Merge pull request #22 from IWANABETHATGUY/feature/optimization

perf(cache length of array, object): improve performance
planttheidea · Nov 2, 2019 · c30aae4 · c30aae4
2 parents dcd8d8f + 6a51495
commit c30aae4
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Showing 2 changed files with 8 additions and 9 deletions.
diff --git a/src/index.ts b/src/index.ts
@@ -81,9 +81,9 @@ function copy<T>(object: T, options?: FastCopy.Options): T {
     }
 
     let clone: any;
-
     // arrays
     if (isArray(object)) {
+      const objectLength = object.length;
       cache.add(object);
 
       // if strict, include non-standard properties
@@ -92,8 +92,7 @@ function copy<T>(object: T, options?: FastCopy.Options): T {
       }
 
       clone = new Constructor();
-
-      for (let index: number = 0; index < object.length; index++) {
+      for (let index: number = 0; index < objectLength; index++) {
         clone[index] = handleCopy(object[index], cache);
       }
 

diff --git a/src/utils.ts b/src/utils.ts
@@ -103,9 +103,9 @@ export const getObjectCloneLoose: FastCopy.ObjectCloner = (
 
   if (SUPPORTS.SYMBOL_PROPERTIES) {
     const symbols: symbol[] = getOwnPropertySymbols(object);
-
-    if (symbols.length) {
-      for (let index = 0, symbol; index < symbols.length; index++) {
+    const symbolsLength = symbols.length;
+    if (symbolsLength) {
+      for (let index = 0, symbol; index < symbolsLength; index++) {
         symbol = symbols[index];
 
         if (propertyIsEnumerable.call(object, symbol)) {
@@ -141,11 +141,11 @@ export const getObjectCloneStrict: FastCopy.ObjectCloner = (
   const properties: (string | symbol)[] = SUPPORTS.SYMBOL_PROPERTIES
     ? [].concat(getOwnPropertyNames(object), getOwnPropertySymbols(object))
     : getOwnPropertyNames(object);
-
-  if (properties.length) {
+  const propertiesLength = properties.length;
+  if (propertiesLength) {
     for (
       let index = 0, property, descriptor;
-      index < properties.length;
+      index < propertiesLength;
       index++
     ) {
       property = properties[index];