Add optional path parameters

Squashed commit of the following:

commit a0e345f2d1920b0be478d94ae56de21f446ec5bf
Author: Sergio Andres Virviescas Santana <[email protected]>
Date:   Sun Jul 14 18:26:23 2019 +0200

    Update README

commit f48f81403503ecda5057745414c27ba844a5a2b1
Author: Sergio Andres Virviescas Santana <[email protected]>
Date:   Sun Jul 14 18:14:06 2019 +0200

    Add test

commit 3a4aeb01482cbe79b5f95b09fca74ed194d309e7
Author: Sergio Andres Virviescas Santana <[email protected]>
Date:   Sun Jul 14 17:42:56 2019 +0200

    Fixes

commit 3ca5a4a5f158a716a9c99fc24d50d8e1688cd179
Author: Sergio Andres Virviescas Santana <[email protected]>
Date:   Sun Jul 14 11:31:43 2019 +0200

    Add optional path arguments

Author: Sergio Andres Virviescas Santana

README.md

@@ -126,6 +126,9 @@ Pattern: /user/:user
 
 **Note:** Since this router has only explicit matches, you can not register static routes and parameters for the same path segment. For example you can not register the patterns `/user/new` and `/user/:user` for the same request method at the same time. The routing of different request methods is independent from each other.
 
+#### Optional parameters
+If you need define an optional parameters, add `?` at the end of param name. `:name?`
+
 ### Catch-All parameters
 
 The second type are *catch-all* parameters and have the form `*name`.

examples/basic/basic.go

@@ -36,6 +36,7 @@ func main() {
 	r.GET("/", Index)
 	r.GET("/hello/:name", Hello)
 	r.GET("/multi/:name/:word", MultiParams)
+	r.GET("/optional/:name?/:word?", MultiParams)
 	r.GET("/ping", QueryArgs)
 
 	log.Fatal(fasthttp.ListenAndServe(":8080", r.Handler))

go.mod

@@ -1,7 +1,7 @@
 module github.com/fasthttp/router
 
 require (
-	github.com/savsgio/gotils v0.0.0-20190409142739-e36d23089e10
+	github.com/savsgio/gotils v0.0.0-20190714152828-365999d0a274
 	github.com/valyala/bytebufferpool v1.0.0
 	github.com/valyala/fasthttp v1.4.0
 )

go.sum

@@ -2,8 +2,8 @@ github.com/klauspost/compress v1.4.0 h1:8nsMz3tWa9SWWPL60G1V6CUsf4lLjWLTNEtibhe8
 github.com/klauspost/compress v1.4.0/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
 github.com/klauspost/cpuid v0.0.0-20180405133222-e7e905edc00e h1:+lIPJOWl+jSiJOc70QXJ07+2eg2Jy2EC7Mi11BWujeM=
 github.com/klauspost/cpuid v0.0.0-20180405133222-e7e905edc00e/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
-github.com/savsgio/gotils v0.0.0-20190409142739-e36d23089e10 h1:Rk4AHSMs6BX9Vb84H+SmYEA3X/VrtLV9qYSU/lc7xk4=
-github.com/savsgio/gotils v0.0.0-20190409142739-e36d23089e10/go.mod h1:w803/Fg1m0hrp1ZT9KNfQe4E4+WOMMFLcgzPvOcye10=
+github.com/savsgio/gotils v0.0.0-20190714152828-365999d0a274 h1:F52t1X2ziOrMcQMVHo8ZxwOrDTMAq6MrlKtL1Atu2wU=
+github.com/savsgio/gotils v0.0.0-20190714152828-365999d0a274/go.mod h1:w803/Fg1m0hrp1ZT9KNfQe4E4+WOMMFLcgzPvOcye10=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasthttp v1.4.0 h1:PuaTGZIw3mjYhhhbVbCQp8aciRZN9YdoB7MGX9Ko76A=

router.go

@@ -202,6 +202,36 @@ func (r *Router) DELETE(path string, handle fasthttp.RequestHandler) {
 	r.Handle("DELETE", path, handle)
 }
 
+// returns all possible paths when the original path has optional arguments
+func getOptionalPaths(path string) []string {
+	paths := make([]string, 0)
+
+	index := 0
+	newParam := false
+	for i := 0; i < len(path); i++ {
+		c := path[i]
+
+		if c == ':' {
+			index = i
+			newParam = true
+		} else if i > 0 && newParam && c == '?' {
+			p := strings.Replace(path[:index], "?", "", -1)
+			if !gotils.StringSliceInclude(paths, p) {
+				paths = append(paths, p)
+			}
+
+			p = strings.Replace(path[:i], "?", "", -1) + "/"
+			if !gotils.StringSliceInclude(paths, p) {
+				paths = append(paths, p)
+			}
+
+			newParam = false
+		}
+	}
+
+	return paths
+}
+
 // Handle registers a new request handle with the given path and method.
 //
 // For GET, POST, PUT, PATCH and DELETE requests the respective shortcut
@@ -227,7 +257,16 @@ func (r *Router) Handle(method, path string, handle fasthttp.RequestHandler) {
 		r.trees[method] = root
 	}
 
-	root.addRoute(path, handle)
+	optionalPaths := getOptionalPaths(path)
+
+	// if not has optional paths, adds the original
+	if len(optionalPaths) == 0 {
+		root.addRoute(path, handle)
+	} else {
+		for _, p := range optionalPaths {
+			root.addRoute(p, handle)
+		}
+	}
 }
 
 // ServeFiles serves files from the given file system root.

router_test.go

@@ -222,6 +222,33 @@ func TestRouterRoot(t *testing.T) {
 	}
 }
 
+func TestRouterOptionalPathArgs(t *testing.T) {
+	handler := func(ctx *fasthttp.RequestCtx) {
+		ctx.SetStatusCode(fasthttp.StatusOK)
+	}
+
+	expectedPaths := []string{
+		"/show/:name/",
+		"/show/:name/:surname/",
+		"/show/:name/:surname/at/",
+		"/show/:name/:surname/at/:address/",
+		"/show/:name/:surname/at/:address/:id/",
+		"/show/:name/:surname/at/:address/:id/:phone/",
+	}
+	r := New()
+	r.GET("/show/:name/:surname?/at/:address?/:id/:phone?", handler)
+
+	for _, path := range expectedPaths {
+		ctx := new(fasthttp.RequestCtx)
+
+		h, _ := r.Lookup("GET", path, ctx)
+
+		if h == nil {
+			t.Errorf("Expected optional path '%s' is not registered", path)
+		}
+	}
+}
+
 func TestRouterChaining(t *testing.T) {
 	r1 := New()
 	r2 := New()