bahmutov / changed-cy-tests

Example GitHub Action running changed Cypress specs against master first, then all the tests

changed-cy-tests

Example GitHub Action running changed Cypress specs against master first, then all the tests

Inspired by Jest and the --changedSince flag in GitHub Actions CI

Example pull request #2 with just changed file spec-b.js. The GitHub workflow .github/workflows/ci.yml determines that this file has changed against the master branch and first runs just this spec. If that passes, then it runs ALL specs.

We determine the changed Cypress specs using the following git command (after checking out both head and base branches)

git diff --name-only \
  origin/${{ github.base_ref }} origin/${{ github.head_ref }} -- cypress/integration

Then if this returns something we can use cypress run --spec ... to run the changed specs first.

CHANGED_SPECS=$(git diff --name-only origin/${{ github.base_ref }} origin/${{ github.head_ref }} -- cypress/integration)
if [ -n "$CHANGED_SPECS" ]; then
  echo "Running the following changed specs"
  echo $CHANGED_SPECS
  npx cypress run --spec $CHANGED_SPECS
fi

And after that we can run all specs using Cypress GitHub Action

The combination of fail fast on the changed specs + run all specs afterwards feels good.

Cypress Dashboard

changed-cy-tests's Issues

Unnecessary checkout

I don't think these lines

changed-cy-tests/.github/workflows/ci.yml

Lines 15 to 19 in 3905af5

	# get the actual source for two branches
	git checkout origin/${{ github.base_ref }}
	git checkout origin/${{ github.head_ref }}
	# get back to the merge commit
	git checkout ${{ github.sha }}

are needed, the git fetch lines are enough to then be able to do perform the diff and to get the changed files which are all that's needed further down.

Happy to raise a PR if there isn't something I'm missing here?

Thanks for these and the accompanying blog post - really really useful!