Conftest

Conftest is a term that commonly refers to two related concepts used in software testing and configuration validation: a command-line policy testing tool and a special configuration file for the pytest framework.

Conftest (tool) is an open-source CLI utility that uses the Open Policy Agent (OPA) Rego language to write and evaluate policies against structured configuration files such as YAML, JSON, and Terraform plans. It is frequently used in CI/CD pipelines to enforce security, compliance, and best-practice checks on Kubernetes manifests, Helm charts, and other infrastructure-as-code artifacts. Users write Rego policies, then run conftest to test configuration files and produce pass/fail results or human-readable diagnostics. The tool is valued for its declarative policy language, lightweight integration, and suitability for automated validation.

conftest.py (pytest) is a special Python module recognized by the pytest test runner. Placed in a test directory, it provides fixtures, hooks, and configuration that apply to tests in that directory and its subdirectories. conftest.py enables sharing setup code without creating a separate plugin, supports fixture scopes and autouse fixtures, and can register custom pytest hooks. It is discovered automatically by pytest and is not intended to be imported directly by test modules.

Because the two meanings are distinct—one a standalone policy-testing tool and the other a pytest configuration file—context determines which "conftest" is being referenced.