I have a simple project

$ ls -l
total 32
-rw-rw-r-- 1 ocket8888 ocket8888   72 Apr 29 09:30 index.ts
-rw-rw-r-- 1 ocket8888 ocket8888  105 Apr 29 09:31 main.ts
drwxrwxr-x 4 ocket8888 ocket8888 4096 Apr 29 09:26 node_modules
-rw-rw-r-- 1 ocket8888 ocket8888  206 Apr 29 09:27 package.json
-rw-rw-r-- 1 ocket8888 ocket8888 1000 Apr 29 09:26 package-lock.json
-rw-rw-r-- 1 ocket8888 ocket8888  222 Apr 29 09:33 tsconfig.json

In index.ts I export a class, and in main.ts I import that class.

index.ts

export class Testquest {
    constructor(public readonly foo: string) {}
}

main.ts

#!/usr/bin/env node
import { Testquest } from ".";

const a = new Testquest("bar");

console.log(a.foo);

When I try to build this, tsc says:

$ npx tsc
main.ts:2:10 - error TS2459: Module '"."' declares 'Testquest' locally, but it is not exported.

2 import { Testquest } from ".";
           ~~~~~~~~~

  main.ts:2:10
    2 import { Testquest } from ".";
               ~~~~~~~~~
    'Testquest' is declared here.


Found 1 error in main.ts:2

As you can see, however, the class is exported. So I don't know why Typescript is so sure it isn't.

package.json

{
  "name": "ts-export-test",
  "version": "1.0.0",
  "description": "",
  "main": "main.js",
  "type": "module",
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "typescript": "^4.6.4"
  }
}

tsconfig.json

{
  "compilerOptions": {
    "target": "es2016",
    "module": "ES6",
    "moduleResolution": "node",
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "strict": true,
    "skipLibCheck": true
  }
}

Note that importing from the non-existent file ./index.js works, but my linter tells me that the /index.js portion is a "useless path segment", and I know from experience I should be able to import symbols from a directory if it has an index.ts file that exports the symbol - I don't know why that's suddenly not working here.

CodePudding user response：

You are currently read the main.ts with node. Replace the first line with ts-node, to use TypeScript to read it.

Here are 3 ways to handle the error.

1. Remove the first line

The first Shebang is not needed, TS can resolve and handle the file itself.

2. Replace with ts-node

main.ts

#!/usr/bin/env ts-node

3. Another way

Also if you don't want to install ts-node globally: Github: ts-node #73

#!/usr/bin/env -S node -r "ts-node/register"

Please make sure you have install ts-node correctly.

References

GitHub: ts-node

Is there a ts-node hashbang? #298

Shebang support #73

Executables without extension #116

CodePudding user response：

Change type of module to commonjs in your package.json and tsconfig.json

In package.json

change "type": "commonjs",

{
  "name": "ts-export-test",
  "version": "1.0.0",
  "description": "",
  "main": "main.js",
  "type": "commonjs",
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "typescript": "^4.6.4"
  }
}

in tsconfig.json

change "module": "commonjs",

remove "moduleResolution": "node",

{
  "compilerOptions": {
    "target": "es2016",
    "module": "commonjs",
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "strict": true,
    "skipLibCheck": true
  }
}