what-changed

Action looks at changed files since last successful workflow run and determines what changed.

The action takes a list of file paths as input, and outputs a string as follows:

• only-inputs: true if only files in the input list changed
• non-inputs: true if only files outside the input list changed
• both: true if both files in the input list and outside the input list changed

Inputs

The action takes two inputs, one of which is required:

• files: A comma-separated list of file paths to check for changes. The list supports recursive glob patterns including hidden files and directories. Required.
• main-branch-name: The name of the main branch. Optional, default is main.

How does it work

First, we use nrwl/nx-set-shas to determine the BASE and HEAD of the change set. We then compare the list of files changed between BASE and HEAD with the list of files provided as input.

If the list of changed files is a subset of the input list, we output only-inputs. If the list of changed files is disjoint from the input list, we output non-inputs. Otherwise, we output both.

For developers

Most of the action is in what_changed.py, but this script is embedded in the composite workflow in action.yaml. In order to update the action, run mise run build.

It is recommended to install a pre-commit hook to ensure that the action is built before committing changes. You can use mise run install-pre-commit to install the hook.