Prints a list of affected Go packages within a given Git commit range, optionally limiting the results to only packages matching a Go package pattern.
Changes to module dependencies (based on changes to the go.sum file) are also included in this calculation, so if you change a dependency, any packages using that dependency (recursively) will be considered affected. This takes a pessimistic approach: If you update a module, this assumes all packages inside that module may have changed.
This can be useful to decide which executables to build or which tests to run in a large repository. For example, on a branch, you could run this to test only packages which are affected by changes commited on the current branch since it diverged from master:
export GIT_RANGE=$(git merge-base origin/master HEAD)..HEAD
go test $(find-affected-packages $GIT_RANGE)This command must be run from the root of your repository, and the root of the repository must also be where a Go module is defined (go.mod and go.sum must exist there).
find-affected-packages <start commit>..<end commit> [packages...]
Show all affected packages between two commits:
find-affected-packages abc123..def456
Show all affected packages matching ./my-package/...:
find-affected-packages abc123..def456 ./my-package/...