Feature Request: Handle Identical Base/Head SHAs In Tj-actions
Hey everyone! Today, we're diving into a feature request for the tj-actions/changed-files GitHub Action that aims to improve its handling of scenarios where the base and head SHAs are the same. This is a situation that can occur in pipelines, and currently, it leads to an error. Let's explore the problem, the proposed solution, and the alternatives.
The Issue: Error When Base and Head SHAs Match
So, the main problem we're tackling here is that the tj-actions/changed-files action throws an error when the inputs.base_sha and inputs.sha are identical. Imagine a scenario in your pipeline where this is expected – maybe there were no actual changes in a commit. In such cases, you might want the action to simply return an empty result rather than halting the workflow with an error. This is crucial for maintaining smooth and predictable pipeline executions.
The current behavior can be a bit of a roadblock. When the action raises an error, it forces you to implement workarounds to handle this specific case. This not only adds complexity to your workflow but also makes it less clean and straightforward. We want to avoid these unnecessary detours and make the action more adaptable to different situations.
To give you a clearer picture, consider a workflow that automatically triggers on every push to a repository. Sometimes, these pushes might not include any actual code changes – perhaps just updates to documentation or configuration files that don't affect the core codebase. In these instances, the base and head SHAs could be the same. If we want our workflow to gracefully handle these situations without errors, we need a way to tell the tj-actions/changed-files action to chill out and return an empty result instead of throwing a fit.
This is particularly important for teams that strive for continuous integration and continuous delivery (CI/CD). A robust CI/CD pipeline should be able to handle various scenarios without breaking, and that includes cases where no code changes are present. By addressing this issue, we can make the tj-actions/changed-files action a more reliable and versatile tool in our CI/CD arsenal.
Proposed Solution: Option to Prevent Error
The suggested solution is pretty straightforward: let's add an option to the tj-actions/changed-files action that allows us to control its behavior when the base and head SHAs are the same. This could be a simple flag, like raise_error_on_identical_sha, which defaults to true to maintain existing behavior but can be set to false to prevent the error.
With this flag in place, you'd have the flexibility to decide what happens when the SHAs match. If you set raise_error_on_identical_sha: false, the action would simply return an empty result, allowing your workflow to continue without interruption. This gives you more control and makes the action more adaptable to different use cases.
Think of it as adding a safety valve to the action. When things are normal, it works as expected. But when the pressure builds up (i.e., identical SHAs), you can open the valve and let the pressure release (i.e., return an empty result). This kind of flexibility is what makes tools truly powerful and user-friendly.
This approach also aligns with the principle of least surprise. By default, the action would continue to behave as it always has, ensuring that existing workflows aren't broken. But for those who need the new behavior, the option is there, ready to be used. It's a win-win situation for everyone involved.
Current Workaround: A Glimpse into the Trenches
Right now, if you're facing this issue, you're likely using a workaround similar to the one shared in the feature request. This involves checking if the base and head commit results are different and then conditionally running the tj-actions/changed-files action. If they're the same, you manually set the output to an empty string.
Here’s a snippet of the workaround:
- uses: tj-actions/changed-files@24d32ffd492484c1d75e0c0b894501ddb9d30d62
id: changed-files-base
if: ${{ steps.extract_base_commit.outputs.result != steps.extract_head_commit.outputs.result }}
with:
base_sha: ${{ steps.extract_base_commit.outputs.result }}
sha: ${{ steps.extract_head_commit.outputs.result }}
write_output_files: true
separator: "\n"
# if base and head commit are the same tj-actions/changed-files action raises an error, so we need to handle it
- name: Get changed files
id: changed-files
run: |
if [ steps.extract_base_commit.outputs.result != steps.extract_head_commit.outputs.result ]; then
echo "all_changed_files=$(cat ${changed_files_base})" >> $GITHUB_OUTPUT
else
echo "all_changed_files=" >> $GITHUB_OUTPUT
fi
env:
changed_files_base: ${{ steps.changed-files-base.outputs.all_changed_files }}
While this workaround gets the job done, it's not ideal. It adds extra steps and complexity to your workflow, making it harder to read and maintain. It also introduces a bit of redundancy, as you're essentially reimplementing some of the logic that the tj-actions/changed-files action already provides.
Moreover, this workaround can be a bit fragile. If the internal workings of the tj-actions/changed-files action change in the future, your workaround might break. This means you'd have to revisit your workflows and update them, which is never a fun task.
By adding an option to handle identical SHAs directly within the action, we can eliminate the need for this workaround. This would simplify workflows, reduce complexity, and make the action more robust and reliable.
Alternatives Considered: Exploring the Landscape
Before settling on the proposed solution, it's always a good idea to explore alternatives. In this case, one alternative might be to simply document the current behavior and encourage users to handle the error in their workflows. However, this approach puts the burden on the user and doesn't address the underlying issue, so it is not ideal.
Another alternative could be to automatically return an empty result when the SHAs are the same, without providing an option to change this behavior. While this would simplify things, it might not be suitable for all use cases. Some users might actually want the error to be raised, as it could indicate a problem in their workflow configuration.
That's why providing an option, like the raise_error_on_identical_sha flag, is the best approach. It gives users the flexibility to choose the behavior that best suits their needs, without forcing a particular solution on everyone.
By carefully considering these alternatives, we can ensure that the chosen solution is the most effective and user-friendly option. It's all about finding the right balance between simplicity, flexibility, and robustness.
The Takeaway: A More Flexible Future for tj-actions/changed-files
In conclusion, adding an option to prevent errors when the base and head SHAs are the same in the tj-actions/changed-files action would be a significant improvement. It would simplify workflows, reduce complexity, and make the action more adaptable to different scenarios. By providing this flexibility, we can empower users to build more robust and reliable CI/CD pipelines.
This feature request highlights the importance of listening to user feedback and continuously improving our tools. By addressing this issue, we can make the tj-actions/changed-files action an even more valuable asset in the developer community. So, let's hope this feature gets implemented soon, making our lives a little bit easier!