use enum

src/languages.ts

@@ -1,13 +1,19 @@
 // All the languages supported by CodeQL
-export const ALL_LANGUAGES = ['csharp', 'cpp', 'go', 'java', 'javascript', 'python'] as const;
-export type Language = (typeof ALL_LANGUAGES)[number];
+export enum Language {
+  csharp = 'csharp',
+  cpp = 'cpp',
+  go = 'go',
+  java = 'java',
+  javascript = 'javascript',
+  python = 'python',
+}
 
 // Additional names for languages
 const LANGUAGE_ALIASES: {[lang: string]: Language} = {
-  'c': 'cpp',
-  'c++': 'cpp',
-  'c#': 'csharp',
-  'typescript': 'javascript',
+  'c': Language.cpp,
+  'c++': Language.cpp,
+  'c#': Language.csharp,
+  'typescript': Language.javascript,
 };
 
 // Translate from user input or GitHub's API names for languages to CodeQL's names for languages
@@ -16,9 +22,8 @@ export function parseLanguage(language: string): Language | undefined {
   language = language.toLowerCase();
 
   // See if it's an exact match
-  const parsedLanguage = ALL_LANGUAGES.find(l => l === language);
-  if (parsedLanguage !== undefined) {
-    return parsedLanguage;
+  if (language in Language) {
+    return language as Language;
   }
 
   // Check language aliases