add nosnakecase lint

Author: sivchari

go.mod

@@ -155,6 +155,7 @@ require (
 	github.com/quasilyte/gogrep v0.0.0-20220120141003-628d8b3623b5 // indirect
 	github.com/quasilyte/regex/syntax v0.0.0-20200407221936-30656e2c4a95 // indirect
 	github.com/quasilyte/stdinfo v0.0.0-20220114132959-f7386bf02567 // indirect
+	github.com/sivchari/nosnakecase v1.0.0
 	github.com/spf13/afero v1.8.2 // indirect
 	github.com/spf13/cast v1.4.1 // indirect
 	github.com/spf13/jwalterweatherman v1.1.0 // indirect

go.sum

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

pkg/golinters/nosnakecase.go

@@ -541,6 +541,11 @@ func (m Manager) GetAllSupportedLinterConfigs() []*linter.Config {
 			WithPresets(linter.PresetStyle).
 			WithURL("https://github.com/firefart/nonamedreturns"),
 
+		linter.NewConfig(golinters.NewNoSnakeCase()).
+			WithSince("v1.46.0").
+			WithPresets(linter.PresetStyle).
+			WithURL("https://github.com/sivchari/nosnakecase"),
+
 		linter.NewConfig(golinters.NewNoSprintfHostPort()).
 			WithSince("v1.46.0").
 			WithPresets(linter.PresetStyle).

pkg/lint/lintersdb/manager.go

@@ -0,0 +1,18 @@
+// args: -Enosnakecase
+package testdata
+
+func a_() { // ERROR "a_ is used under score. You should use mixedCap or MixedCap."
+}
+
+func b(a_a int) { // ERROR "a_a is used under score. You should use mixedCap or MixedCap."
+}
+
+func c() (c_c int) { // ERROR "c_c is used under score. You should use mixedCap or MixedCap."
+	c_c = 1    // ERROR "c_c is used under score. You should use mixedCap or MixedCap."
+	return c_c // ERROR "c_c is used under score. You should use mixedCap or MixedCap."
+}
+
+func d() {
+	var d_d int // ERROR "d_d is used under score. You should use mixedCap or MixedCap."
+	_ = d_d     // It's never detected, because `_` is meaningful in Go and `d_d` is already detected.
+}