gen-singleton-functions

Installation

go install github.com/mrexox/gen-singleton-functions@latest

Usage

Add the following line in your source code

//go:generate gen-singleton-functions github.com/account/repo/package *MyType

If you want a value receiver then pass a type name without an asterisk

//go:generate gen-singleton-functions github.com/account/repo/package MyType

Example

Make Dog methods Bark and Validate public functions of a package dog.

// dog/dog.go
package dog

import "fmt"

//go:generate gen-singleton-functions github.com/me/animals/dog *Dog
type Dog struct {
    numTails int
    barkingSound string
}

func (d *Dog) Bark() string {
    return d.barkingSound
}

func (d *Dog) Validate() error {
    if d.numTails != 1 {
        return fmt.Errorf("unexpected number of tails: %d", d.numTails)
    }

    return nil
}

After running go generate ./... the resulting file will contain the following:

// dog/dog_gen.go
//
// Code generated by generator, DO NOT EDIT.
//
// This file provides the wrappers for exported methods of a global var `globalDog`.
package dog

var globalDog *Dog

func SetGlobalDog(v *Dog) {
	globalDog = v
}

// Bark calls `globalDog.Bark`.
func Bark() string {
	if globalDog == nil {
		panic("globalDog must be set before calling Bark()")
	}

	return globalDog.Bark()
}

// Validate calls `globalDog.Validate`.
func Validate() error {
	if globalDog == nil {
		panic("globalDog must be set before calling Validate()")
	}

	return globalDog.Validate()
}