Add nonamedreturns linter (golangci#2701)

Author: firefart

.golangci.example.yml

@@ -790,6 +790,7 @@ linters-settings:
       - lostcancel
       - nilfunc
       - nilness
+      - nonamedreturns
       - printf
       - reflectvaluecompare
       - shadow
@@ -833,6 +834,7 @@ linters-settings:
       - lostcancel
       - nilfunc
       - nilness
+      - nonamedreturns
       - printf
       - reflectvaluecompare
       - shadow

go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/denis-tingaikin/go-header v0.4.3
 	github.com/esimonov/ifshort v1.0.4
 	github.com/fatih/color v1.13.0
+	github.com/firefart/nonamedreturns v1.0.0
 	github.com/fzipp/gocyclo v0.5.1
 	github.com/go-critic/go-critic v0.6.3
 	github.com/go-xmlfmt/xmlfmt v0.0.0-20191208150333-d5b6f63a941b

go.sum

@@ -37,7 +37,7 @@ func NewGodot() *goanalysis.Linter {
 
 		// Convert deprecated setting
 		// todo(butuzov): remove on v2 release
-		if cfg.CheckAll { // nolint:staticcheck
+		if cfg.CheckAll { // nolint:staticcheck // Keep for retro-compatibility.
 			settings.Scope = godot.AllScope
 		}
 

pkg/golinters/godot.go

@@ -0,0 +1,17 @@
+package golinters
+
+import (
+	"github.com/firefart/nonamedreturns/analyzer"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/pkg/golinters/goanalysis"
+)
+
+func NewNoNamedReturns() *goanalysis.Linter {
+	return goanalysis.NewLinter(
+		"nonamedreturns",
+		"Reports all named returns",
+		[]*analysis.Analyzer{analyzer.Analyzer},
+		nil,
+	).WithLoadMode(goanalysis.LoadModeSyntax)
+}

pkg/golinters/nonamedreturns.go

@@ -526,6 +526,11 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 			WithURL("https://github.com/sonatard/noctx").
 			WithNoopFallback(m.cfg),
 
+		linter.NewConfig(golinters.NewNoNamedReturns()).
+			WithSince("v1.46.0").
+			WithPresets(linter.PresetStyle).
+			WithURL("https://github.com/firefart/nonamedreturns"),
+
 		linter.NewConfig(golinters.NewParallelTest()).
 			WithSince("v1.33.0").
 			WithPresets(linter.PresetStyle, linter.PresetTest).

pkg/lint/lintersdb/manager.go

@@ -0,0 +1,94 @@
+//args: -Enonamedreturns
+package testdata
+
+import "fmt"
+
+type asdf struct {
+	test string
+}
+
+func noParams() {
+	return
+}
+
+var c = func() {
+	return
+}
+
+var d = func() error {
+	return nil
+}
+
+var e = func() (err error) { // ERROR `named return "err" with type "error" found`
+	err = nil
+	return
+}
+
+var (
+	f = func() {
+		return
+	}
+
+	g = func() error {
+		return nil
+	}
+
+	h = func() (err error) { // ERROR `named return "err" with type "error" found`
+		err = nil
+		return
+	}
+)
+
+// this should not match as the implementation does not need named parameters (see below)
+type funcDefintion func(arg1, arg2 interface{}) (num int, err error)
+
+func funcDefintionImpl(arg1, arg2 interface{}) (int, error) {
+	return 0, nil
+}
+
+func funcDefintionImpl2(arg1, arg2 interface{}) (num int, err error) { // ERROR `named return "num" with type "int" found`
+	return 0, nil
+}
+
+var funcVar = func() (msg string) { // ERROR `named return "msg" with type "string" found`
+	msg = "c"
+	return msg
+}
+
+func test() {
+	a := funcVar()
+	_ = a
+
+	var function funcDefintion
+	function = funcDefintionImpl
+	i, err := function("", "")
+	_ = i
+	_ = err
+	function = funcDefintionImpl2
+	i, err = function("", "")
+	_ = i
+	_ = err
+}
+
+func good(i string) string {
+	return i
+}
+
+func bad(i string, a, b int) (ret1 string, ret2 interface{}, ret3, ret4 int, ret5 asdf) { // ERROR `named return "ret1" with type "string" found`
+	x := "dummy"
+	return fmt.Sprintf("%s", x), nil, 1, 2, asdf{}
+}
+
+func bad2() (msg string, err error) { // ERROR `named return "msg" with type "string" found`
+	msg = ""
+	err = nil
+	return
+}
+
+func myLog(format string, args ...interface{}) {
+	return
+}
+
+type obj struct{}
+
+func (o *obj) func1() (err error) { return nil } // ERROR `named return "err" with type "error" found`