API testing is a crucial aspect of modern software development, ensuring that APIs function correctly, remain reliable, and maintain backward compatibility. At AOE, we have adopted API testing as a standard practice for all projects that expose or consume APIs.
API Tests in Code
Embedding API tests directly into your codebase provides many benefits:
- Version control: Tests evolve alongside the API implementation
- Automated validation: Immediate feedback on API changes that might break contracts
- Documentation: Tests serve as executable documentation for API behavior
- Regression prevention: Early detection of unintended changes in API behavior
We recommend writing API tests at multiple levels:
API Testing Tools
Several tools have proven particularly valuable for API testing:
Bruno
Bruno is an open-source API client that emphasizes a developer-friendly approach to API testing. Its key advantages include:
- Git-friendly collections stored in Markdown/JSON format
- Local-first workflow with no accounts or collections within any cloud required
- Supports complex environments and variable management
- Scriptable request pre/post processors
- Collection runner for executing test suites
Other options
There are also many other good solutions like Postman, Insomnia etc.
CI/CD Integration
A critical aspect of API testing is integrating tests into our CI/CD pipelines. Most of API testing tools provide a CLI tool to run collections from the commandline.
These integrations allow for:
- Automated API validation in CI/CD pipelines
- Pre-deployment verification
- Scheduled testing for continuous monitoring
- Integration with test reporting systems