rules_pytest

Bazel rules for the Pytest Python test framework.

Rules

• py_pytest_test
• py_pytest_test_suite
• py_pytest_toolchain

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current_py_pytest_toolchain

current_py_pytest_toolchain(name)

A rule for exposing the current registered py_pytest_toolchain.

ATTRIBUTES

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required

py_pytest_toolchain

py_pytest_toolchain(name, pytest)

A toolchain for the pytest formatter rules.

ATTRIBUTES

Name	Description	Type	Mandatory	Default
name	A unique name for this target.	Name	required
pytest	The pytest py_library to use with the rules.	Label	required

py_pytest_test

py_pytest_test(name, srcs, coverage_rc, pytest_config, numprocesses, tags, kwargs)

A rule which runs python tests using pytest as the py_test test runner.

This rule also supports a build setting for globally applying extra flags to test invocations. Users can add something similar to the following to their .bazelrc files:

build --//python/pytest:extra_args=--color=yes,-vv

The example above will add --colors=yes and -vv arguments to the end of the pytest invocation.

Tips:

• It's common for tests to have some utility code that does not live in a test source file. To account for this. A py_library can be created that contains only these sources which are then passed to py_pytest_test via deps.

load("@rules_python//python:defs.bzl", "py_library")
load("@rules_pytest//python/pytest:defs.bzl", "PYTEST_TARGET", "py_pytest_test")

py_library(
    name = "test_utils",
    srcs = [
        "tests/__init__.py",
        "tests/conftest.py",
    ],
    deps = [PYTEST_TARGET],
    testonly = True,
)

py_pytest_test(
    name = "test",
    srcs = ["tests/example_test.py"],
    deps = [":test_utils"],
)

PARAMETERS

Name	Description	Default Value
name	The name for the current target.	none
srcs	An explicit list of source files to test.	none
coverage_rc	The pytest-cov configuration file to use	Label("@rules_pytest//python/pytest:coverage_rc")
pytest_config	The pytest configuration file to use	Label("@rules_pytest//python/pytest:config")
numprocesses	If set the pytest-xdist argument --numprocesses (-n) will be passed to the test.	None
tags	Tags to set on the underlying py_test target.	[]
kwargs	Keyword arguments to forward to the underlying py_test target.	none

py_pytest_test_suite

py_pytest_test_suite(name, tests, args, data, coverage_rc, pytest_config, kwargs)

Generates a test_suite which groups various test targets for a set of python sources.

Given an idiomatic python project structure:

BUILD.bazel
my_lib/
    __init__.py
    mod_a.py
    mod_b.py
    mod_c.py
requirements.in
requirements.txt
tests/
    __init__.py
    fixtures.py
    test_mod_a.py
    test_mod_b.py
    test_mod_c.py

This rule can be used to easily define test targets:

load("@rules_python//python:defs.bzl", "py_library")
load("@rules_pytest//python/pytest:defs.bzl", "py_pytest_test_suite")

py_library(
    name = "my_lib",
    srcs = glob(["my_lib/**/*.py"])
    imports = ["."],
)

py_pytest_test_suite(
    name = "my_lib_test_suite",
    # Source files containing test helpers should go here.
    # Note that the test sources are excluded. This avoids
    # a test to be updated without invalidating all other
    # targets.
    srcs = glob(
        include = ["tests/**/*.py"],
        exclude = ["tests/**/*_test.py"],
    ),
    # Any data files the tests may need would be passed here
    data = glob(["tests/**/*.json"]),
    # This field is used for dedicated test files.
    tests = glob(["tests/**/*_test.py"]),
    deps = [
        ":my_lib",
    ],
)

For each file passed to tests, a py_pytest_test target will be created. From the example above, the user should expect to see the following test targets:

//:my_lib_test_suite
//:tests/test_mod_a
//:tests/test_mod_b
//:tests/test_mod_c

Additional Notes:

• No file passed to tests should be passed found in the srcs or data attributes or tests will not be able to be individually cached.

PARAMETERS

Name	Description	Default Value
name	The name of the test suite	none
tests	A list of source files, typically glob(["tests/**/*_test.py"]), which are converted into test targets.	none
args	Arguments for the underlying py_pytest_test targets.	[]
data	A list of additional data for the test. This field would also include python files containing test helper functionality.	[]
coverage_rc	The pytest-cov configuration file to use.	Label("@rules_pytest//python/pytest:coverage_rc")
pytest_config	The pytest configuration file to use.	Label("@rules_pytest//python/pytest:config")
kwargs	Keyword arguments passed to the underlying py_test rule.	none