Files documenting static extension methods are not generated.

[simphotonics]

The html files documenting static extension methods are not generated by dartdoc.

$ dart --version
Dart SDK version: 2.12.2 (stable) (Unknown timestamp) on "linux_x64"

$ pub run dartdoc --version
dartdoc version: 0.40.0

To recreate:

1. Create an extension containing at least one static method:

/// Sample extension with a static method
extension StaticExtension on String {
  /// Returns the length of `input`.
  static int count(String input) {
    return input.length;
  }
}

2. Generate the documention:

The following warning is shown:

$pub run dartdoc
Documenting generic_reader...
Initialized dartdoc with 725 libraries in 52.3 seconds
Generating docs for library generic_reader from package:generic_reader/generic_reader.dart...
Validating docs...
   warning: dartdoc generated a broken link to: generic_reader/StaticExtension/count.html
  file:///home/dan/DartProjects/generic_reader
Found 1 warnings and 0 errors.
Documented 1 public library in 2.5 seconds
Success! Docs generated into /home/dan/DartProjects/generic_reader/doc/api

The folder doc/api/generic_reader/StaticExtension is missing.

[jcollins-g]

#2585 might have fixed this, will check

[jcollins-g]

This is a bug, we apparently just never called the generator for the file.

[simphotonics]

Thank you for fixing this issue.