Using with Typescript

[ballcoach12]

My apologies if this question is off topic.

I am following the example on the main readme.md. When I import as in the example code in a unit test ts file:

import { addSchema, validate, } from '@hyperjump/json-schema/draft-2020-12';

I get the following error:

SyntaxError: Cannot use import statement outside a module

I recognize that this is related to different module formats, but I'm not exactly sure how to resolve it. I have tried making modifications to my package.json file and to my tsconfig.json file, but I still can't get past the error.

[ballcoach12]

As a follow-up, there seems to be some issue with how Jest compiles the code. I have the following configuration in jest.config.js, which works for other dependencies that I import, but not for json-schema:

module.exports = {
  preset: 'ts-jest',
  testEnvironment: 'node',
  transform: {
    '^.+\\.ts?$': 'ts-jest',
  },
  transformIgnorePatterns: ['<rootDir>/node_modules/'],
};

[jdesrosiers]

This is really a TypeScript configuration issue, which is not something I have a lot of knowledge about, but I'll do my best to help.

Here's the setup that I use for running one-off TS code with npx tsx myscript.ts. This configuration compiles the code to ESM so it can get executed by a node project configured to use ESM.

tsconfig.json

{
  "compilerOptions": {
    "module": "es2020",
    "target": "es2015",
    "moduleResolution": "Node16",
    "esModuleInterop": true,
    "strict": true
  }
}

I don't remember what all of those things do, but iirc, "moduleResolution": "Node16" is the magic incantation that I was missing when I was in your position trying to get all the pieces to line up properly.

package.json

{
  ...
  "type": "module",
  ...
}

This sets the node project to use ESM instead of the default CommonJS. If you want/need your node project to use CommonJS instead, I think you'd need to remove "type": "module" and change "module" to "commonjs". But, that's just a guess. I don't have a working example to say for sure.

[jdesrosiers]

For mocha I had to configure a "loader" specifically for supporting ESM libraries. There might be some similar configuration for Jest.

[GabenGar]

If your code runs through a bundler (aka any transpilation tool which is not typesript), then you should try running with "moduleResolution": "bundler" first. This might or might not fix your specific problem, but worth a try when shooting in the dark.