svelte-check-reporter: see svelte-check's errors in GitLab merge requests and GitHub pull requests

[faissalrez]

svelte-check only prints its problems to the CI log, and the svelte-check team prefers not to add output formats. So I wrote svelte-check-reporter, a small CLI that converts --output machine-verbose into:

• a GitLab Code Quality report: new and fixed errors in the merge request widget, markers in the diff
• GitHub Actions annotations: on the workflow run and the pull request diff, nothing to set up
• SARIF for GitHub code scanning: comments on the lines a pull request adds

npm install --save-dev svelte-check-reporter
npx svelte-check --output machine-verbose | npx svelte-check-reporter --format github

It handles .svelte and .ts files, keeps errors and warnings apart, and fails like svelte-check. GitLab and code scanning only report what a change adds or fixes, so a project with existing errors can stop new ones.

See it in the demo's pull requests and merge request. Feedback welcome!