pytest-variables

3.1.0 · active · verified Tue Apr 14

pytest-variables is a plugin for pytest that provides a mechanism to supply external variables to tests and fixtures. It allows defining variables in various file formats (JSON, YAML, TOML, HJSON) and making them accessible as a dictionary fixture within your pytest test suite. The current version is 3.1.0, and it follows a regular release cadence with major versions indicating breaking changes.

Warnings

breaking Version 3.1.0 dropped support for Python 3.7. Ensure your project uses Python 3.8 or newer.
Fix: Upgrade Python to 3.8+ or pin `pytest-variables` to `<3.1.0`.
breaking Version 3.0.0 switched internal variable storage from `_variables` to `pytest.stash`. While not a public API, direct access to `_variables` will break.
Fix: Avoid directly accessing internal plugin attributes. Use the `variables` fixture for all variable access.
gotcha When multiple `--variables` files are specified, later files in the command line override values from earlier files if duplicate keys are encountered (for non-dictionary values). For dictionaries, they are merged.
Fix: Be mindful of the order when specifying multiple variable files. Place more specific or overriding configurations later in the command-line argument list.
gotcha If using YAML files, the `yaml_loader` can be configured in `pytest.ini`. The loader name (e.g., `BaseLoader`, `SafeLoader`, `FullLoader`, `UnsafeLoader`) is case-sensitive. The default is `FullLoader`.
Fix: Verify the `yaml_loader` setting in `pytest.ini` (e.g., `[pytest] yaml_loader = SafeLoader`) matches the expected case and loader type if encountering YAML parsing issues.

Install

pip install pytest-variables Base Installation
pip install pytest-variables[hjson] With HJSON support
pip install pytest-variables[yaml] With YAML support
pip install pytest-variables[toml] With TOML support

Imports

variables
```
def test_example(variables):
```
The 'variables' fixture is automatically discovered and injected by pytest; no explicit Python import statement for 'variables' is needed in test files.

Quickstart

Create a variable file (e.g., `variables.json`) and then use the `--variables` command-line option with pytest. The variables will be available as a `variables` fixture in your tests. Environment variables can be used as fallbacks within the variable files.

# content of variables.json
{
  "base_url": "https://api.example.com",
  "api_key": "${API_KEY:default_key}"
}

# content of test_api.py
def test_api_endpoint(variables):
    assert variables['base_url'] == 'https://api.example.com'
    assert variables['api_key'] is not None
    # Example of accessing an environment variable fallback:
    import os
    expected_api_key = os.environ.get('API_KEY', 'default_key')
    assert variables['api_key'] == expected_api_key

# To run: pytest --variables variables.json
# You can also pass multiple files: pytest --variables file1.json --variables file2.yaml

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