keycloak.js

 public getHeaderProvider(tokenUpdateTime: number) {
    const headerProvider = () => {
      const tokenUpdate = this.extract().updateToken(tokenUpdateTime) as any;
      // Keycloak doesn't use a proper promise. Instead it uses success and error.
      return new Promise((resolve, reject) => {
        tokenUpdate.success(() => {
          resolve({ "Authorization": "Bearer " + this.extract().token });
        }).error((error: any) => {
          // tslint:disable-next-line:no-console
          console.info("Cannot update keycloak token", error);
          reject(error);
        });
      });
    };
    return headerProvider;
  }