httpmock

Provides a chainable, intuitive API for defining mocks, as shown in the example with `when.method(GET).path(...).query_param(...)`, making test code readable and maintainable.

Built-in support for regex, JSON, cookies, and custom matchers allows precise control over mock expectations, reducing false positives in complex tests.

Can run as a separate mock server with an official Docker image, enabling integration testing across services or in CI/CD pipelines without code changes.

Features like network delay simulation and detailed error diffs help test application resilience and debug mismatched requests efficiently, as highlighted in the verification tools.