feat: add SkipMethodNotAllowedMiddleware option

gin.go

@@ -122,6 +122,13 @@ type Engine struct {
 	// handler.
 	HandleMethodNotAllowed bool
 
+	// SkipMethodNotAllowedMiddleware if enabled, global middleware registered via Use()
+	// will not be executed for 405 Method Not Allowed responses. This allows
+	// NoMethod handlers to run without triggering middleware that may reject
+	// the request (e.g., authentication, checksum validation) before the 405
+	// response can be sent.
+	SkipMethodNotAllowedMiddleware bool
+
 	// ForwardedByClientIP if enabled, client IP will be parsed from the request's headers that
 	// match those stored at `(*gin.Engine).RemoteIPHeaders`. If no IP was
 	// fetched, it falls back to the IP obtained from
@@ -358,6 +365,10 @@ func (engine *Engine) rebuild404Handlers() {
 }
 
 func (engine *Engine) rebuild405Handlers() {
+	if engine.SkipMethodNotAllowedMiddleware {
+		engine.allNoMethod = engine.noMethod
+		return
+	}
 	engine.allNoMethod = engine.combineHandlers(engine.noMethod)
 }
 

gin_test.go

@@ -1156,3 +1156,62 @@ func TestUpdateRouteTreesCalledOnce(t *testing.T) {
 		assert.Equal(t, "ok", w.Body.String())
 	}
 }
+
+// Test the fix for https://github.com/gin-gonic/gin/issues/4189
+func TestSkipMethodNotAllowedMiddleware(t *testing.T) {
+	g := New()
+	g.HandleMethodNotAllowed = true
+	g.SkipMethodNotAllowedMiddleware = true
+
+	var middlewareCalled bool
+	middleware := func(c *Context) {
+		middlewareCalled = true
+		c.Next()
+	}
+	noMethodHandler := func(c *Context) {
+		c.String(http.StatusMethodNotAllowed, "method not allowed")
+	}
+
+	g.Use(middleware)
+	g.NoMethod(noMethodHandler)
+	g.POST("/test", func(c *Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/test", nil)
+	g.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusMethodNotAllowed, w.Code)
+	assert.Equal(t, "method not allowed", w.Body.String())
+	assert.False(t, middlewareCalled, "middleware should not be called when SkipMethodNotAllowedMiddleware is true")
+}
+
+func TestSkipMethodNotAllowedMiddlewareDisabled(t *testing.T) {
+	g := New()
+	g.HandleMethodNotAllowed = true
+	g.SkipMethodNotAllowedMiddleware = false
+
+	var middlewareCalled bool
+	middleware := func(c *Context) {
+		middlewareCalled = true
+		c.Next()
+	}
+	noMethodHandler := func(c *Context) {
+		c.String(http.StatusMethodNotAllowed, "method not allowed")
+	}
+
+	g.Use(middleware)
+	g.NoMethod(noMethodHandler)
+	g.POST("/test", func(c *Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/test", nil)
+	g.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusMethodNotAllowed, w.Code)
+	assert.Equal(t, "method not allowed", w.Body.String())
+	assert.True(t, middlewareCalled, "middleware should be called when SkipMethodNotAllowedMiddleware is false")
+}

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/mattn/go-isatty v0.0.20
 	github.com/modern-go/reflect2 v1.0.2
 	github.com/pelletier/go-toml/v2 v2.2.4
-	github.com/quic-go/quic-go v0.59.0
+	github.com/quic-go/quic-go v0.59.1
 	github.com/stretchr/testify v1.11.1
 	github.com/ugorji/go/codec v1.3.1
 	go.mongodb.org/mongo-driver/v2 v2.5.0

go.sum

@@ -52,8 +52,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/quic-go/qpack v0.6.0 h1:g7W+BMYynC1LbYLSqRt8PBg5Tgwxn214ZZR34VIOjz8=
 github.com/quic-go/qpack v0.6.0/go.mod h1:lUpLKChi8njB4ty2bFLX2x4gzDqXwUpaO1DP9qMDZII=
-github.com/quic-go/quic-go v0.59.0 h1:OLJkp1Mlm/aS7dpKgTc6cnpynnD2Xg7C1pwL6vy/SAw=
-github.com/quic-go/quic-go v0.59.0/go.mod h1:upnsH4Ju1YkqpLXC305eW3yDZ4NfnNbmQRCMWS58IKU=
+github.com/quic-go/quic-go v0.59.1 h1:0Gmua0HW1Tv7ANR7hUYwRyD0MG5OJfgvYSZasGZzBic=
+github.com/quic-go/quic-go v0.59.1/go.mod h1:upnsH4Ju1YkqpLXC305eW3yDZ4NfnNbmQRCMWS58IKU=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=