feat(iam-authenticator): expose refresh token with a getter - `getRef…

…reshToken()` (#122)

The `IamAuthenticator` class now makes the refresh token available to users through
a public method, `getRefreshToken`. This provides support to services that require
the refresh token as a part of their authentication scheme.

auth/authenticators/iam-authenticator.ts

@@ -118,4 +118,14 @@ export class IamAuthenticator extends TokenRequestBasedAuthenticator {
     // update properties in token manager
     this.tokenManager.setScope(scope);
   }
+
+  /**
+   * Return the most recently stored refresh token.
+   *
+   * @public
+   * @returns {string}
+   */
+  public getRefreshToken(): string {
+    return this.tokenManager.getRefreshToken();
+  }
 }

auth/token-managers/iam-token-manager.ts

@@ -52,6 +52,7 @@ interface Options extends JwtTokenManagerOptions {
  */
 export class IamTokenManager extends JwtTokenManager {
   protected requiredOptions = ['apikey'];
+  protected refreshToken: string;
   private apikey: string;
   private clientId: string;
   private clientSecret: string;
@@ -131,6 +132,33 @@ export class IamTokenManager extends JwtTokenManager {
     }
   }
 
+  /**
+   * Return the most recently stored refresh token.
+   *
+   * @public
+   * @returns {string}
+   */
+  public getRefreshToken(): string {
+    return this.refreshToken;
+  }
+
+  /**
+   * Extend this method from the parent class to extract the refresh token from
+   * the request and save it.
+   *
+   * @param tokenResponse - Response object from JWT service request
+   * @protected
+   * @returns {void}
+   */
+  protected saveTokenInfo(tokenResponse): void {
+    super.saveTokenInfo(tokenResponse);
+
+    const responseBody = tokenResponse.result || {};
+    if (responseBody.refresh_token) {
+      this.refreshToken = responseBody.refresh_token;
+    }
+  }
+
   /**
    * Request an IAM token using an API key.
    *

test/unit/iam-token-manager.test.js

@@ -21,10 +21,11 @@ RequestWrapper.mockImplementation(() => {
 
 const ACCESS_TOKEN = '9012';
 const CURRENT_ACCESS_TOKEN = '1234';
+const REFRESH_TOKEN = '3456';
 const IAM_RESPONSE = {
   result: {
     access_token: ACCESS_TOKEN,
-    refresh_token: '3456',
+    refresh_token: REFRESH_TOKEN,
     token_type: 'Bearer',
     expires_in: 3600,
     expiration: Math.floor(Date.now() / 1000) + 3600,
@@ -354,4 +355,17 @@ describe('iam_token_manager_v1', function() {
     expect(scope).toBeUndefined();
     done();
   });
+
+  it('should save and expose the refresh token', async () => {
+    const instance = new IamTokenManager({
+      apikey: 'abcd-1234',
+    });
+
+    mockSendRequest.mockImplementation(parameters => Promise.resolve(IAM_RESPONSE));
+
+    await instance.getToken();
+
+    expect(instance.refreshToken).toBe(REFRESH_TOKEN);
+    expect(instance.getRefreshToken()).toBe(REFRESH_TOKEN);
+  });
 });