API.post returns null

[txnico]

Upon upgrading to "aws-amplify": "3.0.20" any call to API.post REST returns null.

To Reproduce
Running managed Expo app with Expo SDK 37
Any call to AWS lambda via API.post.

POST Response: null

Expected behavior
A response object to be returned once promise is complete.

Code Snippet

try {
    const apiName = 'userPreferences';
    const path = "/notifyPref?nType=" + nName + "&nValue=" + nValue;
    const myInit = {
        body: {},
        headers: {'Content-Type': 'application/json'}
    }

    var response = await API.post(apiName,path,myInit);
    console.log("POST Response:", response);
            
    if( !response.match(/Success/) ){
        toastType = 'danger';
        response = "Unable to set preference setting.\n" + response;
    }
            
} catch (err) {
    console.log("Error in userPreference update:",  err);
}

[manueliglesias]

Hi @txnico

Are you using your lambda as described here ?

UPDATE:
Which version were you on before when it was working correctly?

[txnico]

Hi @manueliglesias

I was at aws-amplify@1.1.19 with Expo SDK 35.

I used to have the API exports under: "aws_cloud_logic_custom" block and I've updated them to define them as API.endpoints with no change.

The lambda code is being executed correctly in AWS and the response as far as I can see in API-gateway logs have the expected response object.

Thanks!

[manueliglesias]

Can you share your redacted aws-exports.js or API.endpoints config?

[txnico]

Sure thing:

const awsmobile =  {
    "aws_project_region": "xxx",
    "aws_content_delivery_bucket": "xxx",
    "aws_content_delivery_bucket_region": "xxx",
    "aws_content_delivery_url": "xxx",
    "aws_cognito_identity_pool_id": "xxx",
    "aws_cognito_region": "xxx",
    "aws_user_pools_id": "xxx",
    "aws_user_pools_web_client_id": "xxx",
    /*
    "aws_cloud_logic_custom": [
        {
            "name": "deviceListRest",
            "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
            "region": "xxx"
        },
        {
            "name": "deviceControl",
            "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
            "region": "xxx"
        },
        {
            "name": "sensorData",
            "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
            "region": "xxx"
        },
        {
            "name": "Notifications",
            "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
            "region": "xxx"
        },
        {
            "name": "userPreferences",
            "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
            "region": "xxx"
        },
        {
            "name": "deviceSchedules",
            "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
            "region": "xxx
        }
    ], */
    //Get rid of: Unhandled promise rejection: Error: No credentials, applicationId or region
    //https://github.com/aws-amplify/amplify-js/issues/5918
    Analytics: {
        disabled: true
    }, 
    
    API: {
        endpoints: [
            {
                "name": "deviceListRest",
                "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
                "region": "xxx"
            },
            {
                "name": "deviceControl",
                "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
                "region": "xxx"
            },
            {
                "name": "sensorData",
                "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
                "region": "xxx"
            },
            {
                "name": "Notifications",
                "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
                "region": "xxx"
            },
            {
                "name": "userPreferences",
                "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
                "region": "xxx"
            },
            {
                "name": "deviceSchedules",
                "endpoint": "https://xxx.execute-api.xxx.amazonaws.com/Prod",
                "region": "xxx"
            }
        ]
    }
};

export default awsmobile;

[elorzafe]

@txnico can you share your package.json and how you are configuring Amplify?

[txnico]

@elorzafe - here's my package.json. Regarding the configuration, please see aws-exports I posted above.

{
"main": "node_modules/expo/AppEntry.js",
"scripts": {
"start": "expo start",
"android": "expo start --android",
"ios": "expo start --ios",
"eject": "expo eject"
},
"dependencies": {
"@expo/vector-icons": "10.1.0",
"@ptomasroos/react-native-multi-slider": "^2.2.2",
"@react-native-community/netinfo": "^5.9.4",
"aws-amplify": "3.0.10",
"aws-amplify-react-native": "4.1.1",
"expo": "^37.0.0",
"expo-constants": "~9.0.0",
"expo-localization": "~8.1.0",
"expo-permissions": "~8.1.0",
"moment": "^2.24.0",
"native-base": "^2.11.0",
"react": "16.9.0",
"react-native": "https://github.com/expo/react-native/archive/sdk-37.0.1.tar.gz",
"react-native-appearance": "~0.3.3",
"react-native-chart-kit": "4.3.0",
"react-native-circular-progress": "^1.1.0",
"react-native-gesture-handler": "~1.6.0",
"react-native-modal-datetime-picker": "^7.6.0",
"react-native-reanimated": "~1.7.0",
"react-native-screens": "^2.9.0",
"react-native-svg": "11.0.1",
"react-navigation": "^4.4.0",
"react-navigation-drawer": "^1.4.0",
"react-navigation-stack": "^1.7.3",
"react-navigation-tabs": "^1.2.0",
"victory-native": "^32.0.1"
},
"devDependencies": {
"babel-preset-expo": "^8.1.0"
},
"private": true
}

[elorzafe]

@txnico I mean are you doing something like this?

import { Amplify, API } from 'aws-amplify';
import awsconfig from './aws-exports';

Amplify.configure(awsconfig);

[txnico]

@elorzafe:

import Amplify from '@aws-amplify/core';
import Auth from '@aws-amplify/auth';
import { withAuthenticator } from 'aws-amplify-react-native';
import awsmobile from './aws-exports';

Amplify.configure(awsmobile);

[elorzafe]

@txnico where are you importing API?

[txnico]

@elorzafe - The imports above are in the main app entry-point whereas the API import happens in child components that execute api calls. I'm importing API as:

import { API } from 'aws-amplify';

[txnico]

Any update or suggestions?

[ashika01]

@txnico Have you tried to import Amplify from "aws-amplify" rather than core?If not could you give that a try, cleaning your node_modules and package lock files?

Something like this,

import Amplify, {API, Auth} from 'aws-amplify';
import { withAuthenticator } from 'aws-amplify-react-native';
import awsmobile from './aws-exports';

Amplify.configure(awsmobile);

[txnico]

Hi @ashika01 - same behavior unfortunately after clearing out node_modules, package lock files and updating imports.

[ashika01]

@txnico - I think this maybe related #5971

There is some explanation there. which region are you trying this from?

[txnico]

@ashika01 - Thanks for the suggestion. The API in question returns plain-text JSON responses and both #5971 and the referred CodeGenieApp/serverless-express#99 discuss mime types and compression.

[txnico]

I revisited this issue this week and found out that the issue was being caused by the lack of serialization in the body of the response object within my lambda function. It must have been a change in AWS API since previous API.post calls with the unedited lambda functions worked previously for months.

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