Test invocations fail on pure-Dart files in Flutter project

[amake]

In an effort to support running tests in pure-Dart projects (because you may want to work on a pure-Dart project for use in a Flutter project), we try to be smart about which invocation to use: flutter test or pub run test.

But we are not smart enough: we assume a Flutter project only if the file has a import package:flutter(_test)?/... statement, and otherwise assume a Dart project.

This falls down for pure-Dart files in Flutter packages.

We need some cheap way of determining whether the project is a Flutter one or not.

[ericdallo]

The way VSCode dart extension and lsp-dart handles this is checking the pubspec.yml file on project root then searching for a flutter SDK regex dependency :)
https://github.com/emacs-lsp/lsp-dart/blob/master/lsp-dart-utils.el#L44-L51

[amake]

Thanks! Yeah I was hoping for something possible without reading the contents of any files, but that does seem to be the most foolproof way.

[ericdallo]

Yeah, me too 😅 , but it seems to be working very well for VSCode