pytest_test

Python tests run with pytest.

Start Here

The selected python interpreter must be able to import pytest. When the attribute is omitted, Once first uses .venv/bin/python or the Windows virtual environment equivalent when present, then tries python3 and python on the executable search path. You can also set an absolute or workspace-relative path explicitly. A common direct installation is:

python3 -m pip install pytest

Retrieve the runnable starter when you want a complete declaration and sample tests:

once query example pytest_test pytest-test-minimal --format json

Copy the declaration below into once.toml, adjust srcs for the project, then establish discovery and run the file batches:

once test tests --format json
once query test-manifest tests --format json
once test tests --jobs 4 --format json

The first command runs the complete target. Later runs can use the resulting manifest for automatic batching and exact selection. See Testing and Scheduling for affected plans, case-level batching, and exact unit commands.

Description

pytest_test invokes pytest through the selected Python interpreter, records stable node identifiers, and writes normalized Once results. A complete run discovers cases for exact interactive execution and automatic scheduling.

Automatic batching uses one batch per test file by default. Set batching to case for one batch per discovered case, or target to keep one batch for the target. A missing or stale manifest runs the whole target once before Once uses smaller batches.

Attributes

Attribute	Type	Required	Default	Description
python	string	no	automatic	Python interpreter name, absolute path, or workspace-relative path that can import pytest
config	list<string>	no	pyproject.toml, pytest.ini, conftest.py	Configuration and collection inputs
data	list<string>	no	[]	Runtime data inputs read by tests
args	list<string>	no	[]	Additional pytest arguments
env	map<string, string>	no	{}	Explicit test environment variables
env_inherit	list<string>	no	[]	Host environment variables inherited by name
batching	string	no	file	Automatic granularity: file, case, or target
labels	list<string>	no	[]	Labels exposed through test discovery
timeout_ms	int	no	empty	Optional timeout in milliseconds

Dependency Edges

deps names targets whose changes should select this test target.

Providers and Capabilities

The target emits once_test_info and exposes test with the default, test_results, and logs output groups.

Example

[[target]]
name = "tests"
kind = "pytest_test"
srcs = ["tests/**/*.py"]

[target.attrs]
python = ".venv/bin/python"
labels = ["unit"]

Declare fixtures, configuration, and runtime files through srcs, config, or data so they participate in caching and manifest freshness.