Improve linters UI by showing progress and not showing results from already closed files

[akrherz]

I love vscode-python and use it all day, every day :) About the only issue I have is how python linters operate.

I previously raised #1941, which remains valid today, but unfortunately was closed by a bot :(

The fundamental issue is that there is no UI indication that a configured python linter is currently in-progress. When I save a file, I have no idea if the linter completed without any found issue or if it is still running. Often, I close the file to only have the linter content appear in the Problems tab without any means to remove that content. I have to re-open that file. Save it, wait until the Problem content appears again and then close to file to remove the Problems tab content. This is aggravating :)

My UI suggestions:

1. When a linter is running, have the filename appear in the Problems tab with some spinner showing something is happening.
2. When the linter returns results, don't show this content if the file is no longer open in the editor!

Thank you for the consideration.

[karthiknadig]

Note that we are working on this (#17235 ) which should address both of these concerns. Closing this in favor of #17235

When a linter is running, have the filename appear in the Problems tab with some spinner showing something is happening.

For this part of the request, with #17235, linting will occur over LSP (Language Server Protocol). This might be something that we will have to take up with VS Code after we see how the experience is. Currently the reason you see a delay is because we launch a separate python process each time we need to lint. There is a lot of overhead with the way we do things now. With the linter-behind-LSP the linter will run like a server, so the process over head should go away. Additionally, all the linter modules should be loaded and ready to go by the first call to the linter. So, it should be faster. But if we see that even with LSP, it can take a long time, then we can definitely make a recommendation to VS Code to have some UI indication when there are pending calls to the server.