TypeError: UpdateCommand is not a constructor - AWS SDK v3 for nodejs unit test with jest

Question

I keep getting "TypeError: UpdateCommand is not a constructor" when the unit test reaches the stage where it is calling the UpdateCommand from @aws-sdk/lib-dynamodb. I think it is the mock that has issue. Not really sure where to go from here

jest.mock('@aws-sdk/client-dynamodb', () => {
    return {
      DynamoDBClient: jest.fn().mockImplementation(() => {
        return {}
      }),
    };
  });
  jest.mock('@aws-sdk/lib-dynamodb', () => {
    return {
      DynamoDBDocumentClient: {
        from: jest.fn().mockImplementation(() => {
          return {
            send: jest.fn().mockImplementation((command) => {
              let res = ''
              if (command.name === 'GetCommand') {
                res = {
                  Item: {
                    data: 'data',
                  }
                }
              }else if (command.name === 'UpdateCommand' || command.name === 'PutCommand') {
                res = { TableName: 'tableName', Item: { PK: 'pk', SK: 'sk' } }
              }
              else if (command.name === 'QueryCommand') {
                res = {
                  Items:[
                  {
                      "data":"data"
                  }
                ]
              }
              }
              return Promise.resolve(res)
            })
          }
        })
      },
      GetCommand: jest.fn().mockImplementation((cmdPayload) => {
        if (cmdPayload.Key.PK === 'pk') {
          return { name: 'GetCommand' }
        }
        return undefined
      }),
      PutCommand: jest.fn().mockImplementation(() => {
        return { name: 'PutCommand' }
      }),
      UpdateCommand: jest.fn().mockImplementation((cmdPayload) => {
        return { name: 'UpdateCommand' }
      }),
      QueryCommand: jest.fn().mockImplementation((cmdPayload) => {
        // ensure valid api name in mock table
        if (cmdPayload.ExpressionAttributeValues[':ct'] === 'test') {
          return { name: 'QueryCommand' }
        }
        return undefined
      })

    }
})

Tried clean npm install but no luck. Would really appreciate any inputs on this.

Thanks in advance!

Answer 1

I'm not familiar with your style of mocking but the parameters you pass to UpdateCommand are not correct, unlike PutCommand it does not take Item as parameter.

https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/UpdateCommand/