# Error Cannot find module '//../cursor' - while trying to use mongo javascript driver

**URL:** <https://forum.serverless.com/t/error-cannot-find-module-cursor-while-trying-to-use-mongo-javascript-driver/7163>\
**Category:** Serverless Framework\
**Tags:** aws, lambda\
**Created:** [January 24, 2019, 10:08am UTC](https://forum.serverless.com/t/error-cannot-find-module-cursor-while-trying-to-use-mongo-javascript-driver/7163 "2019-01-24T10:08:50Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![EnricoPicci](https://avatars.discourse-cdn.com/v4/letter/e/ba9def/32.png) [@EnricoPicci](https://forum.serverless.com/u/EnricoPicci)\
**Post date:** [January 24, 2019, 10:08am UTC](https://forum.serverless.com/t/error-cannot-find-module-cursor-while-trying-to-use-mongo-javascript-driver/7163/1 "2019-01-24T10:08:50Z")

</div>

I have a series of services that I deploy on AWS Lamba Node using **serverless** framework using the **webpack** plugin for serverless. The code is written in **Typescript**.

One of the services uses **mongo javascript** client. This is the **handler.ts** code, pretty basic indeed

```auto

export const getDocs = (event: APIGatewayEvent, context: Context, callback: Callback) => {
    context.callbackWaitsForEmptyEventLoop = false;

    MongoClient.connect('mongoConnectionString', function(err, client) {
      if (err) {
        callback(err, null);
      }
      const db = client.db('mydb');
      db.collection('mycollection').find().toArray()
      .then(
        val => callback(null, JSON.stringify(val)
      );
    });
  
};

```

When I try to execute the service which uses the **mongo** driver I get an error. Looking at the log trace on Lambda I see the following message

`Error: Cannot find module '//../cursor'`

Other services that do not use Mongo actually work fine, and the service using **mongo** works also fine if it is invoked in a Node server, which makes me think that the problem is around how **serverless** and the rest of the components actually interact.

Here is the **serverless.yml**

```auto

provider:
  name: aws
  runtime: nodejs6.10

  hello12:
    handler: handler.hello12
    events:
      - http:
          path: hello12/get
          method: get

package:  
    individually: true
    
plugins:  
   - serverless-webpack
   - serverless-offline

```

The **webpack.conifg.js** file is pretty standard and is the same I have successfully used other times to deploy services which use mongo javascript client.

```auto

module.exports = {
  devtool: 'source-map',
  entry: slsw.lib.entries,
  resolve: {
    extensions: [
      '.js',
      '.json',
      '.ts',
      '.tsx'
    ]
  },
  output: {
    devtoolModuleFilenameTemplate: '[absolute-resource-path]',
    libraryTarget: 'commonjs',
    path: path.join(__dirname, '.webpack'),
    filename: '[name].js'
  },
  target: 'node',
  module: {
    rules: [
      {
        test: /\.ts(x?)$/,
        use: [
          {
            loader: 'ts-loader'
          }
        ],
      }
    ]
  }
};

```

Also **tsconfig.json** seems pretty innocuous.

```auto
    "compilerOptions": {
        "target": "es6",
        "module": "commonjs",
        "outDir": "dist",
        "sourceMap": true,
        "allowJs": true,  
        "noUnusedLocals": true,  
        "noUnusedParameters": true   
    },
    "include": [
        "*.ts",
        "src/*.ts",
        "routes-express/*.ts",
        "src/**/*.ts"
    ],
    "exclude": [
        "node_modules"
    ],
    "typeRoots": [
        "node_modules/@types"
    ],
    "lib": [
        "es2016",
        "dom"
    ]
}

```

The versions of the various components are

- serveless version 1.36.2
- webpack version 4.29.0
- serverless-webpack version 5.2.0
- mongodb version 3.1.12
- typescript version 2.7.2

To complete the scenario, if I remove the use of **webpack** I get the following error in the **lambda** trace

`Unable to import module 'handler': Error at Function.Module._resolveFilename (module.js:469:15) at Function.Module._load (module.js:417:25) at Module.require (module.js:497:17) at require (internal/module.js:20:19)`

Any suggestion on where to look at would be very much appreciated.