awsmobile pull/push fails with cryptic error

[dan1elhughes]

> awsmobile pull

retrieving the latest backend awsmobile project information
awsmobile project's details logged at:
    awsmobilejs/#current-backend-info/backend-details.json
awsmobile project's specifications logged at:
    awsmobilejs/#current-backend-info/mobile-hub-project.yml
awsmobile project's access information logged at: 
    awsmobilejs/#current-backend-info/aws-exports.js
awsmobile project's access information copied to: 
    src/aws-exports.js
contents in #current-backend-info/ is synchronized with the latest in the aws cloud
? sync corresponding contents in backend/ with #current-backend-info/ Yes
(node:8281) UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'lastPushSuccessful' of undefined
    at Object.syncToDevBackend (/home/ddhughes/.npm-global/lib/node_modules/awsmobile-cli/lib/backend-operations/ops-appsync.js:139:21)
    at /home/ddhughes/.npm-global/lib/node_modules/awsmobile-cli/lib/backend-operations/backend-info-manager.js:180:24
    at Array.forEach (<anonymous>)
    at syncAllToDev (/home/ddhughes/.npm-global/lib/node_modules/awsmobile-cli/lib/backend-operations/backend-info-manager.js:178:25)
    at /home/ddhughes/.npm-global/lib/node_modules/awsmobile-cli/lib/backend-operations/backend-info-manager.js:161:21
(node:8281) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:8281) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

I'm not entirely sure what this error means or how to go about resolving it, I get the same error when I try to push or deploy

[dan1elhughes]

> node --version; npm --version; awsmobile --version
v10.5.0
6.1.0
1.1.4

[jbarwick]

it means, you don't have catch!

    var promise = dynamodb.get(getItemParams).promise();

    promise.then(function(data) {
    })
    .catch(function(err) {
        console.log('ERROR: ' + JSON.stringify(err));
    });

Don't forget to catch.

This one: TypeError: Cannot read property 'lastPushSuccessful'

somone else will have to give you the answer to that one. This variable doesn't appear in any of my project files.

try deleting the #current-backend-info folder and do a 'awsmobile pull' again.

[dan1elhughes]

@jbarwick Yup, I'm familiar with .then/.catch, but it's in the CLI so there's nowhere to add the catch unless I go digging around in the source.. Which may take me some time to wrap my head around. 😄

[dan1elhughes]

OK I've made some progress, I've found that deleting the /awsmobilejs/backend/appsync directory allows me to successfully awsmobile pull.

However that's not much use as I assume if I run a awsmobile publish now, it'll delete all my appsync work. I can see from version control that before awsmobile pull I have around 350 lines in awsmobilejs/backend/appsync/schema.graphql, but after the pull I have 65 lines which appear to be a default schema set. It also deletes all my resolver mappings.

[UnleashedMind]

The contents inside the folder awsmobilejs/.awsmobile/info is probably manually modified, that's why the cli is complaining because it sees the appsync folder inside awsmobilejs/backend, but it can not find any information about the appsync feature, which is stored in the file awsmobilejs/.awsmobile/info/appsync-info.json

If you could, please tell us the steps that lead to this error, like how appsync is added to the project, what's been edited, and push/pull operations you have done prio to this error. etc. It'd greatly help us to understand issue and investigate further.

[dan1elhughes]

Has there been an update on AWS side on how the CLI communicates? I'm now seeing a flag "lastPushSuccessful": false in awsmobilejs/.awsmobile/info/appsync-info.json, and I'm able to deploy successfully. I don't think I changed anything, other than doing yet another git reset and awsmobile pull. The immediate problem is resolved, but I don't actually know how I resolved it - what does that flag indicate? What adds it to the project, and how come it wasn't being added before?

I'm also getting the following keys deleted from my aws-exports.js when I pull, but I don't think that's new (shall I open a new issue for this?) :

aws_appsync_graphqlEndpoint: '...',
aws_appsync_region: '...',
aws_appsync_authenticationType: '...',

[UnleashedMind]

The appsync feature is not in the aws mobile hub services, it's an experimental add-on in the awsmobile cli, it's not a complete feature.
If you do not use appsync, you should remove everything related to it by executing 'awsmobile features` and de-select the appsync feature.

[UnleashedMind]

close this issue for now, feel free to re-open it or open another one if you see other problems.