How to properly use ES6 Modules syntax in Typescript files (NextJS)?-CodePudding

The problem seems circular:

package.json does NOT have type: "module". In this case I get this error when using modules in my typescript files:

An error occured while running the seed command:
/Users/me/code/me/prisma-learning/graphql-nextjs/prisma/seed.ts:1
import { PrismaClient } from '@prisma/client';
^^^^^^

So I add type: "module" in package.json and this is now the error:

An error occured while running the seed command:
TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for 
/Users/me/code/me/prisma-learning/graphql-nextjs/prisma/seed.ts

I just want to use ES6 modules in my TS files. The code is from an official Prisma boilerplate project: https://github.com/prisma/prisma-examples/tree/latest/typescript/graphql-nextjs

CodePudding user response：

It seems that you haven't configured your NextJs project to support typescript:

If you use node seed.ts to run seeder, You need to have ts-node package or compile this file to a regular JS file (using tsc or webpack)
If you use seed.ts file in a page or api of your project, check if you have a tsconfig.json file and typescript is installed as a dev dependency.

If none of them helps, please give more information about your project environments and configurations.

CodePudding user response：

If you look in the package.json for this particual example, you'll see that they have a compiler option specified for ts-node:

    "ts-node": "ts-node --compiler-options \"{\\\"module\\\":\\\"commonjs\\\"}\"",

But for the "seed" command doesn't run it with this option.

So you can just replace:

"prisma": {
    "seed": "ts-node prisma/seed.ts"
  }

with

"prisma": {
    "seed": "npm run ts-node prisma/seed.ts"
  }

and then run npx prisma db seed as documented.