Test

rx test runs your tests with the best available runner (nextest when installed) and can restrict the run to packages affected by a change.

Basic usage

rx test                          # run all tests
rx test --release                # test in release mode
rx test -- --nocapture           # pass flags to the test harness
rx test -- test_name             # run a specific test

Test runner selection

rx selects the test runner based on your rx.toml configuration:

[test]
runner = "auto"      # use nextest if installed, else cargo test
runner = "nextest"   # always use cargo-nextest
runner = "cargo"     # always use cargo test
extra_args = []      # extra args passed to every test run

With "auto", rx checks for cargo-nextest on the PATH and uses it when available. nextest provides better output formatting, per-test timeouts, and parallel execution.

Affected-only testing

Only test packages that have changed since a base ref:

rx test --affected                # changed since HEAD~1
rx test --affected --base main    # changed since main branch
rx test --affected --base v1.0    # changed since a tag

rx maps changed files from git diff to workspace members, expands the set to transitive dependents (a change in core also affects everything that depends on it), and runs one test invocation with repeated -p selections. If nothing relevant changed, the run is skipped.

--affected also works on rx ci and any task: rx ci --affected, rx run lint --affected. Shell tasks receive the selection as RX_AFFECTED_PACKAGES.

Related commands

• rx ci – run the full pipeline (includes tests)