Cache invalidation is one of the most complex computer science tasks. Especially so for GitHub action workflows since there is no embedded mechanism to clean or invalidate present caches. However, what we can do is to update cache keys with a dedicated environment variable of the workflow or repository secret.

Let's learn how to extend existent Pull Request Update GitHub Actions workflow with steps specific for Dependabot pull requests (i.e. labels). We will add two jobs to the existent pull_request workflow and experiment with separate before and after workflow_run event workflows. Fortunately, after the recent GitHub actions update we don't need to use a separate pull_request_target event workflow as a workaround.

GitHub Actions is an awesome and very powerful tool. Let's explore workflow running time optimizations with caching node_modules and production build artifacts. We will be using Dependency Cache GH Actions feature driven by actions/cache. Hint: as always, cache invalidation is a key.