refactor: code

src/index.js

@@ -5,6 +5,7 @@ const { validate } = require("schema-utils");
 
 const {
   throttleAll,
+  memoize,
   terserMinify,
   uglifyJsMinify,
   swcMinify,
@@ -149,31 +150,6 @@ const { minify } = require("./minify");
  * @typedef {BasePluginOptions & { minimizer: { implementation: MinimizerImplementation<T>, options: MinimizerOptions<T> } }} InternalPluginOptions
  */
 
-/**
- * @template T
- * @param fn {(function(): any) | undefined}
- * @returns {function(): T}
- */
-const memoize = (fn) => {
-  let cache = false;
-  /** @type {T} */
-  let result;
-
-  return () => {
-    if (cache) {
-      return result;
-    }
-    result = /** @type {function(): any} */ (fn)();
-    cache = true;
-    // Allow to clean up memory for fn
-    // and all dependent resources
-    // eslint-disable-next-line no-undefined, no-param-reassign
-    fn = undefined;
-
-    return result;
-  };
-};
-
 const getTraceMapping = memoize(() =>
   // eslint-disable-next-line global-require
   require("@jridgewell/trace-mapping")

src/utils.js

@@ -755,8 +755,34 @@ esbuildMinify.getMinimizerVersion = () => {
   return packageJson && packageJson.version;
 };
 
+/**
+ * @template T
+ * @param fn {(function(): any) | undefined}
+ * @returns {function(): T}
+ */
+function memoize(fn) {
+  let cache = false;
+  /** @type {T} */
+  let result;
+
+  return () => {
+    if (cache) {
+      return result;
+    }
+    result = /** @type {function(): any} */ (fn)();
+    cache = true;
+    // Allow to clean up memory for fn
+    // and all dependent resources
+    // eslint-disable-next-line no-undefined, no-param-reassign
+    fn = undefined;
+
+    return result;
+  };
+}
+
 module.exports = {
   throttleAll,
+  memoize,
   terserMinify,
   uglifyJsMinify,
   swcMinify,

types/utils.d.ts

@@ -27,6 +27,12 @@ export type ExtractedComments = Array<string>;
  * @returns {Promise<T[]>} A promise that fulfills to an array of the results
  */
 export function throttleAll<T>(limit: number, tasks: Task<T>[]): Promise<T[]>;
+/**
+ * @template T
+ * @param fn {(function(): any) | undefined}
+ * @returns {function(): T}
+ */
+export function memoize<T>(fn: (() => any) | undefined): () => T;
 /**
  * @param {Input} input
  * @param {SourceMapInput | undefined} sourceMap