How to Use the Environment Variable Reporter

The EnvironmentVariableReporter lets you select a reporter without changing any test code, by setting the APPROVAL_TESTS_USE_REPORTER environment variable.

Basic Usage

Set the environment variable to a fully-qualified class name before running your tests:

export APPROVAL_TESTS_USE_REPORTER=approvaltests.reporters.diff_tools.ReportWithVisualStudioCode
python -m pytest

On Windows:

$env:APPROVAL_TESTS_USE_REPORTER = "approvaltests.reporters.diff_tools.ReportWithVisualStudioCode"
python -m pytest

Use Cases

• Personal preferences: each developer uses their preferred diff tool without touching shared test code.
• CI environments: configure a CI-appropriate reporter (e.g. one that prints diffs to stdout) via an environment variable in the pipeline config.
• Switching reporters across test runs: toggle between reporters without editing code.
• AI: can use reporters suited to console output.