vscode-test - error when calling runTests

Its the first time im trying to set up tests for my vscode extension.

I basically just copy pasted the example from /working-with-extensions/testing-extension from code.visualstudio.

I can't call runTests because of the following error:

error TS2345: Argument of type '{ extensionDevelopmentPath: string; extensionTestsPath: string; }' is not assignable to parameter of type 'TestOptions | ExplicitTestOptions'.
  Object literal may only specify known properties, and 'extensionDevelopmentPath' does not exist in type 'TestOptions | ExplicitTestOptions'.

and that's my code:

import * as path from 'path';

import { runTests } from 'vscode-test';


async function main() {
    try {
        const extensionDevelopmentPath = path.resolve(__dirname, '../../../');

        const extensionTestsPath = path.resolve(__dirname, './suite/index');

        await runTests({ extensionDevelopmentPath, extensionTestsPath });

    } catch(err) {
        console.error('Failed to run tests.');
        process.exit(1);
    }
}


main();

I can't find a mistake and would be grateful for any help.