Serverless. Not able to import package in a serverless function

[reflash]

I'm trying to use mongodb from my serverless function, but i keep getting mongoose.plugin is not a function or mongoose.connect is not a function. Seems that the problem is it tries to import mongoose, but doesn't find the package.
Could you please advice on that? is there any working sample that does anything similar?

[reflash]

here's my project structure to give some context.

.
├── README.md
├── api
│   ├── _helpers
│   │   └── util
│   │       └── index.ts
│   ├── package.json
│   ├── tsconfig.json
│   ├── users
│   │   └── [vkid].ts
│   └── yarn.lock
├── now.json
├── package.json
├── src
│   ├── App.css
│   ├── App.tsx
│   ├── index.css
│   ├── index.tsx
│   ├── react-app-env.d.ts
│   └── serviceWorker.js
├── tsconfig.json
├── tslint.json
└── yarn.lock

[reflash]

it turned to be a problem specific to mongoose
import * as mongoose from 'mongoose' is not working, but const mongoose = require('mongoose'); does for some reason

[coetry]

If your function extension ends in .js, then we build it with the latest stable Node.js release which doesn't support the import syntax. If you change your extension to .ts, we transpile the typescript, which does support that syntax 😄

[reflash]

I am actually using typescript files, this doesn't happen with other dependencies for some reason, so seems more like a mongoose issue

[bigsee]

I am having a similar issue when trying to use node-fetch within a serverless function.

now dev successfully builds the functions but cannot find the node-fetch module:

Building @now/node@latest:api/test.js
Installing dependencies...
Built @now/node@latest:api/test.js [529ms]
Building @now/node@latest:api/index.js
Installing dependencies...
Built @now/node@latest:api/index.js [379ms]
Building @now/node@latest:api/enquiry.js
Installing dependencies...
Built @now/node@latest:api/enquiry.js [453ms]
Cannot find module '~/api/node_modules/node-fetch'
Require stack:

• /private/var/folders/v9/xxxxxxxxxxxxxxxxxxx/T/zeit-fun-xxxxxxxxxx/api/enquiry.js
• /private/var/folders/v9/xxxxxxxxxxxxxxxxxxx/T/zeit-fun-xxxxxxxxxx/___now_launcher.js
• /Users/carltonmcfarlane/Library/Caches/co.zeit.fun/runtimes/nodejs/bootstrap.js
  Did you forget to add it to "dependencies" in package.json?

Here is my project structure:

and the package.json within /api:

{
    "name": "api",
    "version": "1.0.0",
    "description": "Serverless API for the project",
    "main": "index.js",
    "scripts": {
        "test": "echo \"Error: no test specified\" && exit 1"
      },
      "author": "bigsee",
      "license": "ISC",
      "dependencies": {
          "node-fetch": "^2.6.0"
     }
}

This is blocking me from testing a POST route locally. Any idea what I'm missing?

[bigsee]

After a bit more digging it seems that the import path at the top of the serverless function was changed at some point from

const fetch = require('node-fetch')

to

const fetch = require('~api/node_modules/node-fetch')

Manually changing back resolves. Perhaps this is VS Code trying to be helpful...