Carthage vs SPM: What are the differences?

Introduction

When it comes to managing dependencies in iOS projects, Carthage and Swift Package Manager (SPM) are two popular choices among developers. Both tools offer different approaches to dependency management, each with its own set of advantages and limitations.

1. Integration with Xcode: One key difference between Carthage and SPM is how they integrate with Xcode. Carthage uses Xcode project files to link prebuilt frameworks, which means you have to manually manage the project configuration. On the other hand, SPM generates an Xcode workspace and handles dependency resolution and building automatically, providing a more streamlined integration experience.

2. Dynamic vs. Static Frameworks: Carthage primarily supports dynamic frameworks, which are loaded at runtime, while SPM focuses on static frameworks that are compiled directly into the application binary. This difference can impact how dependencies are packaged and distributed, as well as the performance of the final application.

3. Versioning and Updates: Carthage allows for more flexibility in specifying dependency versions, as it relies on Git tags for versioning. This can be useful for projects with specific version requirements. SPM, on the other hand, follows the semantic versioning approach and automatically fetches the latest compatible version of dependencies. This can make updating dependencies easier but may lead to compatibility issues.

4. Community and Ecosystem: Carthage has been around longer than SPM and has a larger and more mature ecosystem of third-party libraries and tools. However, SPM is the officially supported dependency management tool by Apple and is gaining popularity among developers. The choice between the two may depend on the specific dependencies you need for your project.

5. Binary Compatibility: Carthage does not guarantee binary compatibility between versions, which means you may need to recompile dependencies when switching between versions. SPM, on the other hand, enforces binary compatibility between minor versions, reducing the risk of breaking changes when updating dependencies.

6. Build Performance: Carthage builds dependencies from source every time you update or add a new dependency, which can lead to longer build times. SPM caches dependencies and only rebuilds them when necessary, resulting in faster build times overall. This difference in build performance can impact developer productivity and iteration speed.

In Summary, the key differences between Carthage and Swift Package Manager include their integration with Xcode, support for dynamic vs. static frameworks, versioning and updates, community ecosystem, binary compatibility, and build performance. Developers can choose the tool that best fits their project requirements and preferences.