1 files changed, 77 insertions, 0 deletions
diff --git a/vendor/github.com/mgechev/revive/rule/unused-receiver.go b/vendor/github.com/mgechev/revive/rule/unused-receiver.go
new file mode 100644
index 0000000000..43eaf83a49
--- /dev/null
+++ b/vendor/github.com/mgechev/revive/rule/unused-receiver.go
@@ -0,0 +1,77 @@
+package rule
+
+import (
+	"fmt"
+	"go/ast"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// UnusedReceiverRule lints unused params in functions.
+type UnusedReceiverRule struct{}
+
+// Apply applies the rule to given file.
+func (_ *UnusedReceiverRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+
+	onFailure := func(failure lint.Failure) {
+		failures = append(failures, failure)
+	}
+
+	w := lintUnusedReceiverRule{onFailure: onFailure}
+
+	ast.Walk(w, file.AST)
+
+	return failures
+}
+
+// Name returns the rule name.
+func (_ *UnusedReceiverRule) Name() string {
+	return "unused-receiver"
+}
+
+type lintUnusedReceiverRule struct {
+	onFailure func(lint.Failure)
+}
+
+func (w lintUnusedReceiverRule) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.FuncDecl:
+		if n.Recv == nil {
+			return nil // skip this func decl, not a method
+		}
+
+		rec := n.Recv.List[0] // safe to access only the first (unique) element of the list
+		if len(rec.Names) < 1 {
+			return nil // the receiver is anonymous: func (aType) Foo(...) ...
+		}
+
+		recID := rec.Names[0]
+		if recID.Name == "_" {
+			return nil // the receiver is already named _
+		}
+
+		// inspect the func body looking for references to the receiver id
+		fselect := func(n ast.Node) bool {
+			ident, isAnID := n.(*ast.Ident)
+
+			return isAnID && ident.Obj == recID.Obj
+		}
+		refs2recID := pick(n.Body, fselect, nil)
+
+		if len(refs2recID) > 0 {
+			return nil // the receiver is referenced in the func body
+		}
+
+		w.onFailure(lint.Failure{
+			Confidence: 1,
+			Node:       recID,
+			Category:   "bad practice",
+			Failure:    fmt.Sprintf("method receiver '%s' is not referenced in method's body, consider removing or renaming it as _", recID.Name),
+		})
+
+		return nil // full method body already inspected
+	}
+
+	return w
+}