Fixes pipeline API

gin.go

@@ -71,6 +71,7 @@ func New() *Engine {
 		RouterGroup: RouterGroup{
 			Handlers: nil,
 			BasePath: "/",
+			root:     true,
 		},
 		RedirectTrailingSlash:  true,
 		RedirectFixedPath:      false,
@@ -133,10 +134,11 @@ func (engine *Engine) NoMethod(handlers ...HandlerFunc) {
 // Attachs a global middleware to the router. ie. the middlewares attached though Use() will be
 // included in the handlers chain for every single request. Even 404, 405, static files...
 // For example, this is the right place for a logger or error management middleware.
-func (engine *Engine) Use(middlewares ...HandlerFunc) {
+func (engine *Engine) Use(middlewares ...HandlerFunc) routesInterface {
 	engine.RouterGroup.Use(middlewares...)
 	engine.rebuild404Handlers()
 	engine.rebuild405Handlers()
+	return engine
 }
 
 func (engine *Engine) rebuild404Handlers() {

routergroup.go

@@ -11,17 +11,37 @@ import (
 	"strings"
 )
 
+type routesInterface interface {
+	Use(...HandlerFunc) routesInterface
+
+	Handle(string, string, ...HandlerFunc) routesInterface
+	Any(string, ...HandlerFunc) routesInterface
+	GET(string, ...HandlerFunc) routesInterface
+	POST(string, ...HandlerFunc) routesInterface
+	DELETE(string, ...HandlerFunc) routesInterface
+	PATCH(string, ...HandlerFunc) routesInterface
+	PUT(string, ...HandlerFunc) routesInterface
+	OPTIONS(string, ...HandlerFunc) routesInterface
+	HEAD(string, ...HandlerFunc) routesInterface
+
+	StaticFile(string, string) routesInterface
+	Static(string, string) routesInterface
+	StaticFS(string, http.FileSystem) routesInterface
+}
+
 // Used internally to configure router, a RouterGroup is associated with a prefix
 // and an array of handlers (middlewares)
 type RouterGroup struct {
 	Handlers HandlersChain
 	BasePath string
 	engine   *Engine
+	root     bool
 }
 
 // Adds middlewares to the group, see example code in github.
-func (group *RouterGroup) Use(middlewares ...HandlerFunc) {
+func (group *RouterGroup) Use(middlewares ...HandlerFunc) routesInterface {
 	group.Handlers = append(group.Handlers, middlewares...)
+	return group.returnObj()
 }
 
 // Creates a new router group. You should add all the routes that have common middlwares or the same path prefix.
@@ -44,64 +64,56 @@ func (group *RouterGroup) Group(relativePath string, handlers ...HandlerFunc) *R
 // This function is intended for bulk loading and to allow the usage of less
 // frequently used, non-standardized or custom methods (e.g. for internal
 // communication with a proxy).
-func (group *RouterGroup) handle(httpMethod, relativePath string, handlers HandlersChain) {
+func (group *RouterGroup) handle(httpMethod, relativePath string, handlers HandlersChain) routesInterface {
 	absolutePath := group.calculateAbsolutePath(relativePath)
 	handlers = group.combineHandlers(handlers)
 	group.engine.addRoute(httpMethod, absolutePath, handlers)
+	return group.returnObj()
 }
 
-func (group *RouterGroup) Handle(httpMethod, relativePath string, handlers ...HandlerFunc) *RouterGroup {
+func (group *RouterGroup) Handle(httpMethod, relativePath string, handlers ...HandlerFunc) routesInterface {
 	if matches, err := regexp.MatchString("^[A-Z]+$", httpMethod); !matches || err != nil {
 		panic("http method " + httpMethod + " is not valid")
 	}
-	group.handle(httpMethod, relativePath, handlers)
-	return group
-
+	return group.handle(httpMethod, relativePath, handlers)
 }
 
 // POST is a shortcut for router.Handle("POST", path, handle)
-func (group *RouterGroup) POST(relativePath string, handlers ...HandlerFunc) *RouterGroup {
-	group.handle("POST", relativePath, handlers)
-	return group
+func (group *RouterGroup) POST(relativePath string, handlers ...HandlerFunc) routesInterface {
+	return group.handle("POST", relativePath, handlers)
 }
 
 // GET is a shortcut for router.Handle("GET", path, handle)
-func (group *RouterGroup) GET(relativePath string, handlers ...HandlerFunc) *RouterGroup {
-	group.handle("GET", relativePath, handlers)
-	return group
+func (group *RouterGroup) GET(relativePath string, handlers ...HandlerFunc) routesInterface {
+	return group.handle("GET", relativePath, handlers)
 }
 
 // DELETE is a shortcut for router.Handle("DELETE", path, handle)
-func (group *RouterGroup) DELETE(relativePath string, handlers ...HandlerFunc) *RouterGroup {
-	group.handle("DELETE", relativePath, handlers)
-	return group
+func (group *RouterGroup) DELETE(relativePath string, handlers ...HandlerFunc) routesInterface {
+	return group.handle("DELETE", relativePath, handlers)
 }
 
 // PATCH is a shortcut for router.Handle("PATCH", path, handle)
-func (group *RouterGroup) PATCH(relativePath string, handlers ...HandlerFunc) *RouterGroup {
-	group.handle("PATCH", relativePath, handlers)
-	return group
+func (group *RouterGroup) PATCH(relativePath string, handlers ...HandlerFunc) routesInterface {
+	return group.handle("PATCH", relativePath, handlers)
 }
 
 // PUT is a shortcut for router.Handle("PUT", path, handle)
-func (group *RouterGroup) PUT(relativePath string, handlers ...HandlerFunc) *RouterGroup {
-	group.handle("PUT", relativePath, handlers)
-	return group
+func (group *RouterGroup) PUT(relativePath string, handlers ...HandlerFunc) routesInterface {
+	return group.handle("PUT", relativePath, handlers)
 }
 
 // OPTIONS is a shortcut for router.Handle("OPTIONS", path, handle)
-func (group *RouterGroup) OPTIONS(relativePath string, handlers ...HandlerFunc) *RouterGroup {
-	group.handle("OPTIONS", relativePath, handlers)
-	return group
+func (group *RouterGroup) OPTIONS(relativePath string, handlers ...HandlerFunc) routesInterface {
+	return group.handle("OPTIONS", relativePath, handlers)
 }
 
 // HEAD is a shortcut for router.Handle("HEAD", path, handle)
-func (group *RouterGroup) HEAD(relativePath string, handlers ...HandlerFunc) *RouterGroup {
-	group.handle("HEAD", relativePath, handlers)
-	return group
+func (group *RouterGroup) HEAD(relativePath string, handlers ...HandlerFunc) routesInterface {
+	return group.handle("HEAD", relativePath, handlers)
 }
 
-func (group *RouterGroup) Any(relativePath string, handlers ...HandlerFunc) *RouterGroup {
+func (group *RouterGroup) Any(relativePath string, handlers ...HandlerFunc) routesInterface {
 	// GET, POST, PUT, PATCH, HEAD, OPTIONS, DELETE, CONNECT, TRACE
 	group.handle("GET", relativePath, handlers)
 	group.handle("POST", relativePath, handlers)
@@ -112,10 +124,10 @@ func (group *RouterGroup) Any(relativePath string, handlers ...HandlerFunc) *Rou
 	group.handle("DELETE", relativePath, handlers)
 	group.handle("CONNECT", relativePath, handlers)
 	group.handle("TRACE", relativePath, handlers)
-	return group
+	return group.returnObj()
 }
 
-func (group *RouterGroup) StaticFile(relativePath, filepath string) *RouterGroup {
+func (group *RouterGroup) StaticFile(relativePath, filepath string) routesInterface {
 	if strings.Contains(relativePath, ":") || strings.Contains(relativePath, "*") {
 		panic("URL parameters can not be used when serving a static file")
 	}
@@ -124,7 +136,7 @@ func (group *RouterGroup) StaticFile(relativePath, filepath string) *RouterGroup
 	}
 	group.GET(relativePath, handler)
 	group.HEAD(relativePath, handler)
-	return group
+	return group.returnObj()
 }
 
 // Static serves files from the given file system root.
@@ -133,11 +145,11 @@ func (group *RouterGroup) StaticFile(relativePath, filepath string) *RouterGroup
 // To use the operating system's file system implementation,
 // use :
 //     router.Static("/static", "/var/www")
-func (group *RouterGroup) Static(relativePath, root string) *RouterGroup {
+func (group *RouterGroup) Static(relativePath, root string) routesInterface {
 	return group.StaticFS(relativePath, Dir(root, false))
 }
 
-func (group *RouterGroup) StaticFS(relativePath string, fs http.FileSystem) *RouterGroup {
+func (group *RouterGroup) StaticFS(relativePath string, fs http.FileSystem) routesInterface {
 	if strings.Contains(relativePath, ":") || strings.Contains(relativePath, "*") {
 		panic("URL parameters can not be used when serving a static folder")
 	}
@@ -147,7 +159,7 @@ func (group *RouterGroup) StaticFS(relativePath string, fs http.FileSystem) *Rou
 	// Register GET and HEAD handlers
 	group.GET(urlPattern, handler)
 	group.HEAD(urlPattern, handler)
-	return group
+	return group.returnObj()
 }
 
 func (group *RouterGroup) createStaticHandler(relativePath string, fs http.FileSystem) HandlerFunc {
@@ -176,3 +188,11 @@ func (group *RouterGroup) combineHandlers(handlers HandlersChain) HandlersChain
 func (group *RouterGroup) calculateAbsolutePath(relativePath string) string {
 	return joinPaths(group.BasePath, relativePath)
 }
+
+func (group *RouterGroup) returnObj() routesInterface {
+	if group.root {
+		return group.engine
+	} else {
+		return group
+	}
+}

routergroup_test.go

@@ -148,3 +148,30 @@ func TestRouterGroupBadMethod(t *testing.T) {
 		router.Handle("PATCh", "/")
 	})
 }
+
+func TestRouterGroupPipeline(t *testing.T) {
+	router := New()
+	testRoutesInterface(t, router)
+
+	v1 := router.Group("/v1")
+	testRoutesInterface(t, v1)
+}
+
+func testRoutesInterface(t *testing.T, r routesInterface) {
+	handler := func(c *Context) {}
+	assert.Equal(t, r, r.Use(handler))
+
+	assert.Equal(t, r, r.Handle("GET", "/handler", handler))
+	assert.Equal(t, r, r.Any("/any", handler))
+	assert.Equal(t, r, r.GET("/", handler))
+	assert.Equal(t, r, r.POST("/", handler))
+	assert.Equal(t, r, r.DELETE("/", handler))
+	assert.Equal(t, r, r.PATCH("/", handler))
+	assert.Equal(t, r, r.PUT("/", handler))
+	assert.Equal(t, r, r.OPTIONS("/", handler))
+	assert.Equal(t, r, r.HEAD("/", handler))
+
+	assert.Equal(t, r, r.StaticFile("/file", "."))
+	assert.Equal(t, r, r.Static("/static", "."))
+	assert.Equal(t, r, r.StaticFS("/static2", Dir(".", false)))
+}