From 8f70ecb9117e537b558ac8e999c90d3035be4bfd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Flc=E3=82=9B?= <four_leaf_clover@foxmail.com>
Date: Wed, 19 Apr 2023 10:15:24 +0800
Subject: [PATCH] feat: Added `OptionFunc` and `With`

---
 gin.go      | 21 ++++++++++++++++++---
 gin_test.go | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/gin.go b/gin.go
index f95e5dda..d6f2fe03 100644
--- a/gin.go
+++ b/gin.go
@@ -47,6 +47,9 @@ var regRemoveRepeatedChar = regexp.MustCompile("/{2,}")
 // HandlerFunc defines the handler used by gin middleware as return value.
 type HandlerFunc func(*Context)
 
+// OptionFunc defines the function to change the default configuration
+type OptionFunc func(*Engine)
+
 // HandlersChain defines a HandlerFunc slice.
 type HandlersChain []HandlerFunc
 
@@ -180,7 +183,7 @@ var _ IRouter = (*Engine)(nil)
 // - ForwardedByClientIP:    true
 // - UseRawPath:             false
 // - UnescapePathValues:     true
-func New() *Engine {
+func New(opts ...OptionFunc) *Engine {
 	debugPrintWARNINGNew()
 	engine := &Engine{
 		RouterGroup: RouterGroup{
@@ -209,13 +212,16 @@ func New() *Engine {
 	engine.pool.New = func() any {
 		return engine.allocateContext(engine.maxParams)
 	}
+	for _, opt := range opts {
+		opt(engine)
+	}
 	return engine
 }
 
 // Default returns an Engine instance with the Logger and Recovery middleware already attached.
-func Default() *Engine {
+func Default(opts ...OptionFunc) *Engine {
 	debugPrintWARNINGDefault()
-	engine := New()
+	engine := New(opts...)
 	engine.Use(Logger(), Recovery())
 	return engine
 }
@@ -311,6 +317,15 @@ func (engine *Engine) Use(middleware ...HandlerFunc) IRoutes {
 	return engine
 }
 
+// With returns a new Engine instance with the provided options.
+func (engine *Engine) With(opts ...OptionFunc) *Engine {
+	for _, opt := range opts {
+		opt(engine)
+	}
+
+	return engine
+}
+
 func (engine *Engine) rebuild404Handlers() {
 	engine.allNoRoute = engine.combineHandlers(engine.noRoute)
 }
diff --git a/gin_test.go b/gin_test.go
index 8825ac7e..4550a7e5 100644
--- a/gin_test.go
+++ b/gin_test.go
@@ -696,3 +696,37 @@ func assertRoutePresent(t *testing.T, gotRoutes RoutesInfo, wantRoute RouteInfo)
 
 func handlerTest1(c *Context) {}
 func handlerTest2(c *Context) {}
+
+func TestNewOptionFunc(t *testing.T) {
+	var fc = func(e *Engine) {
+		e.GET("/test1", handlerTest1)
+		e.GET("/test2", handlerTest2)
+
+		e.Use(func(c *Context) {
+			c.Next()
+		})
+	}
+
+	r := New(fc)
+
+	routes := r.Routes()
+	assertRoutePresent(t, routes, RouteInfo{Path: "/test1", Method: "GET", Handler: "github.com/gin-gonic/gin.handlerTest1"})
+	assertRoutePresent(t, routes, RouteInfo{Path: "/test2", Method: "GET", Handler: "github.com/gin-gonic/gin.handlerTest2"})
+}
+
+func TestWithOptionFunc(t *testing.T) {
+	r := New()
+
+	r.With(func(e *Engine) {
+		e.GET("/test1", handlerTest1)
+		e.GET("/test2", handlerTest2)
+
+		e.Use(func(c *Context) {
+			c.Next()
+		})
+	})
+
+	routes := r.Routes()
+	assertRoutePresent(t, routes, RouteInfo{Path: "/test1", Method: "GET", Handler: "github.com/gin-gonic/gin.handlerTest1"})
+	assertRoutePresent(t, routes, RouteInfo{Path: "/test2", Method: "GET", Handler: "github.com/gin-gonic/gin.handlerTest2"})
+}