In this environment the sources for assign MUST be an object

Hi,

Trying to use the GraphQL API with a non AppSync set up and using a server that’s been created using API Gateway and a Lambda. I can call the API perfectly fine using an ID token I’ve either generated myself or from the Auth library within AWS Amplify, but whenever trying to call the API using Amplify I get the following:

TypeError: In this environment the sources for assign MUST be an object. This error is a performance optimization and not spec compliant.
    at Object.assign (blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:324)
    at APIClass.<anonymous> (blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:133915)
    at step (blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:133372)
    at Object.next (blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:133302)
    at fulfilled (blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:133254)
    at tryCallOne (blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:3732)
    at blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:3833
    at blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:3113
    at _callTimer (blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:3002)
    at _callImmediatesPass (blob:http://localhost:8081/7c7e07ee-d664-4756-b453-7471c07cb34d:3038)

I do have another issue open at the moment regarding HTTP method type, but for now I’ve updated the API to allow GET requests. The code in my React Native app looks like this:

import React, { Component } from 'react';
import Amplify, { API, Auth, graphqlOperation } from 'aws-amplify';

Amplify.Logger.LOG_LEVEL = 'DEBUG';

Amplify.configure({
  API: {
    graphql_endpoint: 'https://myurl.com/graphql',
    graphql_headers: async () => {
      const { idToken } = await Auth.currentSession();
      const Authorization = idToken.getJwtToken();

      console.log('ID token:', Authorization);

      return { Authorization };
    },
  },
  Auth: {
    identityPoolId: '***,
    region: '***',
    userPoolId: '***',
    userPoolWebClientId: '***',
  }
});

export default class App extends Component {
  async componentDidUpdate() {
    if (this.props.authState !== 'signedIn') {
      return null;
    }

    try {
      const query = graphqlOperation('valid_query');
      console.log(query);
      await API.graphql(query);
    } catch (error) {
      console.log(error);
    }
  }

  render() {
    if (this.props.authState !== 'signedIn') {
      return null;
    }
    // ...
  }
}

The code has been simplified a bit, but the only thing missing is the authenticator which works perfectly fine.

My dependencies are:

  "dependencies": {
    "aws-amplify": "^1.0.8",
    "aws-amplify-react-native": "^1.0.8",
    "native-base": "^2.8.0",
    "react": "16.4.1",
    "react-native": "0.56.0"
  },

Any idea why this might be happening?

Thanks, Gary

[demsey2]

I have the same issue, did you find a solution?

I also looked at the source of that error “In this environment the target of assign MUST be an object. This error is a performance optimization and not spec compliant.”. It comes from node_modules/react-native/Libraries/polyfills/Object.es6.js

and this is a comment for that polyfill

// WARNING: This is an optimized version that fails on hasOwnProperty checks
// and non objects. It's not spec-compliant. It's a perf optimization.
// This is only needed for iOS 8 and current Android JSC.

so it looks like aws-amplify uses Object.assign properly but for some reasons that polyfill is used. I am not sure how to skip that polyfill, I don’t need to support IOS8 and Android JSC.

I checked that polyfill and it looks like it has been fixed and now is spec-compliant https://github.com/facebook/react-native/commit/966bb63a80750757dc7a78d7d1f8960a2d8e25e0#diff-cb5173a6f8d88f7801f5127b94bfc330

so anyone with the problem should upgrade to react-native 0.57 and confirm if that helps to solve the issue, in my case I use Expo and the latest supported RN is 0.55.4 so I need to wait for the next Expo release

[lissau]

Great. Thank you for the feedback.