Job summaries are Markdown files generated by GitHub Actions and displayed on the summary page of each job.
Note
This behavior is slightly different from what happens on GitHub Actions
runners. If the file referenced by GITHUB_STEP_SUMMARY does not exist, the
workflow run will fail with an error like the following:
Unable to access summary file: '/path/to/summary'.
However, GitHub Actions normally creates this file for you, so functionally you should not see a difference 😊
When testing with local-action, you can output the summary for your action to
a file. Just set the GITHUB_STEP_SUMMARY environment variable in your
.env file. If the summary file does not exist, it will be
created.
GITHUB_STEP_SUMMARY="/path/to/summary.md"Warning
If your action calls core.summary.write() and no value is set for this
environment variable, the action will fail!