lib/path: add method Set to Route

The Set method set or replace the key's value in path with parameter val.
If the key exist it will return true; otherwise it will return false.

This changes remove unnecessary field key in routeNode and optimize
the String method using [strings.Builder].

4 files changed, 77 insertions, 13 deletions

diff --git a/lib/path/route.go b/lib/path/route.go
index 7548d056..1cf9d419 100644
--- a/lib/path/route.go
+++ b/lib/path/route.go
@@ -53,12 +53,12 @@ func NewRoute(rpath string) (rute *Route, err error) {
 		var node = &routeNode{}
 
 		if subpath[0] == ':' {
-			node.key = strings.TrimSpace(subpath[1:])
-			if len(node.key) == 0 {
+			node.name = strings.TrimSpace(subpath[1:])
+			if len(node.name) == 0 {
 				return nil, ErrPathKeyEmpty
 			}
 
-			if rute.isKeyExist(node.key) {
+			if rute.isKeyExist(node.name) {
 				return nil, ErrPathKeyDuplicate
 			}
 
@@ -87,7 +87,7 @@ func (rute *Route) isKeyExist(key string) bool {
 		if !node.isKey {
 			continue
 		}
-		if node.key == key {
+		if node.name == key {
 			return true
 		}
 	}
@@ -121,7 +121,7 @@ func (rute *Route) Parse(rpath string) (vals map[string]string, ok bool) {
 
 	for x, node = range rute.nodes {
 		if node.isKey {
-			vals[node.key] = paths[x]
+			vals[node.name] = paths[x]
 		} else if paths[x] != node.name {
 			return nil, false
 		}
@@ -130,17 +130,49 @@ func (rute *Route) Parse(rpath string) (vals map[string]string, ok bool) {
 	return vals, true
 }
 
+// Set or replace the key's value in path with parameter val.
+// If the key exist it will return true; otherwise it will return false.
+func (rute *Route) Set(key, val string) bool {
+	key = strings.TrimSpace(key)
+	if len(key) == 0 {
+		return false
+	}
+	key = strings.ToLower(key)
+
+	var node *routeNode
+	for _, node = range rute.nodes {
+		if !node.isKey {
+			continue
+		}
+		if node.name == key {
+			node.val = val
+			return true
+		}
+	}
+	return false
+}
+
 // String generate a clean path without any white spaces and single "/"
 // between sub-path.
+// If the key has been [Route.Set], the sub-path will be replaced with its
+// value, otherwise it will returned as ":<key>".
 func (rute *Route) String() (path string) {
-	var node *routeNode
+	var (
+		node *routeNode
+		pb   strings.Builder
+	)
 	for _, node = range rute.nodes {
-		path += `/`
+		pb.WriteByte('/')
 		if node.isKey {
-			path += `:` + node.key
+			if len(node.val) == 0 {
+				pb.WriteByte(':')
+				pb.WriteString(node.name)
+			} else {
+				pb.WriteString(node.val)
+			}
 		} else {
-			path += node.name
+			pb.WriteString(node.name)
 		}
 	}
-	return path
+	return pb.String()
 }
diff --git a/lib/path/route_example_test.go b/lib/path/route_example_test.go
new file mode 100644
index 00000000..d97603c1
--- /dev/null
+++ b/lib/path/route_example_test.go
@@ -0,0 +1,32 @@
+// Copyright 2024, Shulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package path_test
+
+import (
+	"fmt"
+	"log"
+
+	libpath "github.com/shuLhan/share/lib/path"
+)
+
+func ExampleRoute_Set() {
+	var (
+		rute *libpath.Route
+		err  error
+	)
+	rute, err = libpath.NewRoute(`/:user/:repo`)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	rute.Set(`user`, `shuLhan`)
+	fmt.Println(rute)
+
+	rute.Set(`repo`, `share`)
+	fmt.Println(rute)
+	// Output:
+	// /shuLhan/:repo
+	// /shuLhan/share
+}
diff --git a/lib/path/route_node.go b/lib/path/route_node.go
index dd1b06b0..b89ab24e 100644
--- a/lib/path/route_node.go
+++ b/lib/path/route_node.go
@@ -10,7 +10,7 @@ package path
 // A sub-path that start with colon ":" is a key; otherwise its normal
 // sub-path.
 type routeNode struct {
-	key   string
 	name  string
+	val   string
 	isKey bool
 }
diff --git a/lib/path/route_test.go b/lib/path/route_test.go
index c0c7ba01..bd3bcbbb 100644
--- a/lib/path/route_test.go
+++ b/lib/path/route_test.go
@@ -46,10 +46,10 @@ func TestNewRoute(t *testing.T) {
 		exp: &Route{
 			path: `/:user/:repo`,
 			nodes: []*routeNode{{
-				key:   `user`,
+				name:  `user`,
 				isKey: true,
 			}, {
-				key:   `repo`,
+				name:  `repo`,
 				isKey: true,
 			}},
 			nkey: 2,