gowire-example

Overview

This is a demonstration of a Go application that utilizes the Wire framework for dependency injection. The application is an HTTP server that exposes string transformations as an API. It accepts requests with parameters such as /?transform=0&message=hello to perform various string transformations.

Packages

• cmd/hello is the main package which uses other packages and starts a http server
• config is the package to contain individual configs and combined together the whole app configuration
• handlers package contains http handlers
• hello package contains domain specific transform functionality
• server package uses available handlers, configuration to expose a http mux at different end points
• valet package is an example to extend the functionality from hello package

Wire usage

• Wire is employed as a compile-time depenedency generation tool
• Each package contains a wire.go where the injectors are listed
• Each package contains providers and wire Sets
• Using wire, packages can be loosely coupled and easily testable

Package design considerations

• Each type declares the interfaces that it depends on and also describes its own behaviour with an interface
• If the dependency is known, it goes as property. If it not known then as a functon argument. The type's dependencies are provided by wire
• Keep dependencies to only what are required

Notes

• Consider good(simple and clear) APIs
• Prefer smaller packages
• Use composition to express clean requirements
• Recheck and verify the generated wire injectors

References

• https://github.com/google/wire
• https://go.dev/blog/wire
• https://github.com/google/wire/tree/main/docs
• https://en.wikipedia.org/wiki/SOLID

PRs are welcome

• Thank you