Does a function without a return statement always return null in Flutter?

Question

The return type of the following function is Future<File?> and yet the compiler does not complain that there is no return value if the picker did not return a picture.

static Future<File?> takeImage() async {
    PickedFile? pickedFile = await ImagePicker().getImage(source: ImageSource.camera);
    if (pickedFile != null) {
      print('PHOTO TAKEN');
      return File(pickedFile.path);
    } else {
      print('NO PHOTO TAKEN');
    }
  }

Would it not make more sense if I had to return null if the picture wasn't taken?

Does a method without a return statement always return null?

The example above seams to suggest it, and something as simple as this compiles too.

static String? s() {}

Could some one clarify whats going on?

Solution

Thanks to @pskink for pointing me in the right direction.

Straight from the documentation:

Return values
All functions return a value. If no return value is specified, the statement return null; is implicitly appended to the function body.

Comments

[Simon Sot]

void A special type that indicates a value that’s never used. Functions like printInteger() and main() that don’t explicitly return a value have the void return type.

[pskink]

read carefully A tour of the Dart language - section about Functions

[Joel Broström]

It does not work for me running Dart 2.13.0. It wont compile with the error: The body might complete normally, causing ‘null’ to be returned, but the return type is a potentially non-nullable type.