What

External link checking

We use hyperlink to check our links on the compiled website.

It doesn't catch external link problems, since we use the --internal flag.

Removing that flag results in 244 failures that are not surfaced. Some of these appear to be related to our use of the --source-maps flag, which causes issues when running external checks. If we remove THAT flag, the failure list drops to 105.

It'd be good to:

1. Audit and fix all those errors
2. Split external and internal link checking, and run them at different times. We could keep running the internal checks every PR, but only run the external checks manually, or less frequently. We could also look at adjusting our concurrency levels for hyperlink and see if that helps.

"check-links": "npm run check-links:internal && npm run check-links:external",
"check-links:external": "npm run check-links:cli -- --external | tap-mocha-reporter min",
"check-links:internal": "npm run check-links:cli -- --internal --pretty --source-maps | tap-mocha-reporter min",
"check-links:cli": "hyperlink --canonicalroot https://design-system.service.gov.uk/ --recursive deploy/public/sitemap.xml"

Flaky tests

Either hyperlink or tap-mocha-reporter throw out error codes with no obvious output quite frequently, causing our tests to fail.

We should review our use of these tools and see if there's anything else out there. Previously we were using the now defunct metalsmith-broken-link-checker, but @metalsmith-plugins/metalsmith-link-checker is more up to date - but we possibly don't want to stick with a metalsmith-specific solution.

Who needs to work on this

Developer
Content Designer? (in the case that any of the links are dead and we need to find equivalents or reword)

Who needs to review this

Developer

Done when

• Link checking tooling has been audited, and our tests are no longer flaky
• We can run external and internal link checking separately
• Identify broken links
• Fix redirects
• Find alternatives to pages that are gone
• Add external broken link checker