google assistant account linking faliure - dialogflow-es

Question

I am trying to implement account linking in google actions. I've chosen Google and OAuth with Implicit linking type. In the Authorization URL I am validating the request and redirecting to google's oauth handler. Here is the sample code,
#Post('/google/actions/authorize')
public async authorizeGoogle(
#Req() request: Request,
#Res() response: Response,
#Body() authorizeRequest: DAuthorizeRequest,
) {
// tempToken is stored in cookie after login.
const tempToken = request.cookies['temp-token'];
if (!tempToken) {
throw new UnauthorizedException();
}
let token: DTemporaryToken;
try {
token = await this.jwtService.verifyAsync<DTemporaryToken>(tempToken);
} catch (err) {
throw new UnauthorizedException();
}
// validate request parameters are as it should be.
const valid = this.authService.validateGoogleOauthRequest(
token,
authorizeRequest,
);
if (!valid) {
throw new UnauthorizedException();
}
const user: User = await this.userService.findById(token.user_id);
const accessToken = await this.authService.generateAccessTokenForGoogle(
user,
);
const redirectUri = `${
authorizeRequest.redirect_uri
}?access_token=${accessToken}&error=${false}&token_type=bearer&state=${
authorizeRequest.state
}`;
response.redirect(redirectUri);
}
After the redirect I get this error,
Sorry, something went wrong, so I couldn't sign you in. But you can
try again later.
This is the dialogflow code
dialogFlowApp.intent(
'Default Welcome Intent',
async (conv: DialogflowConversation) => {
conv.ask(new SignIn('to access your data'));
},
);
dialogFlowApp.intent('sign_in', (conv, params, signIn) => {
console.log('SIGN IN', signIn)
conv.ask('how are you?');
})
And the console log for the signIn value is
SIGN IN { '#type':
'type.googleapis.com/google.actions.v2.SignInValue', status: 'ERROR' }
That's it, I can't figure out what is it that is going wrong. There is no descriptive enough error that should explain where this are going wrong.

Answer 1

it was a silly mistake on my part. The issue was in the redirect url, instead of sending the access_token and other parameters as url fragment, I was sending them as query parameter. So changing the access token generation to this fixed the issue.
const redirectUri = `${
authorizeRequest.redirect_uri
}#access_token=${accessToken}&error=${false}&token_type=bearer&state=${
authorizeRequest.state
}`;
Though, I still think the error reporting should be more comprehensive from google's end. It was a silly mistake which should have taken 10 seconds to fix instead of hours if the error was something more meaningful than Something went wrong