Newman vs Pact: What are the differences?

Introduction

In this Markdown code, we will discuss the key differences between Newman and Pact in the context of web development. Newman is a command-line collection runner for Postman, while Pact is a contract testing tool for API integrations. Let's explore the differences between these two tools in more detail.

1. Structure: Newman focuses on running collections of API requests, allowing developers to execute and test APIs in a repetitive manner. On the other hand, Pact focuses on contract testing, where it verifies that the consumer and provider of an API adhere to a shared contract. While Newman tests the implementation of API endpoints, Pact tests the communication and contract between different services.

2. Testing Approach: Newman primarily offers functional testing capabilities by sending requests and verifying responses. It is more focused on individual API endpoints and their behavior. Pact, on the other hand, focuses on defining and verifying contracts between consumer and provider services. It ensures that both sides can interact seamlessly without breaking the contract.

3. Dependency Management: Newman relies on Postman collections to define and execute tests. It requires the endpoints to be set up and running before the tests can be executed. In contrast, Pact provides a way to define the expected requests and responses in a contract file, which can be used by both the consumer and provider independently. This allows each side to test their implementation without dependencies on the other.

4. Versioning and Compatibility: Newman does not have any built-in features for versioning or compatibility management. It primarily focuses on executing API tests without any specific concern for versioning. Pact, however, offers features like consumer-driven contract testing, which enforces compatibility between different versions of APIs. It ensures that changes to the API do not break the contract and affect other services relying on it.

5. Collaboration and Documentation: Newman does not offer many collaborative features apart from sharing Postman collections. It focuses more on the execution of tests rather than collaboration among teams. Pact, on the other hand, provides a mechanism for teams to work together on defining and maintaining contracts. It offers tools for generating human-readable documentation from contract files, aiding in better understanding and collaboration between teams.

6. Integration and Ecosystem: Newman integrates well with Postman and can leverage the extensive ecosystem of Postman for various testing-related tasks. Pact, on the other hand, is independent of any specific ecosystem and can be used with different languages and frameworks. It offers client libraries and plugins for different platforms, allowing seamless integration with various tech stacks.

In summary, Newman is mainly focused on executing collections of API tests while Pact focuses on contract testing and ensuring the compatibility between consumer and provider services, providing collaboration and versioning features along the way.