pytestarch

# Assuming a project structure like: # project_root/ # ├── src/ # │ ├── __init__.py # │ ├── domain/ # │ │ ├── __init__.py # │ │ └── core.py # │ ├── application/ # │ │ ├── __init__.py # │ │ └── service.py # e.g., 'from src.domain import core' # │ └── infrastructure/ # │ ├── __init__.py # │ └── db.py # e.g., 'from src.domain import core' # └── tests/ # └── test_architecture.py # The PYTEST_ARCH_ROOT environment variable MUST be set to the path of your # source code root (e.g., './src') for pytestarch to discover modules correctly. # In tests/test_architecture.py from pytestarch import architectural_rule from pytestarch.patterns import Layer, get_layers def test_layer_dependencies(): # Define the layers in your application. # The first argument to get_layers is the base directory to scan for modules. # The second argument is a list of Layer objects. # Each Layer needs a unique name and a module path regex (e.g., 'src.domain'). layers = get_layers( "src", # Base directory relative to where pytest is run, or an absolute path [ Layer("domain", "src.domain"), Layer("application", "src.application"), Layer("infrastructure", "src.infrastructure"), ] ) # Define architectural rules: # 1. All modules discovered must belong to one of the defined layers. # 2. Layers should not import modules from other layers by default. # 3. Specifically, 'application' and 'infrastructure' layers are allowed # to import *only* from the 'domain' layer. architectural_rule.modules_belong_to_layers(layers) \ .should_not_import_modules_of_other_layers() \ .may_only_import_modules_of_layers("domain") \ .in_layers("application", "infrastructure") \ .check() # To run this test, navigate to your project_root and execute in your terminal: # PYTEST_ARCH_ROOT=./src pytest tests/test_architecture.py