Throw an explicit exception if encountering id token parse error

Author: dmitrizagidulin

src/AuthenticationResponse.js

@@ -360,13 +360,20 @@ class AuthenticationResponse {
    * @param response.params {object}
    * @param response.params.id_token {string} IDToken encoded as a JWT
    *
-   * @returns {Promise<AuthenticationResponse>} Chainable
+   * @returns {AuthenticationResponse} Chainable
    */
   static decodeIDToken (response) {
     let jwt = response.params.id_token
 
     if (jwt) {
-      response.decoded = IDToken.decode(jwt)
+      try {
+        response.decoded = IDToken.decode(jwt)
+      } catch (decodeError) {
+        const error = new HttpError(400, 'Error decoding ID Token')
+        error.cause = decodeError
+        error.info = { id_token: jwt }
+        throw error
+      }
     }
 
     return response

test/AuthenticationResponseSpec.js

@@ -494,6 +494,13 @@ describe('AuthenticationResponse', () => {
         .to.be.undefined()
     })
 
+    it('should throw an error on invalid id_token', () => {
+      response.params.id_token = 'inva1id'
+      expect(() => {
+        AuthenticationResponse.decodeIDToken(response)
+      }).to.throw('Error decoding ID Token')
+    })
+
     it('should return its argument', () => {
       AuthenticationResponse.decodeIDToken(response).should.equal(response)
     })