Multi client oAuth redirect

authentication.js

const querystring = require('qs');

class MultiClientOauth extends OAuthStrategy {
  async getRedirect (data, params) {
    const redirectUrl = (params && params.redirect) || '/';
    const { redirect } = this.authentication.configuration.oauth;

    if (!redirect) {
      return null;
    }

    if(!redirect.some(url => redirectUrl.startsWith(url))) {
      throw new Error('Invalid redirect URL');
    }

    const authResult = data;
    const query = authResult.accessToken ? {
      access_token: authResult.accessToken
    } : {
      error: data.message || 'OAuth Authentication not successful'
    };

    return `${redirectUrl}#${querystring.stringify(query)}`;
  }
}

class GitHubStrategy extends MultiClientOauth {
  async getEntityData(profile) {
    const baseData = await super.getEntityData(profile);

    return {
      ...baseData,
      // You can also set the display name to profile.name
      name: profile.login,
      // The GitHub profile image
      avatar: profile.avatar_url,
      // The user email address (if available)
      email: profile.email
    };
  }
}