DynamoDB - Cannot read property '0' of undefined

[antoineaws]

Describe the bug

The @aws-sdk/client-dynamodb is throwing an ambiguous error 'Cannot read property '0' of undefined' . I am using sdk v3.8.0. It was working great with the previous sdk using DocumentClient instead.

Your environment

SDK version number

@aws-sdk/client-dynamodb@3.8.0

Is the issue in the browser/Node.js/ReactNative?

Node.js

Details of the browser/Node.js/ReactNative version

Paste output of npx envinfo --browsers or node -v or react-native -v
v14.15.4

Steps to reproduce

Run the following command to start local debugging:
sam local start-api -d 9999

Create a simple dynamo db table and a secondary index.
Create a lambda function with the following code:

const docClient = new DynamoDB({ region: 'ca-central-1' });
const { Items } = await docClient.query({
            TableName: 'MyTable',
            IndexName: 'MyColumnIndex',
            KeyConditionExpression: "MyColumn = :myColumn",
            ExpressionAttributeValues: {
                ":myColumn": parsedBody.myColumn
            },
        });

The table is already created and the index as well. The previous version of the sdk worked fine.

Observed behavior

A clear and concise description of what happens.
An ambiguous error is thrown.
Invalid lambda response received: Invalid API Gateway Response Keys: {'errorType', 'trace', 'errorMessage'} in {'errorType': 'TypeError', 'errorMessage': "Cannot read property '0' of undefined", 'trace': ["TypeError: Cannot read property '0' of undefined", ' at Object.visit (/var/task/node_modules/@aws-sdk/client-dynamodb/dist/cjs/models/models_0.js:1101:40)', ' at serializeAws_json1_0AttributeValue (/var/task/node_modules/@aws-sdk/client-dynamodb/dist/cjs/protocols/Aws_json1_0.js:4612:38)', ' at /var/task/node_modules/@aws-sdk/client-dynamodb/dist/cjs/protocols/Aws_json1_0.js:5074:20', ' at Array.reduce (<anonymous>)', ' at serializeAws_json1_0ExpressionAttributeValueMap (/var/task/node_modules/@aws-sdk/client-dynamodb/dist/cjs/protocols/Aws_json1_0.js:5068:34)', ' at serializeAws_json1_0QueryInput (/var/task/node_modules/@aws-sdk/client-dynamodb/dist/cjs/protocols/Aws_json1_0.js:5544:40)', ' at Object.serializeAws_json1_0QueryCommand (/var/task/node_modules/@aws-sdk/client-dynamodb/dist/cjs/protocols/Aws_json1_0.js:354:27)', ' at serialize (/var/task/node_modules/@aws-sdk/client-dynamodb/dist/cjs/commands/QueryCommand.js:95:30)', ' at /var/task/node_modules/@aws-sdk/middleware-serde/dist/cjs/serializerMiddleware.js:5:27', ' at /var/task/node_modules/@aws-sdk/middleware-logger/dist/cjs/loggerMiddleware.js:6:28']}

Expected behavior

Expected the records to be returned.

Screenshots

N/A

Additional context

N/A

[antoineaws]

I figured it out, the query "ExpressionAttributeValues" were not formatted properly. Maybe we should adjust the typing in typescript to flag this as an error?

The correct way is: note the { S: parsedBody.myColumn }

const { Items } = await docClient.query({
            TableName: 'MyTable',
            IndexName: 'MyColumn',
            KeyConditionExpression: "MyColumn = :myColumn",
            ExpressionAttributeValues: {
                ":myColumn": { S: parsedBody.myColumn }
            },
        });

[ajredniwja]

Hey @antawad, thanks for opening this issue, I believe its more of a client side usage mistake as when using DynamoDb DocumentClient you dont have to mention the attribute type with ExpressionAttributeValues, while with the normal client you would.

The documentClient has been implemented in this version of the SDK as well, see #2097

[jeanlescure]

I had the same issue as @antawad and the Cannot read property '0' of undefined error really gives no pointer as to what us as clients are doing wrong. I agree with his suggestion to update the typescript definition to enforce the valid variations of the S: AttributeValue type signature (i.e 'B' | 'BOOL' | 'BS' | 'L' | 'M' | 'N' | 'NS' | 'NULL' | 'S' | 'SS'.

[github-actions]

Greetings! We’re closing this issue because it has been open a long time and hasn’t been updated in a while and may not be getting the attention it deserves. We encourage you to check if this is still an issue in the latest release and if you find that this is still a problem, please feel free to comment or open a new issue.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs and link to relevant comments in this thread.