nomnom

nomnom is a code generator for Go enums that produces readable, tested, and performant code. See fixtures for examples of generated code.

Installation

Minimum Go version: Go 1.16

Use go get to install and update:

go get -u github.com/rickypai/nomnom

Basic Usage

nomnom -w -t [file with go enums]

Motivation

Custom types and constants are often used in Go for defining enums:

type ProgrammingLanguage string

const (
	ProgrammingLanguageGo        ProgrammingLanguage = "Go"
	ProgrammingLanguageJava      ProgrammingLanguage = "Java"
	ProgrammingLanguageBrainfuck ProgrammingLanguage = "Brianfuck"
)

This allows type safety when using those values:

type Project struct {
  ImplementedLanguage ProgrammingLanguage
}

var newProject = Project{
  ImplementedLanguage: "Japanese", // will not compile
}

However, it's possible to get around these restrictions:

var newProject = Project{
  ImplementedLanguage: ProgrammingLanguage("Singlish"), // compiles but not a proper enum value
}

While it's possible to write functions to check against possible values, it can be cumbersome when there are many possible enum values:

func IsProgrammingLanguage(in string) bool {
	switch in {
	case "Go":
		return true
	case "Java":
		return true
	case "Brainfuck":
		return true
	}

	return false
}

Furthermore, we'd have to create new checker functions for each type.

nomnom strives to make this usage pattern more maintainable by generating helper functions from existing enum definitions. It also generates unit tests for the generated functions. See fixtures for examples of generated helper functions and their corresponding tests.