feat: add loopvar linter

.golangci.reference.yml

@@ -2297,6 +2297,7 @@ linters:
     - ireturn
     - lll
     - loggercheck
+    - loopvar
     - maintidx
     - makezero
     - maligned
@@ -2417,6 +2418,7 @@ linters:
     - ireturn
     - lll
     - loggercheck
+    - loopvar
     - maintidx
     - makezero
     - maligned

go.mod

@@ -59,6 +59,7 @@ require (
 	github.com/jingyugao/rowserrcheck v1.1.1
 	github.com/jirfag/go-printf-func-name v0.0.0-20200119135958-7558a9eaa5af
 	github.com/julz/importas v0.1.0
+	github.com/karamaru-alpha/loopvar v1.0.4
 	github.com/kisielk/errcheck v1.6.3
 	github.com/kkHAIKE/contextcheck v1.1.4
 	github.com/kulti/thelper v0.6.3

pkg/golinters/loopvar.go

@@ -0,0 +1,19 @@
+package golinters
+
+import (
+	"github.com/karamaru-alpha/loopvar"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
+)
+
+func NewLoopVar() *goanalysis.Linter {
+	a := loopvar.Analyzer
+
+	return goanalysis.NewLinter(
+		a.Name,
+		a.Doc,
+		[]*analysis.Analyzer{a},
+		nil,
+	).WithLoadMode(goanalysis.LoadModeTypesInfo)
+}

pkg/lint/lintersdb/manager.go

@@ -620,6 +620,12 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 			WithAlternativeNames("logrlint").
 			WithURL("https://github.com/timonwong/loggercheck"),
 
+		linter.NewConfig(golinters.NewLoopVar()).
+			WithSince("v1.56.0").
+			WithLoadForGoAnalysis().
+			WithPresets(linter.PresetStyle).
+			WithURL("https://github.com/karamaru-alpha/loopvar"),
+
 		linter.NewConfig(golinters.NewMaintIdx(maintIdxCfg)).
 			WithSince("v1.44.0").
 			WithPresets(linter.PresetComplexity).

test/testdata/loopvar.go

@@ -0,0 +1,38 @@
+//golangcitest:args -Eloopvar
+package testdata
+
+import (
+	"fmt"
+)
+
+func foo() {
+	slice := []int{1, 2, 3}
+	fns := make([]func(), 0, len(slice)*2)
+	for i, v := range slice {
+		i := i // want `The loop variable "i" should not be copied \(Go 1.22~ or Go 1.21 GOEXPERIMENT=loopvar\)`
+		fns = append(fns, func() {
+			fmt.Print(i)
+		})
+		_v := v // want `The loop variable "v" should not be copied \(Go 1.22~ or Go 1.21 GOEXPERIMENT=loopvar\)`
+		fns = append(fns, func() {
+			fmt.Print(_v)
+		})
+	}
+	for _, fn := range fns {
+		fn()
+	}
+}
+
+func bar() {
+	loopCount := 3
+	fns := make([]func(), 0, loopCount)
+	for i := 1; i <= loopCount; i++ {
+		i := i // want `The loop variable "i" should not be copied \(Go 1.22~ or Go 1.21 GOEXPERIMENT=loopvar\)`
+		fns = append(fns, func() {
+			fmt.Print(i)
+		})
+	}
+	for _, fn := range fns {
+		fn()
+	}
+}