test(gin): Add comprehensive test coverage for ginS package (#4442)

* test(ginS): add comprehensive test coverage for ginS package

Improve test coverage for ginS package by adding 18 test functions covering HTTP methods, routing, middleware, static files, and templates.

* use http.Method* constants instead of raw strings in gins_test.go

* copyright updated in gins_test.go

---------

Co-authored-by: Bo-Yi Wu <appleboy.tw@gmail.com>

ginS/gins_test.go

@@ -0,0 +1,246 @@
+// Copyright 2025 Gin Core Team. All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package ginS
+
+import (
+	"html/template"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/assert"
+)
+
+func init() {
+	gin.SetMode(gin.TestMode)
+}
+
+func TestGET(t *testing.T) {
+	GET("/test", func(c *gin.Context) {
+		c.String(http.StatusOK, "test")
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/test", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "test", w.Body.String())
+}
+
+func TestPOST(t *testing.T) {
+	POST("/post", func(c *gin.Context) {
+		c.String(http.StatusCreated, "created")
+	})
+
+	req := httptest.NewRequest(http.MethodPost, "/post", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusCreated, w.Code)
+	assert.Equal(t, "created", w.Body.String())
+}
+
+func TestPUT(t *testing.T) {
+	PUT("/put", func(c *gin.Context) {
+		c.String(http.StatusOK, "updated")
+	})
+
+	req := httptest.NewRequest(http.MethodPut, "/put", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "updated", w.Body.String())
+}
+
+func TestDELETE(t *testing.T) {
+	DELETE("/delete", func(c *gin.Context) {
+		c.String(http.StatusOK, "deleted")
+	})
+
+	req := httptest.NewRequest(http.MethodDelete, "/delete", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "deleted", w.Body.String())
+}
+
+func TestPATCH(t *testing.T) {
+	PATCH("/patch", func(c *gin.Context) {
+		c.String(http.StatusOK, "patched")
+	})
+
+	req := httptest.NewRequest(http.MethodPatch, "/patch", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "patched", w.Body.String())
+}
+
+func TestOPTIONS(t *testing.T) {
+	OPTIONS("/options", func(c *gin.Context) {
+		c.String(http.StatusOK, "options")
+	})
+
+	req := httptest.NewRequest(http.MethodOptions, "/options", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "options", w.Body.String())
+}
+
+func TestHEAD(t *testing.T) {
+	HEAD("/head", func(c *gin.Context) {
+		c.String(http.StatusOK, "head")
+	})
+
+	req := httptest.NewRequest(http.MethodHead, "/head", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+}
+
+func TestAny(t *testing.T) {
+	Any("/any", func(c *gin.Context) {
+		c.String(http.StatusOK, "any")
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/any", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "any", w.Body.String())
+}
+
+func TestHandle(t *testing.T) {
+	Handle(http.MethodGet, "/handle", func(c *gin.Context) {
+		c.String(http.StatusOK, "handle")
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/handle", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "handle", w.Body.String())
+}
+
+func TestGroup(t *testing.T) {
+	group := Group("/group")
+	group.GET("/test", func(c *gin.Context) {
+		c.String(http.StatusOK, "group test")
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/group/test", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "group test", w.Body.String())
+}
+
+func TestUse(t *testing.T) {
+	var middlewareExecuted bool
+	Use(func(c *gin.Context) {
+		middlewareExecuted = true
+		c.Next()
+	})
+
+	GET("/middleware-test", func(c *gin.Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/middleware-test", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.True(t, middlewareExecuted)
+	assert.Equal(t, http.StatusOK, w.Code)
+}
+
+func TestNoRoute(t *testing.T) {
+	NoRoute(func(c *gin.Context) {
+		c.String(http.StatusNotFound, "custom 404")
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/nonexistent", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusNotFound, w.Code)
+	assert.Equal(t, "custom 404", w.Body.String())
+}
+
+func TestNoMethod(t *testing.T) {
+	NoMethod(func(c *gin.Context) {
+		c.String(http.StatusMethodNotAllowed, "method not allowed")
+	})
+
+	// This just verifies that NoMethod is callable
+	// Testing the actual behavior would require a separate engine instance
+	assert.NotNil(t, engine())
+}
+
+func TestRoutes(t *testing.T) {
+	GET("/routes-test", func(c *gin.Context) {})
+
+	routes := Routes()
+	assert.NotEmpty(t, routes)
+
+	found := false
+	for _, route := range routes {
+		if route.Path == "/routes-test" && route.Method == http.MethodGet {
+			found = true
+			break
+		}
+	}
+	assert.True(t, found)
+}
+
+func TestSetHTMLTemplate(t *testing.T) {
+	tmpl := template.Must(template.New("test").Parse("Hello {{.}}"))
+	SetHTMLTemplate(tmpl)
+
+	// Verify engine has template set
+	assert.NotNil(t, engine())
+}
+
+func TestStaticFile(t *testing.T) {
+	StaticFile("/static-file", "../testdata/test_file.txt")
+
+	req := httptest.NewRequest(http.MethodGet, "/static-file", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+}
+
+func TestStatic(t *testing.T) {
+	Static("/static-dir", "../testdata")
+
+	req := httptest.NewRequest(http.MethodGet, "/static-dir/test_file.txt", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+}
+
+func TestStaticFS(t *testing.T) {
+	fs := http.Dir("../testdata")
+	StaticFS("/static-fs", fs)
+
+	req := httptest.NewRequest(http.MethodGet, "/static-fs/test_file.txt", nil)
+	w := httptest.NewRecorder()
+	engine().ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+}