Development

Gazelle extensions are written in Go.

See the Gazelle documentation for more information on extending Gazelle.

Dependencies

If you add new Go dependencies to the plugin source code, you need to “tidy” the go.mod file. After changing that file, run go mod tidy or bazel run @go_sdk//:bin/go -- mod tidy to update the go.mod and go.sum files. Then run bazel run //:gazelle_update_repos to have gazelle add the new dependencies to the deps.bzl file. The deps.bzl file is used as defined in our /WORKSPACE to include the external repos Bazel loads Go dependencies from.

Then after editing Go code, run bazel run //:gazelle to generate/update the rules in the BUILD.bazel files in our repo.

Tests

See also

gazelle/python/testdata/README.md

To run tests, cd into the gazelle directory and run bazel test //....

Test cases are found at gazelle/python/testdata. To make a new test case, create a directory in that folder with the following files:

• README.md with a short blurb describing the test case(s).

• test.yaml, either empty (with just the docstart --- line) or with the expected stderr and exit codes of the test case.

• and empty WORKSPACE file

You will also need BUILD.in and BUILD.out files somewhere within the test case directory. These can be in the test case root, in subdirectories, or both.

• BUILD.in files are populated with the “before” information - typically things like Gazelle directives or pre-existing targets. This is how the BUILD.bazel file looks before running Gazelle.

• BUILD.out files are the expected result after running Gazelle within the test case.

Tip

The easiest way to create a new test is to look at one of the existing test cases.

The source code for running tests is gazelle/python/python_test.go.