added singleton auth

Author: Code-Hex

src/auth.ts

@@ -1,11 +1,11 @@
-import { useEmulator } from "./emulator";
+import { Env, useEmulator } from "./emulator";
 import {
   createIdTokenVerifier,
   FirebaseIdToken,
   FirebaseTokenVerifier,
 } from "./token-verifier";
 
-export class Auth {
+export class BaseAuth {
   /** @internal */
   protected readonly idTokenVerifier: FirebaseTokenVerifier;
 
@@ -33,8 +33,8 @@ export class Auth {
    *   token's decoded claims if the ID token is valid; otherwise, a rejected
    *   promise.
    */
-  public verifyIdToken(idToken: string): Promise<FirebaseIdToken> {
-    const isEmulator = useEmulator();
+  public verifyIdToken(idToken: string, env?: Env): Promise<FirebaseIdToken> {
+    const isEmulator = useEmulator(env);
     return this.idTokenVerifier.verifyJWT(idToken, isEmulator);
   }
 }

src/emulator.ts

@@ -1,25 +1,15 @@
-declare global {
-  // Please set FIREBASE_AUTH_EMULATOR_HOST environment variable in your wrangler.toml.
-  // see: https://developers.cloudflare.com/workers/platform/environment-variables/#environment-variables-via-wrangler
-  //
-  // Example for wrangler.toml
-  // [vars]
-  // FIREBASE_AUTH_EMULATOR_HOST = "localhost:8080"
-  //
-  // # Override values for `--env production` usage
-  // [env.production.vars]
-  // FIREBASE_AUTH_EMULATOR_HOST = ""
-  const FIREBASE_AUTH_EMULATOR_HOST: string | undefined;
+export interface Env {
+  FIREBASE_AUTH_EMULATOR_HOST: string | undefined
 }
 
-function emulatorHost(): string | undefined {
-  return FIREBASE_AUTH_EMULATOR_HOST;
+export function emulatorHost(env?: Env): string | undefined {
+  return env?.FIREBASE_AUTH_EMULATOR_HOST;
 }
 
 /**
  * When true the SDK should communicate with the Auth Emulator for all API
  * calls and also produce unsigned tokens.
  */
-export const useEmulator = (): boolean => {
-  return !!emulatorHost();
+export const useEmulator = (env?: Env): boolean => {
+  return !!emulatorHost(env);
 };

src/index.ts

@@ -1,3 +1,35 @@
+import { BaseAuth } from "./auth"
+
+
 export {
-  Auth
-} from "./auth"
+  emulatorHost,
+  useEmulator
+} from "./emulator"
+export type { Env } from './emulator'
+
+export class Auth extends BaseAuth {
+  private static instance?: Auth;
+
+  private constructor(
+    projectId: string,
+    cacheKey: string,
+    cfPublicKeyCacheNamespace: KVNamespace
+  ) {
+    super(projectId, cacheKey, cfPublicKeyCacheNamespace)
+  }
+
+  static getOrInitialize(
+    projectId: string,
+    cacheKey: string,
+    cfPublicKeyCacheNamespace: KVNamespace
+  ): Auth {
+    if (!Auth.instance) {
+      Auth.instance = new Auth(
+        projectId,
+        cacheKey,
+        cfPublicKeyCacheNamespace,
+      )
+    }
+    return Auth.instance
+  }
+}