fix(perf): avoid using klona for less options (#520)

package.json

@@ -44,9 +44,6 @@
     "less": "^3.5.0 || ^4.0.0",
     "webpack": "^5.0.0"
   },
-  "dependencies": {
-    "klona": "^2.0.6"
-  },
   "devDependencies": {
     "@babel/cli": "^7.21.5",
     "@babel/core": "^7.22.1",

src/utils.js

@@ -1,7 +1,5 @@
 import path from "path";
 
-import { klona } from "klona/full";
-
 /* eslint-disable class-methods-use-this */
 const trailingSlash = /[/\\]$/;
 
@@ -152,19 +150,18 @@ function createWebpackLessPlugin(loaderContext, implementation) {
 }
 
 /**
- * Get the less options from the loader context and normalizes its values
+ * Get the `less` options from the loader context and normalizes its values
  *
  * @param {object} loaderContext
  * @param {object} loaderOptions
  * @param {object} implementation
  * @returns {Object}
  */
 function getLessOptions(loaderContext, loaderOptions, implementation) {
-  const options = klona(
+  const options =
     typeof loaderOptions.lessOptions === "function"
       ? loaderOptions.lessOptions(loaderContext) || {}
-      : loaderOptions.lessOptions || {}
-  );
+      : loaderOptions.lessOptions || {};
 
   const lessOptions = {
     plugins: [],
@@ -174,18 +171,17 @@ function getLessOptions(loaderContext, loaderOptions, implementation) {
     ...options,
   };
 
+  const plugins = lessOptions.plugins.slice();
   const shouldUseWebpackImporter =
     typeof loaderOptions.webpackImporter === "boolean"
       ? loaderOptions.webpackImporter
       : true;
 
   if (shouldUseWebpackImporter) {
-    lessOptions.plugins.unshift(
-      createWebpackLessPlugin(loaderContext, implementation)
-    );
+    plugins.unshift(createWebpackLessPlugin(loaderContext, implementation));
   }
 
-  lessOptions.plugins.unshift({
+  plugins.unshift({
     install(lessProcessor, pluginManager) {
       // eslint-disable-next-line no-param-reassign
       pluginManager.webpackLoaderContext = loaderContext;
@@ -194,6 +190,8 @@ function getLessOptions(loaderContext, loaderOptions, implementation) {
     },
   });
 
+  lessOptions.plugins = plugins;
+
   return lessOptions;
 }
 

test/loader.test.js

@@ -70,15 +70,17 @@ describe("loader", () => {
         pluginInstalled = true;
       },
     };
-
+    const sourceMap = { outputSourceFiles: false };
+    const plugins = [testPlugin];
     const testId = "./basic.less";
     const compiler = await getCompiler(testId, {
-      lessOptions: {
-        plugins: [testPlugin],
-      },
+      sourceMap: true,
+      lessOptions: { plugins, sourceMap },
     });
     const stats = await compile(compiler);
 
+    expect(plugins).toHaveLength(1);
+    expect(sourceMap).toEqual({ outputSourceFiles: false });
     expect(pluginInstalled).toBe(true);
     expect(getWarnings(stats)).toMatchSnapshot("warnings");
     expect(getErrors(stats)).toMatchSnapshot("errors");