github-workflows

GitHub Actions CI/CD pipelines automate testing and deployment by defining workflows in YAML files that trigger on events like pushes or pull requests. Start by creating a .github/workflows directory, add a workflow file, specify triggers and jobs, then commit to activate the pipeline.

GitHub Actions triggers are events that start workflows: push runs on code commits, pull_request on PR creation, schedule runs on a cron timer, and workflow_dispatch enables manual activation. Choose triggers based on when you need automation—push for every commit, schedule for recurring tasks, workflow_dispatch for on-demand runs.

Debug workflow failures by enabling verbose logging in your runner, reviewing the workflow logs in the Actions tab, and checking job step outputs for error details. Add debugging steps to inspect environment variables and file states before failures occur.

Yes, use matrix strategies in GitHub Actions to test across multiple OS and runtime versions simultaneously. Define a matrix object with os and node-version arrays, and Actions generates parallel jobs for each combination, reducing total run time.

Optimize workflows by caching dependencies to avoid re-downloading, using artifact management to pass data between jobs, and configuring path filtering in monorepos to run jobs only when relevant files change. These techniques reduce build time and runner costs.

Use the actions/cache action to cache dependencies like npm packages between runs, and actions/upload-artifact to store build outputs for download or passing to downstream jobs. Both reduce redundant work and speed up pipelines.