exhaustive checks exhaustiveness of enum switch statements in Go source code.

For the definition of enum and the definition of exhaustiveness used by this program, see godoc. For the changelog, see CHANGELOG in the GitHub wiki. The program can be configured to additionally check exhaustiveness of keys in map literals whose key type is an enum.

Command:

go install github.com/nishanths/exhaustive/cmd/exhaustive@latest

exhaustive [flags] [packages]

For available flags, refer to the Flags section in godoc or run exhaustive -h.

Package:

go get github.com/nishanths/exhaustive

import "github.com/nishanths/exhaustive"

The exhaustive.Analyzer variable follows guidelines in the golang.org/x/tools/go/analysis package. This should make it possible to integrate exhaustive with your own analysis driver program.

Given an enum:

package token // import "example.org/token"

type Token int

const (
	Add Token = iota
	Subtract
	Multiply
	Quotient
	Remainder
)

and code that switches on the enum:

package calc

import "example.org/token"

func x(t token.Token) {
	switch t {
	case token.Add:
	case token.Subtract:
	case token.Remainder:
	default:
	}
}

running exhaustive with default flags will produce:

calc.go:6:2: missing cases in switch of type token.Token: token.Multiply, token.Quotient

Specify flag -check=switch,map to additionally check exhaustiveness of keys in map literals. For example:

var m = map[token.Token]rune{
	token.Add:      '+',
	token.Subtract: '-',
	token.Multiply: '*',
	token.Quotient: '/',
}

calc.go:14:9: missing keys in map of key type token.Token: token.Remainder

Issues and changes are welcome. Please discuss substantial changes in an issue first.