perf(trie-router): avoid calling spread operator for Object.create(null)

src/router/trie-router/node.ts

@@ -13,13 +13,15 @@ type HandlerParamsSet<T> = HandlerSet<T> & {
   params: Record<string, string>
 }
 
+const emptyParams = Object.create(null)
+
 export class Node<T> {
   #methods: Record<string, HandlerSet<T>>[]
 
   #children: Record<string, Node<T>>
   #patterns: Pattern[]
   #order: number = 0
-  #params: Record<string, string> = Object.create(null)
+  #params: Record<string, string> = emptyParams
 
   constructor(method?: string, handler?: T, children?: Record<string, Node<T>>) {
     this.#children = children || Object.create(null)
@@ -82,7 +84,7 @@ export class Node<T> {
     node: Node<T>,
     method: string,
     nodeParams: Record<string, string>,
-    params: Record<string, string>
+    params?: Record<string, string>
   ): HandlerParamsSet<T>[] {
     const handlerSets: HandlerParamsSet<T>[] = []
     for (let i = 0, len = node.#methods.length; i < len; i++) {
@@ -91,23 +93,24 @@ export class Node<T> {
       const processedSet: Record<number, boolean> = {}
       if (handlerSet !== undefined) {
         handlerSet.params = Object.create(null)
-        for (let i = 0, len = handlerSet.possibleKeys.length; i < len; i++) {
-          const key = handlerSet.possibleKeys[i]
-          const processed = processedSet[handlerSet.score]
-          handlerSet.params[key] =
-            params[key] && !processed ? params[key] : nodeParams[key] ?? params[key]
-          processedSet[handlerSet.score] = true
-        }
-
         handlerSets.push(handlerSet)
+        if (nodeParams !== emptyParams || (params && params !== emptyParams)) {
+          for (let i = 0, len = handlerSet.possibleKeys.length; i < len; i++) {
+            const key = handlerSet.possibleKeys[i]
+            const processed = processedSet[handlerSet.score]
+            handlerSet.params[key] =
+              params?.[key] && !processed ? params[key] : nodeParams[key] ?? params?.[key]
+            processedSet[handlerSet.score] = true
+          }
+        }
       }
     }
     return handlerSets
   }
 
   search(method: string, path: string): [[T, Params][]] {
     const handlerSets: HandlerParamsSet<T>[] = []
-    this.#params = Object.create(null)
+    this.#params = emptyParams
 
     // eslint-disable-next-line @typescript-eslint/no-this-alias
     const curNode: Node<T> = this
@@ -129,35 +132,25 @@ export class Node<T> {
             // '/hello/*' => match '/hello'
             if (nextNode.#children['*']) {
               handlerSets.push(
-                ...this.#getHandlerSets(
-                  nextNode.#children['*'],
-                  method,
-                  node.#params,
-                  Object.create(null)
-                )
+                ...this.#getHandlerSets(nextNode.#children['*'], method, node.#params)
               )
             }
-            handlerSets.push(
-              ...this.#getHandlerSets(nextNode, method, node.#params, Object.create(null))
-            )
+            handlerSets.push(...this.#getHandlerSets(nextNode, method, node.#params))
           } else {
             tempNodes.push(nextNode)
           }
         }
 
         for (let k = 0, len3 = node.#patterns.length; k < len3; k++) {
           const pattern = node.#patterns[k]
-
-          const params = { ...node.#params }
+          const params = node.#params === emptyParams ? {} : { ...node.#params }
 
           // Wildcard
           // '/hello/*/foo' => match /hello/bar/foo
           if (pattern === '*') {
             const astNode = node.#children['*']
             if (astNode) {
-              handlerSets.push(
-                ...this.#getHandlerSets(astNode, method, node.#params, Object.create(null))
-              )
+              handlerSets.push(...this.#getHandlerSets(astNode, method, node.#params))
               tempNodes.push(astNode)
             }
             continue