gopls/internal/analysis/maprange/testdata/basic.txtar

Test of fixing redundant calls to maps.Keys and maps.Values
(both stdlib "maps" and "golang.org/x/exp/maps") for Go 1.24.

-- go.mod --
module maprange

require golang.org/x/exp v0.0.0

replace golang.org/x/exp => ./exp

go 1.24

-- basic.go --
package basic

import "maps"

func _() {
	m := make(map[int]int)

	for range maps.Keys(m) { // want `unnecessary and inefficient call of maps.Keys`
	}

	for range maps.Values(m) { // want `unnecessary and inefficient call of maps.Values`
	}

	var x struct {
		Map map[int]int
	}
	x.Map = make(map[int]int)
	for x.Map[1] = range maps.Keys(m) { // want `unnecessary and inefficient call of maps.Keys`
	}

	for x.Map[2] = range maps.Values(m) { // want `unnecessary and inefficient call of maps.Values`
	}

	for k := range maps.Keys(m) { // want `unnecessary and inefficient call of maps.Keys`
		_ = k
	}

	for v := range maps.Values(m) { // want `unnecessary and inefficient call of maps.Values`
		_ = v
	}

	for range maps.Keys(x.Map) { // want `unnecessary and inefficient call of maps.Keys`
	}

	for /* comment */ k := range /* comment */ maps.Keys(/* comment */ m) { // want `unnecessary and inefficient call of maps.Keys`
		_ = k
	}
}

-- basic.go.golden --
package basic

import "maps"

func _() {
	m := make(map[int]int)

	for range m { // want `unnecessary and inefficient call of maps.Keys`
	}

	for range m { // want `unnecessary and inefficient call of maps.Values`
	}

	var x struct {
		Map map[int]int
	}
	x.Map = make(map[int]int)
	for x.Map[1] = range m { // want `unnecessary and inefficient call of maps.Keys`
	}

	for _, x.Map[2] = range m { // want `unnecessary and inefficient call of maps.Values`
	}

	for k := range m { // want `unnecessary and inefficient call of maps.Keys`
		_ = k
	}

	for _, v := range m { // want `unnecessary and inefficient call of maps.Values`
		_ = v
	}

	for range x.Map { // want `unnecessary and inefficient call of maps.Keys`
	}

	for /* comment */ k := range /* comment */ /* comment */ m { // want `unnecessary and inefficient call of maps.Keys`
		_ = k
	}
}

-- xmaps.go --
package basic

import "golang.org/x/exp/maps"

func _() {
	m := make(map[int]int)

	for range maps.Keys(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Keys`
	}

	for range maps.Values(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
	}

	for i := range maps.Values(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
		_ = i
	}

	var x struct {
		Map map[int]int
	}
	x.Map = make(map[int]int)
	for _, x.Map[1] = range maps.Keys(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Keys`
	}

	for _, x.Map[2] = range maps.Values(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
	}

	for _, k := range maps.Keys(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Keys`
		_ = k
	}

	for _, v := range maps.Values(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
		_ = v
	}

	for range maps.Keys(x.Map) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Keys`
	}

	for i, k := range maps.Keys(m) { // ok: this can't be straightforwardly rewritten
		_, _ = i, k
	}

	for _, _ = range maps.Values(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
	}
}

-- xmaps.go.golden --
package basic

import "golang.org/x/exp/maps"

func _() {
	m := make(map[int]int)

	for range m { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Keys`
	}

	for range m { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
	}

	for i := range len(m) { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
		_ = i
	}

	var x struct {
		Map map[int]int
	}
	x.Map = make(map[int]int)
	for x.Map[1] = range m { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Keys`
	}

	for _, x.Map[2] = range m { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
	}

	for k := range m { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Keys`
		_ = k
	}

	for _, v := range m { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
		_ = v
	}

	for range x.Map { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Keys`
	}

	for i, k := range maps.Keys(m) { // ok: this can't be straightforwardly rewritten
		_, _ = i, k
	}

	for _, _ = range m { // want `unnecessary and inefficient call of golang.org/x/exp/maps.Values`
	}
}

-- exp/go.mod --
module golang.org/x/exp

go 1.24

-- exp/maps/maps.go --
package maps

func Keys[M ~map[K]V, K comparable, V any](m M) []K {
	r := make([]K, 0, len(m))
	for k := range m {
		r = append(r, k)
	}
	return r
}

func Values[M ~map[K]V, K comparable, V any](m M) []V {
	r := make([]V, 0, len(m))
	for _, v := range m {
		r = append(r, v)
	}
	return r
}