bazel test Command Reference

Run Bazel test targets with the same caching as builds.

bazel test builds and runs test targets, caching results so unchanged tests are not re-run. It is the test driver for any Bazel-based repo.

What it does

bazel test builds the requested test targets and executes them, caching passing results keyed on inputs. Re-running only re-executes tests whose inputs changed, which keeps large suites fast in CI.

Common flags and usage

--test_output=errors|all|streamed: how much test output to print
--test_tag_filters=TAG: include or exclude tests by tag
--runs_per_test=N: rerun to detect flakes
--nocache_test_results: force re-running cached tests
--test_filter=REGEX: run a subset within a target

Example

shell

- name: Test
  run: bazel test --config=ci --test_output=errors //...

In CI

Pass --test_output=errors so failing tests print their logs instead of just a summary. Cached passing results mean only changed tests re-run, so a PR build tests just what it touched.

Key takeaways

bazel test caches passing results; only changed tests re-run.
--test_output=errors prints logs for failing tests in CI.
--runs_per_test and --test_filter help with flakes and subsets.