plainToClass does not convert a Date to string

Question

According to the docs a Date object should be converted to a string:

Note, that dates will be converted to strings when you'll try to convert class object to plain object.

My example-code with class-transformer 0.2.3 does not work as expected:

class TestDate {
  @Type(() => Date)
  aDate!: Date;
}

  const testDate = new TestDate();
  testDate.aDate = new Date();
  const result: any = classToPlain(testDate);
  console.log(typeof result.aDate);

This prints object to the console, but I'd expect string.
What am I missing?

Answer 1

The following sentence in the documentation is wrong (see class-transformer#326):

Note, that dates will be converted to strings when you'll try to convert class object to plain object.

The solution is to use @Transform:

  @Transform(value => (value as Date).toISOString(), {
    toPlainOnly: true
  })

Codesandbox example with workaround