Custom array class methods disappear

Current behavior

Custom array class methods disappear:

class MyArray extends Array<number> {
  public toString(): string {
    return 'Custom toString method called!';
  }

  public toDB(): string[] {
    return Array.from(this.map((t) => t.toString()));
  }
  
  public static fromDB(record: string[]): MyArray {
    return new MyArray(...record.map((t) => Number(t)));
  }
}

 // Logs an empty array `[]`
console.log('MyArray:', new MyArray());
// Logs an empty string (calls Array#toString instead of MyArray#toString)
console.log(`MyArray: ${new MyArray().toString()}`); 
// Logs `undefined` (even though I defined a MyArray#toDB method)
console.log('MyArray toDB:', new MyArray().toDB);
// Logs `[Function (anonymous)]` (so static methods are preserved)
console.log('MyArray fromDB:', MyArray.fromDB);

Desired behavior

Cypress should compile that custom MyArray class and it’s methods properly.

// Should log `Custom toString method called!` instead of an empty string
console.log(`MyArray: ${new MyArray().toString()}`); 
// Should log `[Function (anonymous)]` instead of `undefined`
console.log('MyArray toDB:', new MyArray().toDB);

Test code to reproduce

See description above.

Cypress Version

Cypress package version: 8.1.0 Cypress binary version: 8.1.0 Electron version: 12.0.0-beta.14 Bundled Node version: 14.15.1

[sainthkh]

@nicholaschiang Did it solve the problem? If so, we can close the issue.

[sainthkh]

Closing because of the inactivity.