SwiftMock

SwiftMock is a command-line tool designed for developers working with Swift who need to automate the creation of mock implementations for Swift protocols. By marking protocols with a special annotation, users can have SwiftMock scan their source files and generate production-ready mocks, eliminating the repetitive and error-prone process of writing and maintaining mocks manually. This tool addresses the challenges of boilerplate code, ensuring that mocks stay in sync with protocol changes and freeing developers to focus on writing tests rather than mock code.

Key features of SwiftMock include automatic call tracking for every method in a protocol, argument capture for inspecting values passed to methods, and customizable handlers that allow users to define behavior, return values, throw errors, or trigger side effects. The tool supports async methods, throwing functions, and complex return types. SwiftMock also provides incremental builds with smart caching to skip regeneration when source files have not changed, which can speed up continuous integration builds. Output can be customized so that all mocks are generated in a single file or separated into individual files per protocol, depending on project organization preferences.

SwiftMock integrates with Xcode by allowing users to add it to build phases, ensuring that mocks are automatically regenerated whenever protocols change. 1 and macOS 13 or later. Installation is available via the Swift Package Manager or by building from source. The tool is distributed under the MIT License, making it open source.

As a solution for automated mock generation in Swift, SwiftMock aims to streamline comprehensive unit testing by providing features such as public access for cross-module testing, type-safe customizable handlers, and fatal error handling if a handler is not set. Its flexible command-line options let users tailor the tool to their specific workflow and project structure.