mustify

mustify is CLI tool for generate MustXXX methods from go source which includes methods that return error.

In Go, there is a culture where a method that occur a panic instead of returning an error has Must as a prefix.
For example, regexp.MustCompile is the wrapper for regexp.Compile which occure panic if regexp.Compile return error. mustify generate the wrapper automatically from all functions which return error.

Usage

mustify [path]

Assume you have below functions in math.go

package lib

import (
	"errors"
	"math"
)

// Sqrt returns the square root of x
func Sqrt(x float64) (float64, error) {
	if x < 0 {
		return 0, errors.New("invalid value")
	}
	return math.Sqrt(x), nil
}

// Sqrt returns the square root of x without error
func SqrtWithoutError(x float64) float64 {
	return math.Sqrt(x)
}

// SumAndSub returns sum and sub of arguments
func SumAndSub(v1, v2 int) (int, int, error) {
	return v1 + v2, v1 - v2, nil
}

func unexportedFunc() error {
	return nil
}

Then execute mustify:

$ mustify math.go > must-math.go
$ cat lib/must-math.go
package lib

// MustSqrt returns the square root of x
func MustSqrt(x float64) float64 {
	_v0, _err := Sqrt(x)
	if _err != nil {
		panic(_err)
	}
	return _v0
}

// MustSumAndSub returns sum and sub of arguments
func MustSumAndSub(v1, v2 int) (int, int) {
	_v0, _v1, _err := SumAndSub(v1, v2)
	if _err != nil {
		panic(_err)
	}
	return _v0, _v1
}