From 05c4801f9be1c3727e640c5c314cdf0694fce956 Mon Sep 17 00:00:00 2001
From: Shoichi Kaji <skaji@cpan.org>
Date: Thu, 15 Aug 2024 20:29:11 +0900
Subject: [PATCH] check param, result, type param of function in
 redefines-builtin-id rule (#1023)

* check param, result, type param of function in redefines-builtin-id rule

* combine the if statements

* tiny refactoring to make it more Go idiomatic

---------

Co-authored-by: chavacava <salvadorcavadini+github@gmail.com>
---
 rule/redefines-builtin-id.go     | 25 +++++++++++++++++++++++++
 testdata/redefines-builtin-id.go | 11 +++++++++++
 2 files changed, 36 insertions(+)

diff --git a/rule/redefines-builtin-id.go b/rule/redefines-builtin-id.go
index f367ea8..8aaaf03 100644
--- a/rule/redefines-builtin-id.go
+++ b/rule/redefines-builtin-id.go
@@ -145,6 +145,31 @@ func (w *lintRedefinesBuiltinID) Visit(node ast.Node) ast.Visitor {
 		if ok, bt := w.isBuiltIn(id); ok {
 			w.addFailure(n, fmt.Sprintf("redefinition of the built-in %s %s", bt, id))
 		}
+	case *ast.FuncType:
+		var fields []*ast.Field
+		if n.TypeParams != nil {
+			fields = append(fields, n.TypeParams.List...)
+		}
+		if n.Params != nil {
+			fields = append(fields, n.Params.List...)
+		}
+		if n.Results != nil {
+			fields = append(fields, n.Results.List...)
+		}
+		for _, field := range fields {
+			for _, name := range field.Names {
+				obj := name.Obj
+				isTypeOrName := obj != nil && (obj.Kind == ast.Var || obj.Kind == ast.Typ)
+				if !isTypeOrName {
+					continue
+				}
+				
+				id := obj.Name
+				if ok, bt := w.isBuiltIn(id); ok {
+					w.addFailure(name, fmt.Sprintf("redefinition of the built-in %s %s", bt, id))
+				}
+			}
+		}
 	case *ast.AssignStmt:
 		for _, e := range n.Lhs {
 			id, ok := e.(*ast.Ident)
diff --git a/testdata/redefines-builtin-id.go b/testdata/redefines-builtin-id.go
index e5f7c16..2426b10 100644
--- a/testdata/redefines-builtin-id.go
+++ b/testdata/redefines-builtin-id.go
@@ -41,3 +41,14 @@ func foo() {
 	_ = max
 	_ = min
 }
+
+func foo1(new int) { // MATCH /redefinition of the built-in function new/
+	_ = new
+}
+
+func foo2() (new int) { // MATCH /redefinition of the built-in function new/
+	return
+}
+
+func foo3[new any]() { // MATCH /redefinition of the built-in function new/
+}