Improve getEnumNameFromValue and getEnumValueFromName performance

Author: drebrez

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Split up `CI` workflow into two separate workflows for the comment posting to work for PRs from forks.
+- Improved `getEnumNameFromValue` and `getEnumValueFromName` performance
 
 ## [1.2.1] - 2025-03-18
 

src/lib/enum.spec.ts

@@ -97,4 +97,14 @@ describe("enum tests", () => {
     const values = getEnumValues<TestEnum>(TestEnum);
     expect(values).toStrictEqual([TestEnum.A, TestEnum.B, TestEnum.C]);
   });
+
+  test("getEnumNames/getEnumValues with empty enum", () => {
+    enum TestEnum {}
+
+    const names = getEnumNames<TestEnum>(TestEnum);
+    expect(names).toStrictEqual([]);
+
+    const values = getEnumValues<TestEnum>(TestEnum);
+    expect(values).toStrictEqual([]);
+  });
 });

src/lib/enum.ts

@@ -13,7 +13,13 @@ export type StandardEnum<T> = {
  * @returns A string containing the name of the enum
  */
 export function getEnumNameFromValue<T>(enumVariable: StandardEnum<T>, enumValue: T): string {
-  return Object.keys(enumVariable)[Object.values(enumVariable).findIndex((x) => x === enumValue)];
+  let result = enumVariable[enumValue as keyof StandardEnum<T>] as string;
+
+  if (result === undefined && isEnumString(enumVariable)) {
+    result = Object.keys(enumVariable)[Object.values(enumVariable).indexOf(enumValue)];
+  }
+
+  return result;
 }
 
 /**
@@ -23,8 +29,7 @@ export function getEnumNameFromValue<T>(enumVariable: StandardEnum<T>, enumValue
  * @returns A string containing the value of the enum
  */
 export function getEnumValueFromName<T>(enumVariable: StandardEnum<T>, enumName: string): T {
-  const value = Object.values(enumVariable)[Object.keys(enumVariable).findIndex((x) => x === enumName)] as string;
-  return (isEnumString(enumVariable) ? value : Number.parseInt(value)) as T;
+  return enumVariable[enumName as keyof StandardEnum<T>] as T;
 }
 
 /**
@@ -59,7 +64,9 @@ export function getEnumValues<T>(enumVariable: StandardEnum<T>): T[] {
  * @returns A bool
  */
 function isEnumString<T>(enumVariable: StandardEnum<T>) {
-  const keys = Object.keys(enumVariable);
+  for (const key in enumVariable) {
+    return !/^\d+$/.test(key);
+  }
 
-  return keys.length > 0 && !/^\d+$/.test(keys.at(0) as string);
+  return false;
 }