[accept-language-parser] introduce generic

types/accept-language-parser/accept-language-parser-tests.ts

@@ -20,11 +20,17 @@ const l3: AcceptLanguageParser.Language = {
     quality: 0.9
 };
 
+type Lang = "en-US" | "ko-KR";
+const enUs: Lang = "en-US";
+const koKr: Lang = "ko-KR";
+
 const parsed1: AcceptLanguageParser.Language[] = AcceptLanguageParser.parse('');
 const pick1: string | null = AcceptLanguageParser.pick([''], '');
 const pick2: string | null = AcceptLanguageParser.pick([''], [l1, l2, l3]);
 const pick3: string | null = AcceptLanguageParser.pick([''], '', {});
 const pick4: string | null = AcceptLanguageParser.pick([''], '', { loose: true });
+const pick5: Lang | null = AcceptLanguageParser.pick<Lang>([enUs, koKr], [l1, l2, l3]);
+const pick6: Lang | null = AcceptLanguageParser.pick([enUs, koKr], [l1, l2, l3]);
 
 const pickOptions: AcceptLanguageParser.PickOptions = {
     loose: true

types/accept-language-parser/index.d.ts

@@ -1,17 +1,18 @@
 // Type definitions for accept-language-parser 1.5
 // Project: https://github.com/opentable/accept-language-parser
 // Definitions by: Niklas Wulf <https://github.com/kampfgnom>
+//                 Wooram Jun <https://github.com/chatoo2412>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.1
 
-// https://github.com/opentable/accept-language-parser/blob/v1.4.1/index.js
+// https://github.com/opentable/accept-language-parser/blob/v1.5.0/index.js
 
 export function parse(acceptLanguage: string): Language[];
-export function pick(
-    supportedLanguages: string[],
+export function pick<T extends string>(
+    supportedLanguages: T[],
     acceptLanguage: string | Language[],
     options?: PickOptions
-): string | null;
+): T | null;
 
 export interface Language {
     code: string;