Tuple type with generic length creates errors with ts-node

[aurerua]

This following code:

type TupleOf<T, N extends number> = N extends N ? (number extends N ? T[] : _TupleOf<T, N, []>) : never;
type _TupleOf<T, N extends number, R extends unknown[]> = R["length"] extends N ? R : _TupleOf<T, N, [T, ...R]>;

type ThreeStrings = TupleOf<string,3>

const threeStrings = ['one', 'two', 'three']

works in the TS Playground and shows no error in vscode but it creates errors when ts-node is run:

error TS2315: Type '_TupleOf' is not generic.

9 type TupleOf<T, N extends number> = N extends N ? (number extends N ? T[] : _TupleOf<T, N, []>) : never;
                                                                              ~~~~~~~~~~~~~~~~~~
10 type _TupleOf<T, N extends number, R extends unknown[]> = R["length"] extends N ? R : _TupleOf<T, N, [T, ...R]>;
        ~~~~~~~~
10 type _TupleOf<T, N extends number, R extends unknown[]> = R["length"] extends N ? R : _TupleOf<T, N, [T, ...R]>;
                                                                                         ~~~~~~~~~~~~~~~~~~~~~~~~~

Is there an easy explanation to that behavior?

[cspotcode]

Do the versions match? ts-node -vv?

Does the behavior change with ts-node --files enabled?

[cspotcode]

Problem was using a different TS version on the playground than was installed locally.

[aurerua]

Thanks for the suggestions.

How are the versions supposed to match? Here is what I get:

$ ts-node -vv
ts-node v9.0.0
node v14.16.0
compiler v4.0.5

And ts-node --files does not help:

{
diagnostics: [
    {
      file: [SourceFileObject],
      start: 345,
      length: 18,
      messageText: "Type '_TupleOf' is not generic.",
      category: 1,
      code: 2315,
      reportsUnnecessary: undefined,
      reportsDeprecated: undefined
    },
    {
      file: [SourceFileObject],
      start: 379,
      length: 8,
      messageText: "Type alias '_TupleOf' circularly references itself.",
      category: 1,
      code: 2456,
      reportsUnnecessary: undefined,
      reportsDeprecated: undefined
    },
    {
      file: [SourceFileObject],
      start: 460,
      length: 25,
      messageText: "Type '_TupleOf' is not generic.",
      category: 1,
      code: 2315,
      reportsUnnecessary: undefined,
      reportsDeprecated: undefined
    }
  ]
}

[cspotcode]

What version are you using in the playground?

[cspotcode]

The playground shows the same thing for me: Playground link

[aurerua]

You are right. With version 4.0.5 in the playground this is the same issue. Thanks for you help.