helmet() is not a function

[JeffreyArt1]

I'm currently using Nest.js 8.1.5.

I have tested helmet 4.6.0 and 5.0.1 with the same results.

This is my server file:

import { NestFactory } from '@nestjs/core'
import helmet from 'helmet';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  app.enableCors();
  app.use(helmet());

  await app.listen(AppModule.applicationPort);
}

bootstrap()

When I try to run it, it prints this to console.

TypeError: (0 , helmet_1.default) is not a function
    at bootstrap (/Users/jeffreymesa/Desktop/dev.nosync/yp-micro/yp-lottery-api-gateway/src/main.ts:14:17)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)

[EvanHahn]

Sorry you're running into this. What does your tsconfig.json look like?

[daniel-ackermann]

I have the same error. I use Nestjs 8.2.5 with this tsconfig.json:

{
  "compilerOptions": {
    "module": "commonjs",
    "declaration": true,
    "removeComments": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "allowSyntheticDefaultImports": true,
    "target": "es2017",
    "sourceMap": true,
    "outDir": "./dist",
    "baseUrl": "./",
    "incremental": true,
    "skipLibCheck": true,
    "strictNullChecks": false,
    "noImplicitAny": false,
    "strictBindCallApply": false,
    "forceConsistentCasingInFileNames": false,
    "noFallthroughCasesInSwitch": false
  }
}

[EvanHahn]

In the short term, you can do one of the following:

1. Try import helmet = require('helmet')
2. Enable esModuleInterop in your tsconfig
3. Downgrade to Helmet v4

In the long term, I'll look into what's causing this. I suspect it will be fixed in an upcoming version (see #345), but I have been busy with other things and haven't had time to look yet. Apologies!

[daniel-ackermann]

Thank you for your fast solution! That works fine for me!

And sorry for the duplication of #344

[JeffreyArt1]

Sorry you're running into this. What does your tsconfig.json look like?

mine looks like this:

{
  "compilerOptions": {
    "module": "commonjs",
    "declaration": true,
    "removeComments": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "allowSyntheticDefaultImports": true,
    "target": "es2017",
    "sourceMap": true,
    "outDir": "./dist",
    "baseUrl": "./",
    "incremental": true,
    "skipLibCheck": true,
    "strictNullChecks": false,
    "noImplicitAny": false,
    "strictBindCallApply": false,
    "forceConsistentCasingInFileNames": false,
    "noFallthroughCasesInSwitch": false
  }
}

I recently added allowSyntheticDefaultImports to see if that could be a solution.

[JeffreyArt1]

In the short term, you can do one of the following:

1. Try import helmet = require('helmet')
2. Enable esModuleInterop in your tsconfig
3. Downgrade to Helmet v4

In the long term, I'll look into what's causing this. I suspect it will be fixed in an upcoming version (see #345), but I have been busy with other things and haven't had time to look yet. Apologies!

These solutions worked for me with helmet 4.6.0:

• import helmet = require('helmet')
• import * as helmet from 'helmet'

Tried using esModuleInterop in my tsconfig (with version 5) with no luck :(

[EvanHahn]

This should be fixed in an upcoming version. Please stay tuned!

[EvanHahn]

I just released helmet@5.0.2 which should fix this problem. Please try updating to see if that fixes things for you!

[JeffreyArt1]

Upgraded and tested, so far so good. Thanks!