Refresh authToken when it expires

Access tokens have lifetimes that might end before the user wants to end
their authenticated session. Hence, we need to refresh the user access token
after an expiry detection.

Resolves: #175

Signed-off-by: fenn-cs <[email protected]>

src/classes/AuthenticationSession.ts

@@ -15,6 +15,8 @@ enum FusionAuthStatusCode {
 export class AuthenticationSession {
   public authToken = '';
 
+  public refreshToken = '';
+
   public readonly authContext;
 
   private readonly fusionAuthClient;
@@ -57,6 +59,7 @@ export class AuthenticationSession {
               username: this.authContext.username,
             });
             this.authToken = clientResponse.response.token;
+            this.refreshToken = clientResponse.response.refreshToken ?? '';
             this.authContext.accept();
             return;
           }
@@ -178,4 +181,18 @@ export class AuthenticationSession {
       this.authContext.reject();
     });
   }
+
+  private obtainNewAuthTokenUsingRefreshToken(): void {
+    this.fusionAuthClient.exchangeRefreshTokenForAccessToken(this.refreshToken, '', '', '', '')
+      .then((clientResponse) => {
+        this.authToken = clientResponse.response.access_token ?? '';
+      })
+      .catch((clientResponse: unknown) => {
+        const message = isPartialClientResponse(clientResponse)
+          ? clientResponse.exception.message
+          : '';
+        logger.warn(`Error obtaining refresh token : ${message}`);
+        this.authContext.reject();
+      });
+  }
 }