`elixir_test`

Runs ExUnit tests against an elixir_app provider already compiled with mix_env = "test".

Description#

elixir_test depends on exactly one target that provides a complete elixir_app record, such as elixir_library or mix_project. The application must compile with mix_env = "test". During the test action, Once creates a test layout with links to the compiled application and dependency bytecode, then runs the tests without recompiling the application.

That split lets a changed test file rerun tests without recompiling the application. A changed library source invalidates both the compiled library and the dependent test result. By default, tests run through direct ExUnit with elixir, so a package does not need mix.exs. A mix_project dependency selects Mix mode automatically. Once stages declared project, configuration, data, tool, test, and lockfile inputs into an isolated project before running mix test --no-compile --no-deps-check. Library bytecode must already be built by Once in both modes.

Attributes#

Attribute	Type	Required	Default	Description
`mix_config`	string	no	empty	Optional package-relative Mix project file. When omitted, tests run through direct ExUnit without requiring a Mix project
`lockfile`	string	no	`mix.lock`	Package-relative lockfile staged when present
`config`	list<string>	no	`["config/*/.exs"]`	Config file globs included in the test action key
`config_files`	list<string>	no	`[]`	Buck-compatible alias for additional config file globs
`data`	list<string>	no	`[]`	Data file globs available during tests
`os_env`	map<string, string>	no	`{}`	Buck-compatible environment variables exported before running tests
`env_inherit`	list<string>	no	`[]`	Host environment variable names inherited before explicit `env` values
`env`	map<string, string>	no	`{}`	Environment variables exported before running tests
`test_args`	list<string>	no	`[]`	Additional arguments appended to the test runner
`setup_tasks`	list<list<string>>	no	`[]`	Ordered Mix tasks and their exact arguments run before the test task
`elixir_opts`	list<string>	no	`[]`	Bazel-compatible options passed to the direct Elixir interpreter before test files
`setup`	string	no	empty	Shell snippet run after the test environment is prepared and before ExUnit starts
`no_start`	bool	no	`false`	Pass `--no-start` to `mix test` when `mix_config` enables Mix mode
`ez_deps`	list<string>	no	`[]`	Reserved archive dependencies
`tools`	list<string>	no	`[]`	Package-relative executable or support-file globs available to the test setup command
`labels`	list<string>	no	`[]`	Labels exposed through `once_test_info`
`timeout_ms`	int	no	empty	Optional test timeout in milliseconds
`cacheable`	bool	no	`true`	Whether successful test results may be restored from the action cache

A non-empty ez_deps value fails validation because Once cannot place Erlang archives on the ExUnit code path.

elixir_opts applies only to direct ExUnit mode. When mix_config selects Mix mode, use test_args; combining Mix mode with elixir_opts fails validation. setup_tasks also requires Mix mode. Set cacheable = false when setup or the test suite must exercise an external service on every invocation.

Each setup task is an exact argument vector. Do not include the mix executable:

toml

setup_tasks = [
  ["ecto.create", "--quiet", "--no-compile", "--no-deps-check"],
  ["ecto.migrate", "--quiet", "--no-compile", "--no-deps-check"],
]

Dependency Edges#

Edge	Accepts	Description
`deps`	`elixir_app`	The test-environment Elixir application under test

Providers#

The target emits once_test_info.

Capabilities#

Capability	Output groups
`test`	`default`, `test_results`, `logs`

Example#

toml

[[target]]
name = "greeting"
kind = "elixir_library"
srcs = ["lib/**/*.ex"]

[target.attrs]
app_name = "greeting"
mix_env = "test"

[[target]]
name = "greeting_test"
kind = "elixir_test"
srcs = ["test/**/*_test.exs"]
deps = ["./greeting"]

[target.attrs]
labels = ["unit"]