new ADS rule: newerr

config.go

@@ -52,6 +52,7 @@ var allRules = append([]lint.Rule{
 	&rule.GetReturnRule{},
 	&rule.ModifiesParamRule{},
 	&rule.DeepExitRule{},
+	&rule.ADSNewErrRule{},
 }, defaultRules...)
 
 var allFormatters = []lint.Formatter{

fixtures/ads-newerror.go

@@ -0,0 +1,7 @@
+package fixtures
+
+import "errors"
+
+func foo(a, b, c, d int) {
+	errors.New("aaa")
+}

rule/ads-newerr.go

@@ -0,0 +1,97 @@
+package rule
+
+import (
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// ADSNewErrRule lints program exit at functions other than main or init.
+type ADSNewErrRule struct{}
+
+// Apply applies the rule to given file.
+func (r *ADSNewErrRule) Apply(file *lint.File, arguments lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	w := lintNewErr{onFailure, "errors", "New"}
+	ast.Walk(w, file.AST)
+	return failures
+}
+
+// Name returns the rule name.
+func (r *ADSNewErrRule) Name() string {
+	return "ads-newerr"
+}
+
+type lintNewErr struct {
+	onFailure  func(lint.Failure)
+	targetPkg  string
+	targetFunc string
+}
+
+func (w lintNewErr) Visit(node ast.Node) ast.Visitor {
+	ce, ok := node.(*ast.CallExpr)
+	if !ok {
+		return w
+	}
+
+	pkg, fn := getPkgFunc(ce)
+
+	if pkg == w.targetPkg && fn == w.targetFunc {
+		if pkg == "errors" && fn == "New" {
+			w.targetFunc = "MessageOption"
+			return w
+		}
+
+		s := searchErr{&w, ce}
+		for _, exp := range ce.Args {
+			ast.Walk(s, exp)
+		}
+
+		w.targetFunc = "New"
+	}
+
+	return w
+}
+
+type searchErr struct {
+	w  *lintNewErr
+	fc *ast.CallExpr
+}
+
+func (s searchErr) Visit(node ast.Node) ast.Visitor {
+
+	id, ok := node.(*ast.Ident)
+	if !ok {
+		return s
+	}
+	if id.Name == "err" {
+		s.w.onFailure(lint.Failure{
+			Confidence: 0.8,
+			Node:       s.fc,
+			Category:   "bad practice",
+			URL:        "#ads-newerr",
+			Failure:    "consider errors.Wrap instead of errors.New",
+		})
+
+	}
+
+	return s
+}
+
+func getPkgFunc(ce *ast.CallExpr) (string, string) {
+	fc, ok := ce.Fun.(*ast.SelectorExpr)
+	if !ok {
+		return "", ""
+	}
+	id, ok := fc.X.(*ast.Ident)
+	if !ok {
+		return "", ""
+	}
+
+	return id.Name, fc.Sel.Name
+
+}