Prevent creating empty .ropeproject with null conf

[karimbenbourenane]

When ropeFolder is defined in the configuration but set to null (as would happen with a default config generated by e.g. Zed editing a python file), avoid creating an empty and unused .ropeproject directory. This change completes what I think was the goal of https://github.com/python-lsp/python-lsp-server/pull/604/files, where "ropeFolder": null in the configuration still generates an empty and unused .ropeproject folder.

[ccordoba12]

Hey @karimbenbourenane, thanks for your contribution! I have a quick question for you: how is this different from #604?

Also, pinging @osiewicz about this (the author of #604). What do you think about this one?

[osiewicz]

I sketched up a quick example of playground, but I feel like that'd regress us to before #604 (where you wouldn't be able to pass in null?)?
https://www.online-python.com/Qg4WIZrYfk
I guess the bug might be in Zed and not in pylsp.

[karimbenbourenane]

Hey @karimbenbourenane, thanks for your contribution! I have a quick question for you: how is this different from #604?

Also, pinging @osiewicz about this (the author of #604). What do you think about this one?

It's different in that, the default configuration with zed will be "ropeFolder": null. In #604, this means that despite an explicitly stated null ropeFolder, it will generate an empty and unused .ropeproject directory any time the pylsp is used for example editing a python file. The change I submitted does not do that.

[karimbenbourenane]

@ccordoba12 see the case where rope_config = {"ropeFolder": None}

In #604 the condition passes and the .ropeproject ends up getting generated anyway because of Project(self._root_path, ropefolder=None) being executed. In this proposed change (#664) None does not get passed as a named argument for ropeFolder when "ropeFolder" is a key in the rope_config with value set to None.

[osiewicz]

We do want to pass in None as a ropefolder argument though, as that's what disables creation of a Rope cache.. Please see: https://github.com/python-rope/rope/blob/a32584f5742c093b10437f8da13bfefddb19c155/rope/base/project.py#L260 and the constructor:
https://github.com/python-rope/rope/blob/a32584f5742c093b10437f8da13bfefddb19c155/rope/base/project.py#L198C45-L198C55
https://github.com/python-rope/rope/blob/a32584f5742c093b10437f8da13bfefddb19c155/rope/base/project.py#L227
https://github.com/python-rope/rope/blob/a32584f5742c093b10437f8da13bfefddb19c155/rope/base/project.py#L259