UPDATE_FAILED: GraphQlSchema Property Validation Failure

[fetree]

I am upgrading from version 1 to version 2.2.0. I have followed the doc to upgrade and want to use js resolvers.
I am getting an error that swaps between

Property validation failure: [Length of value for property {/Definition} is less than minimum allowed length {1}]```

and

```CREATE_FAILED: GraphQlDs27 (AWS::AppSync::DataSource)
Property validation failure: [Value for property {/Name} does not match pattern {[_A-Za-z][_0-9A-Za-z]*}]```

Configuration for resolver: 

```'Query.getStuff': {
        functions: [
          {
            dataSource: 'dynamoDbDataSource,
            code: 'mapping-templates/getStuff.js',
          },
        ],
      },```

When using request/response and using a vtl file it is able to deploy

[AlexHladin]

Hello @fetree
Please add an example of your datasource. Potentially, you used the wrong name for the datasource.