break up group function

Group handled 3 separate pieces of logic, which have now been broken out for clarity and ease of use into:
Group - groups retaining existing middleware
GroupWithMore - groups retaining middleware and adding additional
GroupWithNone - groups but retains no middleware

README.md

@@ -1,5 +1,5 @@
 ## LARS
-<img align="right" src="https://raw.githubusercontent.com/go-playground/lars/master/examples/README/test.gif">![Project status](https://img.shields.io/badge/version-3.7.0-green.svg)
+<img align="right" src="https://raw.githubusercontent.com/go-playground/lars/master/examples/README/test.gif">![Project status](https://img.shields.io/badge/version-4.0.0-green.svg)
 [![Build Status](https://semaphoreci.com/api/v1/projects/4351aa2d-2f94-40be-a6ef-85c248490378/679708/badge.svg)](https://semaphoreci.com/joeybloggs/lars)
 [![Coverage Status](https://coveralls.io/repos/github/go-playground/lars/badge.svg?branch=master)](https://coveralls.io/github/go-playground/lars?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/go-playground/lars)](https://goreportcard.com/report/go-playground/lars)

group.go

@@ -10,7 +10,9 @@ import (
 // IRouteGroup interface for router group
 type IRouteGroup interface {
 	IRoutes
-	Group(prefix string, middleware ...Handler) IRouteGroup
+	GroupWithNone(prefix string) IRouteGroup
+	GroupWithMore(prefix string, middleware ...Handler) IRouteGroup
+	Group(prefix string) IRouteGroup
 }
 
 // IRoutes interface for routes
@@ -176,31 +178,34 @@ func (g *routeGroup) WebSocket(upgrader websocket.Upgrader, path string, h Handl
 	}, handler)
 }
 
-// Group creates a new sub router with prefix. It inherits all properties from
-// the parent. Passing middleware overrides parent middleware but still keeps
-// the root level middleware intact.
-func (g *routeGroup) Group(prefix string, middleware ...Handler) IRouteGroup {
-
-	rg := &routeGroup{
-		prefix: g.prefix + prefix,
-		lars:   g.lars,
-	}
-
-	if len(middleware) == 0 {
-		rg.middleware = make(HandlersChain, len(g.middleware))
-		copy(rg.middleware, g.middleware)
-
-		return rg
+// GroupWithNone creates a new sub router with specified prefix and no middleware attached.
+func (g *routeGroup) GroupWithNone(prefix string) IRouteGroup {
+	return &routeGroup{
+		prefix:     g.prefix + prefix,
+		lars:       g.lars,
+		middleware: make(HandlersChain, 0),
 	}
+}
 
-	if middleware[0] == nil {
-		rg.middleware = make(HandlersChain, 0)
-		return rg
+// GroupWithMore creates a new sub router with specified prefix, retains existing middleware and adds new middleware.
+func (g *routeGroup) GroupWithMore(prefix string, middleware ...Handler) IRouteGroup {
+	rg := &routeGroup{
+		prefix:     g.prefix + prefix,
+		lars:       g.lars,
+		middleware: make(HandlersChain, len(g.middleware)),
 	}
-
-	rg.middleware = make(HandlersChain, len(g.middleware))
 	copy(rg.middleware, g.middleware)
 	rg.Use(middleware...)
+	return rg
+}
 
+// Group creates a new sub router with specified prefix and retains existing middleware.
+func (g *routeGroup) Group(prefix string) IRouteGroup {
+	rg := &routeGroup{
+		prefix:     g.prefix + prefix,
+		lars:       g.lars,
+		middleware: make(HandlersChain, len(g.middleware)),
+	}
+	copy(rg.middleware, g.middleware)
 	return rg
 }

group_test.go

@@ -107,17 +107,17 @@ func TestGrouplogic(t *testing.T) {
 		c.Next()
 	})
 
-	a := l.Group("/a", aM)
+	a := l.GroupWithMore("/a", aM)
 	a.Get("/test", func(c Context) {
 		c.JSON(http.StatusOK, "a-ok")
 	})
 
-	b := a.Group("/b", bM)
+	b := a.GroupWithMore("/b", bM)
 	b.Get("/test", func(c Context) {
 		c.JSON(http.StatusOK, "b-ok")
 	})
 
-	c := b.Group("/c", cM)
+	c := b.GroupWithMore("/c", cM)
 	c.Get("/test", func(c Context) {
 		c.JSON(http.StatusOK, "c-ok")
 	})

lars_test.go

@@ -351,7 +351,7 @@ func TestUseAndGroup(t *testing.T) {
 		c.Next()
 	}
 
-	sh := l.Group("/superheros", logger2)
+	sh := l.GroupWithMore("/superheros", logger2)
 	sh.Get("/", fn)
 	sh.Get("/list/", fn)
 
@@ -381,7 +381,7 @@ func TestUseAndGroup(t *testing.T) {
 
 	log = ""
 
-	g2 := l.Group("/admins", nil)
+	g2 := l.GroupWithNone("/admins")
 	g2.Get("/", fn)
 	g2.Get("/list/", fn)