chore: Added the credentials API signatures and exposed admin.credential (#1035)

* chore: Added the credentials API signatures and exposed admin.credential

* fix: Updated ServiceAccountCredential constructor signature

Author: hiranya911

gulpfile.js

@@ -83,6 +83,7 @@ gulp.task('compile', function() {
 
   const configuration = [
     'lib/**/*.js',
+    'lib/credential/index.d.ts',
   ];
 
   workflow = workflow.pipe(filter(configuration));

src/credential/credential-interfaces.ts

@@ -14,17 +14,18 @@
  * limitations under the License.
  */
 
-// Use untyped import syntax for Node built-ins
 import fs = require('fs');
 import os = require('os');
 import path = require('path');
 
-import { GoogleOAuthAccessToken, Credential } from './credential-interfaces';
+import { Agent } from 'http';
+import { credential, GoogleOAuthAccessToken } from './index';
 import { AppErrorCodes, FirebaseAppError } from '../utils/error';
 import { HttpClient, HttpRequestConfig, HttpError, HttpResponse } from '../utils/api-request';
-import { Agent } from 'http';
 import * as util from '../utils/validator';
 
+import Credential = credential.Credential;
+
 const GOOGLE_TOKEN_AUDIENCE = 'https://accounts.google.com/o/oauth2/token';
 const GOOGLE_AUTH_TOKEN_HOST = 'accounts.google.com';
 const GOOGLE_AUTH_TOKEN_PATH = '/o/oauth2/token';

src/credential/credential-internal.ts

@@ -14,145 +14,31 @@
  * limitations under the License.
  */
 
-// Use untyped import syntax for Node built-ins
-import { Agent } from 'http';
 import {
-  ServiceAccountCredential, RefreshTokenCredential, getApplicationDefault 
+  ServiceAccountCredential, RefreshTokenCredential, getApplicationDefault
 } from './credential-internal';
-import { Credential } from './credential-interfaces';
+import { credential } from './index';
 
-let globalAppDefaultCred: Credential;
+let globalAppDefaultCred: credential.Credential;
 const globalCertCreds: { [key: string]: ServiceAccountCredential } = {};
 const globalRefreshTokenCreds: { [key: string]: RefreshTokenCredential } = {};
 
-/**
- * Returns a credential created from the
- * {@link
- *    https://developers.google.com/identity/protocols/application-default-credentials
- *    Google Application Default Credentials}
- * that grants admin access to Firebase services. This credential can be used
- * in the call to
- * {@link
- *   https://firebase.google.com/docs/reference/admin/node/admin#.initializeApp
- *  `admin.initializeApp()`}.
- *
- * Google Application Default Credentials are available on any Google
- * infrastructure, such as Google App Engine and Google Compute Engine.
- *
- * See
- * {@link
- *   https://firebase.google.com/docs/admin/setup#initialize_the_sdk
- *   Initialize the SDK}
- * for more details.
- *
- * @example
- * ```javascript
- * admin.initializeApp({
- *   credential: admin.credential.applicationDefault(),
- *   databaseURL: "https://<DATABASE_NAME>.firebaseio.com"
- * });
- * ```
- *
- * @param {!Object=} httpAgent Optional [HTTP Agent](https://nodejs.org/api/http.html#http_class_http_agent)
- *   to be used when retrieving access tokens from Google token servers.
- *
- * @return {!admin.credential.Credential} A credential authenticated via Google
- *   Application Default Credentials that can be used to initialize an app.
- */
-export function applicationDefault(httpAgent?: Agent): Credential {
+export const applicationDefault: typeof credential.applicationDefault = (httpAgent?) => {
   if (typeof globalAppDefaultCred === 'undefined') {
     globalAppDefaultCred = getApplicationDefault(httpAgent);
   }
   return globalAppDefaultCred;
 }
 
-/**
- * Returns a credential created from the provided service account that grants
- * admin access to Firebase services. This credential can be used in the call
- * to
- * {@link
- *   https://firebase.google.com/docs/reference/admin/node/admin#.initializeApp
- *   `admin.initializeApp()`}.
- *
- * See
- * {@link
- *   https://firebase.google.com/docs/admin/setup#initialize_the_sdk
- *   Initialize the SDK}
- * for more details.
- *
- * @example
- * ```javascript
- * // Providing a path to a service account key JSON file
- * var serviceAccount = require("path/to/serviceAccountKey.json");
- * admin.initializeApp({
- *   credential: admin.credential.cert(serviceAccount),
- *   databaseURL: "https://<DATABASE_NAME>.firebaseio.com"
- * });
- * ```
- *
- * @example
- * ```javascript
- * // Providing a service account object inline
- * admin.initializeApp({
- *   credential: admin.credential.cert({
- *     projectId: "<PROJECT_ID>",
- *     clientEmail: "foo@<PROJECT_ID>.iam.gserviceaccount.com",
- *     privateKey: "-----BEGIN PRIVATE KEY-----<KEY>-----END PRIVATE KEY-----\n"
- *   }),
- *   databaseURL: "https://<DATABASE_NAME>.firebaseio.com"
- * });
- * ```
- *
- * @param serviceAccountPathOrObject The path to a service
- *   account key JSON file or an object representing a service account key.
- * @param httpAgent Optional [HTTP Agent](https://nodejs.org/api/http.html#http_class_http_agent)
- *   to be used when retrieving access tokens from Google token servers.
- *
- * @return A credential authenticated via the
- *   provided service account that can be used to initialize an app.
- */
-export function cert(serviceAccountPathOrObject: string | object, httpAgent?: Agent): Credential {
+export const cert: typeof credential.cert = (serviceAccountPathOrObject, httpAgent?) => {
   const stringifiedServiceAccount = JSON.stringify(serviceAccountPathOrObject);
   if (!(stringifiedServiceAccount in globalCertCreds)) {
     globalCertCreds[stringifiedServiceAccount] = new ServiceAccountCredential(serviceAccountPathOrObject, httpAgent);
   }
   return globalCertCreds[stringifiedServiceAccount];
 }
 
-/**
- * Returns a credential created from the provided refresh token that grants
- * admin access to Firebase services. This credential can be used in the call
- * to
- * {@link
- *   https://firebase.google.com/docs/reference/admin/node/admin#.initializeApp
- *   `admin.initializeApp()`}.
- *
- * See
- * {@link
- *   https://firebase.google.com/docs/admin/setup#initialize_the_sdk
- *   Initialize the SDK}
- * for more details.
- *
- * @example
- * ```javascript
- * // Providing a path to a refresh token JSON file
- * var refreshToken = require("path/to/refreshToken.json");
- * admin.initializeApp({
- *   credential: admin.credential.refreshToken(refreshToken),
- *   databaseURL: "https://<DATABASE_NAME>.firebaseio.com"
- * });
- * ```
- *
- * @param refreshTokenPathOrObject The path to a Google
- *   OAuth2 refresh token JSON file or an object representing a Google OAuth2
- *   refresh token.
- * @param httpAgent Optional [HTTP Agent](https://nodejs.org/api/http.html#http_class_http_agent)
- *   to be used when retrieving access tokens from Google token servers.
- *
- * @return A credential authenticated via the
- *   provided service account that can be used to initialize an app.
- */
-export function refreshToken(refreshTokenPathOrObject: string | object, httpAgent?: Agent): Credential {
+export const refreshToken: typeof credential.refreshToken = (refreshTokenPathOrObject, httpAgent) => {
   const stringifiedRefreshToken = JSON.stringify(refreshTokenPathOrObject);
   if (!(stringifiedRefreshToken in globalRefreshTokenCreds)) {
     globalRefreshTokenCreds[stringifiedRefreshToken] = new RefreshTokenCredential(