fix(less): add plugins to less loader options type

src/loaders/less/index.ts

@@ -1,11 +1,11 @@
 import path from "path";
 
-import { Loader } from "../../types";
+import { Loader, LESSLoaderOptions } from "../../types";
 import loadModule from "../../utils/load-module";
 
 import importPlugin from "./import-plugin";
 
-const loader: Loader = {
+const loader: Loader<LESSLoaderOptions> = {
   name: "less",
   test: /\.less$/i,
   async process({ code, map }) {
@@ -14,9 +14,7 @@ const loader: Loader = {
 
     const res = await less.render(code, {
       ...this.options,
-      plugins: [importPlugin].concat(
-        Array.isArray(this.options.plugins) ? this.options.plugins : [],
-      ),
+      plugins: [importPlugin].concat(this.options.plugins || []),
       filename: this.id,
       sourceMap: this.sourceMap
         ? { outputSourceFiles: true, sourceMapBasepath: path.dirname(this.id) }

src/types.ts

@@ -2,6 +2,7 @@ import postcss from "postcss";
 import cssnano from "cssnano";
 import { PluginContext } from "rollup";
 import { Importer as SASSImporter } from "sass";
+import { Plugin as LESSPlugin } from "less";
 import { LocalByDefaultOptions } from "postcss-modules-local-by-default";
 import { ExtractImportsOptions } from "postcss-modules-extract-imports";
 import { ScopeOptions } from "postcss-modules-scope";
@@ -68,6 +69,15 @@ export type SASSLoaderOptions = {
   data?: string;
 };
 
+/** Options for Less Loader */
+export type LESSLoaderOptions = {
+  /**
+   * Array of Less plugins
+   * @default undefined
+   */
+  plugins?: LESSPlugin[];
+};
+
 /** Options for {@link Loaders} class */
 export interface LoadersOptions {
   /** @see {@link Options.use} */
@@ -291,7 +301,7 @@ export interface Options {
     | {
         sass?: SASSLoaderOptions & ObjectWithUnknownProps;
         stylus?: ObjectWithUnknownProps;
-        less?: ObjectWithUnknownProps;
+        less?: LESSLoaderOptions & ObjectWithUnknownProps;
       };
   /**
    * Array of custom loaders.