feat: improve memoize cache api and types

packages-node/providence-analytics/src/program/utils/memoize.js

@@ -1,6 +1,7 @@
-export const memoizeConfig = {
-  isCacheDisabled: false,
-};
+/**
+ * For testing purposes, it is possible to disable caching.
+ */
+let shouldCache = true;
 
 /**
  * @param {object|any[]|string} arg
@@ -13,37 +14,59 @@ function isObject(arg) {
  * @param {object|any[]|string} arg
  */
 function createCachableArg(arg) {
-  if (isObject(arg)) {
-    try {
-      return JSON.stringify(arg);
-    } catch {
-      return arg;
-    }
+  if (!isObject(arg)) return arg;
+  try {
+    return JSON.stringify(arg);
+  } catch {
+    return arg;
   }
-  return arg;
 }
 
 /**
+ * @template T
  * @type {<T>(functionToMemoize:T, opts?:{ storage?:object; serializeObjects?: boolean }) => T}
  */
 export function memoize(functionToMemoize, { storage = {}, serializeObjects = false } = {}) {
-  // @ts-ignore
+  // @ts-expect-erro
   // eslint-disable-next-line func-names
-  return function () {
-    // eslint-disable-next-line prefer-rest-params
-    const args = [...arguments];
-    const cachableArgs = !serializeObjects ? args : args.map(createCachableArg);
-    // Allow disabling of cache for testing purposes
-    // @ts-ignore
-    if (!memoizeConfig.isCacheDisabled && cachableArgs in storage) {
-      // @ts-ignore
-      return storage[cachableArgs];
+  return /** @type {* & T} */ (
+    function memoizedFn() {
+      // eslint-disable-next-line prefer-rest-params
+      const args = [...arguments];
+      const cachableArgs = !serializeObjects ? args : args.map(createCachableArg);
+      // Allow disabling of cache for testing purposes
+      // @ts-expect-error
+      if (shouldCache && cachableArgs in storage) {
+        // @ts-expect-error
+        return storage[cachableArgs];
+      }
+      // @ts-expect-error
+      const outcome = functionToMemoize.apply(this, args);
+      // @ts-expect-error
+      // eslint-disable-next-line no-param-reassign
+      storage[cachableArgs] = outcome;
+      return outcome;
     }
-    // @ts-ignore
-    const outcome = functionToMemoize.apply(this, args);
-    // @ts-ignore
-    // eslint-disable-next-line no-param-reassign
-    storage[cachableArgs] = outcome;
-    return outcome;
-  };
+  );
 }
+
+/**
+ * For testing purposes, it is possible to disable caching.
+ */
+memoize.disableCaching = () => {
+  shouldCache = false;
+};
+/**
+ * Once testing is done, it is possible to restore caching.
+ */
+memoize.restoreCaching = initialValue => {
+  shouldCache = initialValue || true;
+};
+
+Object.defineProperty(memoize, 'isCacheEnabled', {
+  // writable: false,
+  // enumerable: true,
+  get() {
+    return shouldCache;
+  },
+});