Import error when using node + tsc

[ex-daniel-graupner]

I installed ventojs via npm. My project uses nodejs v22.17 and typescript.

tsconfig includes the following compiler options:

{
  "compilerOptions": {
    "declaration": false,
    "importHelpers": true,
    "module": "Node16",
    "moduleResolution": "node16",
    "target": "es2022",
    "outDir": "dist",
    "rootDir": ".",
    "strict": true,
    "esModuleInterop": true,
    "sourceMap": true,
    "forceConsistentCasingInFileNames": true
  }

I just added file VentoTest.ts with one line: import vento from "ventojs".

Compiling with tsc throws errors:

node_modules/ventojs/types/core/environment.d.ts:1:23 - error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './tokenizer.js' instead?

1 import { Token } from "./tokenizer.d.ts";
                        ~~~~~~~~~~~~~~~~~~

node_modules/ventojs/types/mod.d.ts:1:42 - error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './core/environment.js' instead?

1 import { Environment, type Loader } from "./core/environment.d.ts";
                                           ~~~~~~~~~~~~~~~~~~~~~~~~~

How can I use ventojs with node + typescript?

[oscarotero]

It works fine with the TypeScript native support of Node.
I'm not sure how are you executing it. Can you try adding this configuration to the compiler options?

{
  "compilerOptions": {
    "verbatimModuleSyntax": false,
  }
}

[ex-daniel-graupner]

Thanks for your support.

The project I am working on is quite old and does not use the native TS support. I might consider this but at the moment it works still fine using the typescript compiler. Running typescript natively with node seems to have limitations.

Unfortunately, setting verbatimModuleSyntax to false does not help, I get the same error messages.
I am using several dependencies, with and without TS types they work fine but I do not really understand how ventojs is different.

[oscarotero]

The error is because Token and Environment must be imported with the type keyword, and, for some reason, it's not included (example: https://cdn.jsdelivr.net/npm/ventojs@2.3.0/types/mod.d.ts)

This is the script to transpile the code to NPM: https://github.com/ventojs/vento/blob/main/_scripts/build_npm.ts
Maybe I'm missing something?

Another option is just use the original .ts files. You can download the files in a folder and just import them. Vento doesn't have dependencies, so it would be easy to do it.

[ex-daniel-graupner]

OK, it seems to be time for a little refactoring. I changed my app to use native typescript support from node. Ventojs now works as expected.

Thanks again for the hint on native node TS support.

[ex-daniel-graupner]

I reopened the issue, my app is running with ventojs. However, the errors still appear when using tsc.

This is a valid scenario. Although tsc does not emit hs files, it is used in vs code to check typescript syntax in the editor.

[ex-daniel-graupner]

The error is gone with the following changes

ventojs\types\mod.d.ts

import { Environment, type Loader } from "./core/environment.ts";

ventojs\types\core\environment.d.ts

import { Token } from "./tokenizer.ts";

So the change is to include .ts instead of .d.ts. I am not sure if this is correct in general. What do you think?