloads |
| offscreen-images | numeric | Defer offscreen images |
| render-blocking-resources | numeric | Eliminate render-blocking resources |
| unminified-css | numeric | Minify CSS |
| unminified-javascript | numeric | Minify JavaScript |
| unused-css-rules | numeric | Remove unused CSS |
| uses-webp-images | numeric | Serve images in next-gen formats |
| uses-optimized-images | numeric | Efficiently encode images |
| uses-text-compression | numeric | Enable text compression |
| uses-responsive-images | numeric | Properly size images |
| efficient-animated-content | numeric | Use video formats for animated content |
| appcache-manifest | binary | Avoids Application Cache |
| doctype | binary | Page has the HTML doctype |
| dom-size | numeric | Avoids an excessive DOM size |
| external-anchors-use-rel-noopener | binary | Links to cross-origin destinations are safe |
| geolocation-on-start | binary | Avoids requesting the geolocation permission on page load |
| no-document-write | binary | Avoids document.write() |
| no-vulnerable-libraries | binary | Avoids front-end JavaScript libraries with known security vulnerabilities |
| js-libraries | binary | Detected JavaScript libraries |
| notification-on-start | binary | Avoids requesting the notification permission on page load |
| password-inputs-can-be-pasted-into | binary | Allows users to paste into password fields |
| uses-http2 | binary | Uses HTTP/2 for its own resources |
| uses-passive-event-listeners | binary | Does not use passive listeners to improve scrolling performance |
| meta-description | binary | Document does not have a meta description |
| http-status-code | binary | Page has successful HTTP status code |
| font-size | binary | Document uses legible font sizes |
| link-text | binary | Links have descriptive text |
| is-crawlable | binary | Page isn’t blocked from indexing |
| robots-txt | binary | robots.txt is valid |
| tap-targets | binary | Tap targets are not sized appropriately |
| hreflang | binary | Document has a valid hreflang |
| plugins | binary | Document avoids plugins |
Compiling
There are GitHub actions that take care of compiling, packaging and publishing the extension.
License
Copyright © 2023, Groupe GSoft Inc. This code is licensed under the Apache License, Version 2.0. You may obtain a copy of this license at https://github.com/gsoft-inc/azure-pipelines-lighthouse/blob/main/LICENSE.