MiddlewareStacks added to commands in lib-dynamodb never get applied.

[c0pp3rt0p]

Describe the bug

Commands in lib-dynamodb do not add their middelwareStack to the underlying command.

Adding any middleware stack to a command in the lib-dynamodb package has no effect.

Your environment

NodeJs/TS on mac

SDK version number

@aws-sdk/package-name@3.43.0

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

no

Details of the browser/Node.js/ReactNative version

$ node -v
v14.17.0

Steps to reproduce

Please share code or minimal repo, and steps to reproduce the behavior.

import { QueryCommand } from '@aws-sdk/lib-dynamodb';
import { dynamoDocClient } from './dynamodb-client';

        const cmd = new QueryCommand({
          TableName: "MyTable",
          KeyConditionExpression: "id = :id",
          ExpressionAttributeValues: {
            ':id': id,
          },
        });
        cmd.middlewareStack.add(
          (next) => async (args) => {
            console.log('You will never see this');
            const result = await next(args);
            // result.response contains data returned from next middleware.
            return result;
          },
          {
            step: 'build',
            name: 'addFooMetadataMiddleware',
            tags: ['METADATA', 'FOO'],
          }
        );
      const dynamoDocClient = await client.send(cmd);
      // 

Observed behavior

The expected console output "You will never see this", is never shown.

Expected behavior

when the command is sent "You will never see this" should be output to the console.

Additional context

It appears the commands in lib-dynamodb are missing the step to concat the current middleware with the newly constructed command. Only the client middlewares get resolved. See comments in the code below.

link to relevant code:

aws-sdk-js-v3/lib/lib-dynamodb/src/commands/QueryCommand.ts

Line 83 in e35f78c

const handler = command.resolveMiddleware(clientStack, configuration, options);

resolveMiddleware(clientStack, configuration, options) {
        const { marshallOptions, unmarshallOptions } = configuration.translateConfig || {};
        const command = new client_dynamodb_1.QueryCommand(utils_1.marshallInput(this.input, this.inputKeyNodes, marshallOptions));
       // need to concat the current middlewareStack with the constructed client.
        const stack = clientStack.concat(this.middlewareStack);
       // resolve the newly combined stack
        const handler = command.resolveMiddleware(stack, configuration, options);
        return async () => {
            const data = await handler(command);
            return {
                ...data,
                output: utils_1.unmarshallOutput(data.output, this.outputKeyNodes, unmarshallOptions),
            };
        };
    }

[yenfryherrerafeliz]

Hi @c0pp3rt0p, thanks for opening this issue. After looking into this, I found that the problem is caused because when the QueryCommand instance that you have created, which implementation is defined in lib-dynamodb package, create a new instance of the QueryCommand, but of the implementation that is defined in client-dynamodb package, and this new instance is used as the final command to be executed, but just the inputs you provided are given to this new command instance. This means that the middleware stack from the first command instance is ignored.
We can see what I explained above in the following line.

I will mark this issue to be reviewed so we can address this further.

Here is the code that I used to reproduce:

import {DynamoDBDocumentClient, QueryCommand} from "@aws-sdk/lib-dynamodb";
import {DynamoDBClient} from "@aws-sdk/client-dynamodb";

const client = DynamoDBDocumentClient.from(new DynamoDBClient({
    region: 'REGION',
}));
const queryCommandParams = {
    TableName: "test-table",
    KeyConditionExpression: "id = :id",
    ExpressionAttributeValues: {
        ':id': 'id',
    },
};
const queryCommand = new QueryCommand(queryCommandParams);
queryCommand.middlewareStack.add((next) => async (args) => {
        console.log('We should see this output!');
        // result.response contains data returned from next middleware.
        return await next(args);
    },
    {
        step: 'build',
        name: 'addFooMetadataMiddleware',
        tags: ['METADATA', 'FOO'],
    }
);
const response = await client.send(queryCommand);

console.log('Response: ', response);

/**
 * Suggestion:
 *  Since middlewareStack is a readonly variable, we can not override the middlewareStack of the new command instance
 *  with the middlewareStack of the first command instance created. We could maybe create an array in
 *  QueryCommand of lib-dynamodb package, which will hold all the middleware functions provided, and then we
 *  just need to add those functions to the middlewareStack of the final command to be executed. For example:
 *      
 *   New function:
 *      public addToMiddlewareStack(middleware) {
 *          this.middlewareStackItems.push(middleware);
 *      }
 *      
 *   And in the resolveMiddleware function:
 *      const { marshallOptions, unmarshallOptions } = configuration.translateConfig || {};
 *      const command = new __QueryCommand(marshallInput(this.input, this.inputKeyNodes, marshallOptions));
 *
 *      for (let item of this.middlewareStackItems) {
 *          command.middlewareStack.add(item);
 *      }
 *      const handler = command.resolveMiddleware(clientStack, configuration, options);
 *      
 *   And how to use it:
 *      const queryCommand = new QueryCommand(queryCommandParams);
 *      queryCommand.addToMiddlewareStack((next) => async (args) => {
 *              console.log('We should see this output!');
 *              // result.response contains data returned from next middleware.
 *              return await next(args);
 *          },
 *          {
 *              step: 'build',
 *              name: 'addFooMetadataMiddleware',
 *              tags: ['METADATA', 'FOO'],
 *          }
 *      );
 *      
 */

Thanks!

[yenfryherrerafeliz]

@c0pp3rt0p As workaround, you could add the middleware to the client instead. Please see my code below:

import {DynamoDBDocumentClient, QueryCommand} from "@aws-sdk/lib-dynamodb";
import {DynamoDBClient} from "@aws-sdk/client-dynamodb";

const client = DynamoDBDocumentClient.from(new DynamoDBClient({
    region: 'us-east-2',
}));
client.middlewareStack.add((next) => async (args) => {
        console.log('We should see this output!');
        // result.response contains data returned from next middleware.
        return await next(args);
    },
    {
        step: 'build',
        name: 'addFooMetadataMiddleware',
        tags: ['METADATA', 'FOO'],
    }
);
const queryCommandParams = {
    TableName: "test-table",
    KeyConditionExpression: "id = :id",
    ExpressionAttributeValues: {
        ':id': 'id',
    },
};
const queryCommand = new QueryCommand(queryCommandParams);
const response = await client.send(queryCommand);

console.log('Response: ', response);

Here is the output:

We should see this output!
Response:  {
  '$metadata': {
    httpStatusCode: 200,
    requestId: 'REQUEST-ID',
    extendedRequestId: undefined,
    cfId: undefined,
    attempts: 1,
    totalRetryDelay: 0
  };