for ES6+ module settings, REPL error on first command: Unexpected token 'export'

[yilmazdurmaz]

Search Terms

REPL
Unexpected token 'export'

#1563 has it, describes wrong, closed with no fix.

Expected Behavior

When ts-node starts with ES6+ module types, it behaves as usual as pre-ES6 module types, which is having a smooth "undefined" message upon pressing "enter" key the first time with an empty line or having some result if there is an actual command.

Actual Behavior

When ts-node starts with ES6+ module types, the first line results in an error whether full or empty (empty line gives ...<repl>.ts:2)

c:\Workspace\test>npx ts-node
> console.log("hello")         <===== first command results in error
c:\Workspace\test\<repl>.ts:3
export {};
^^^^^^

Uncaught SyntaxError: Unexpected token 'export'
> console.log("hello")        <===== later commands do not seem to have the problem
hello
undefined
>

Steps to reproduce the problem

• create an empty folder, open a terminal and invoke npm install ts-node
• create a new tsconfig.json with the following content

{
    "compilerOptions": {
      "target": "ESNext",
      "module": "ESNext",
      "moduleResolution": "NodeNext"
}

• start REPL with npx ts-node
• just press enter or try some command if you want. the first press on "enter" will result in this error

Minimal reproduction

above are the minimal steps

Specifications

ts-node v10.9.1
node v18.9.0
compiler v4.8.4

• ts-node version:
• node version:
• TypeScript version:
• tsconfig.json, if you're using one:

{
    "compilerOptions": {
      "target": "ESNext",
      "module": "ESNext",
      "moduleResolution": "NodeNext"
    }
}

• package.json: (having "type":"module" has no effect)

{
  "dependencies": {
    "ts-node": "^10.9.1"
  }
}

• Operating system and version: Windows 10 21H2
• If Windows, are you using WSL or WSL2?:

[cspotcode]

Seems related to #1752

[yilmazdurmaz]

Seems related to #1752

I cannot say if it is so. You know its content better and way better than I to relate 😅

But I tested and having "type":"module" in "package.json" file does not give this error I got. It seems it needs "tsconfig.json"

[wvhulle]

What is the solution?