fix(utils): omit uses readonly prefix for key list

Author: mlaursen

packages/utils/src/omit.ts

@@ -1,9 +1,23 @@
-type R = Record<string, unknown>;
-
 /**
- * I really don't know how to typedef this. It just creates a new object that
- * has all the values copied over except for any keys that are defined in the
- * omitKeys param.
+ * Create a new object that does not contain the provided keys.
+ *
+ * @example
+ * Simple Examples
+ * ```ts
+ * const object = {
+ *   a: "",
+ *   b: 3,
+ *   c: false,
+ *   4: null,
+ * } as const;
+ *
+ * expect(omit(object, ["a"])).toEqual({
+ *   b: 3,
+ *   c: false,
+ *   4: null,
+ * });
+ * expect(omit(object, ["a", "c", "d"])).toEqual({ b: 3 });
+ * ```
  *
  * @internal
  * @param object - The object to remove keys from
@@ -12,17 +26,18 @@ type R = Record<string, unknown>;
  */
 export function omit<T extends object, K extends keyof T>(
   object: T,
-  omitKeys: K[] | string[]
+  omitKeys: readonly (K | string)[]
 ): Omit<T, K> {
   if (!omitKeys.length) {
     return object;
   }
 
-  return Object.keys(object).reduce((updated, key) => {
-    if (!(omitKeys as string[]).includes(key)) {
-      (updated as R)[key] = (object as R)[key];
+  const result: Record<string, unknown> = {};
+  for (const key in object) {
+    if (!omitKeys.includes(key as unknown as K)) {
+      result[key] = object[key];
     }
+  }
 
-    return updated;
-  }, {}) as Omit<T, K>;
+  return result as Omit<T, K>;
 }