implgen

README

implgen

implgen is a developer utility designed to automatically generate boilerplate implementations for Go interfaces. It helps kick-start the development of service layers, adapters, and stubs while saving time and reducing manual effort.

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Overview

implgen provides some fetures:

• 🛠 Generate empty implementations of interfaces
• 📂 Supports single-file or per-method file output
• 📦 Customizable output package and struct name
• 🎯 Target a specific interface or process all in the source file
• 🐫 Automatic file/folder naming via kebab-case and snake_case converters

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🚀 Installation

go install github.com/not-for-prod/implgen@latest

Usage example

implgen --src=./service --dst=./serviceimpl --interface-name=Greeter

Flags (required):

• src - source file path
• dst - destination dir path

Flags (optional):

• interface-name - source interface name
• impl-name - generated implementation struct name
• impl-package - generated implementation package name, can be used only if interface-name set
• enable-trace - enables writing otel.Traсer(...).Start(...) in methods,

Assume you have an interface:

type TestInterface interface {
    A(ctx context.Context, req dto.GoRequest) error
    B(ctx context.Context, req map[dto.GoRequest]dto.GoRequest) error
    C(ctx context.Context, req []dto.GoRequest) error
    D(ctx context.Context, req int, opts ...dto.GoRequest) error
}

Run:

implgen --src example/in/interface.go \
		--dst example/out/ \
		--interface-name TestInterface \
		--impl-name Test \
		--impl-package test

This will generate:

• A struct with name Test with method stubs

See dst example for more details