Can somebody explain this code

[logrusx]

I'm trying to migrate nvim-java to Mason 2.0 but I'm finding some difficulties understanding the current code.

Can somebody explain what's the difference between

utils.mason:

function M.is_available(package_name, package_version)
	local has_pkg = mason_reg.has_package(package_name)

	if not has_pkg then
		return false
	end

	local has_version = false

	local pkg = mason_reg.get_package(package_name)
	pkg:get_installed_version(function(success, version)
		if success and version == package_version then
			has_version = true
		end
	end)

	return has_version
end

and

function M.is_installed(package_name, package_version)
	local pkg = mason_reg.get_package(package_name)
	local is_installed = pkg:is_installed()

	if not is_installed then
		return false
	end

	local installed_version
	pkg:get_installed_version(function(ok, version)
		if not ok then
			return
		end

		installed_version = version
	end)

	return installed_version == package_version
end

and why is there so much code duplication:

function M.is_outdated(packages)
	for _, pkg in ipairs(packages) do
		if not M.is_available(pkg.name, pkg.version) then
			return true
		end

		if not M.is_installed(pkg.name, pkg.version) then
			return true
		end
	end
end

I don't see those used anywhere else, why isn't the logic directly in is_outdated? And why are those functions 90% identical? Especially after being migrated I struggle to find the difference and why there are two of them doing almost the same.

[defields923]

pkg:is_installed might throw if get_package returns a nil value, but yeah, a check on the pkg before is_installed could mitigate that. That's the only significant difference I see. Not sure if that's even possible,, considering it's being called within that loop on the packages within is_outdated, but maybe there are other uses elsewhere that aren't guaranteed?

[logrusx]

Hello, thanks for taking the time to comment.

pkg:is_installed might throw if get_package returns a nil value,

No, get_package won't return nil, it'll error, but that part is clearly stated in Mason's release notes. It's mitigated by using pcall, the same way they did in Mason's implementation of has_package.

but yeah, a check on the pkg before is_installed could mitigate that.

That part is not entirely correct. It's not about if the package is installed but if it at all exists in the registry. Only later it's about if the package is installed and that part is clear and doesn't need change. I rewrote it in less and more clear code though.

What's not clear is the intention of the author. It looks like they wanted to do version management but it's implemented in an unclear way.

That's the only significant difference I see. Not sure if that's even possible,, considering it's being called within that loop on the packages within is_outdated, but maybe there are other uses elsewhere that aren't guaranteed?

There aren't other uses but that's not the problem. That part of the code is already done and even works on its own, but there are other issues around, which are not obvious.

I guess that's the reason an attempt to migrate it was reverted. Although that attempt might have been problematic on its own as it didn't take into account what you said above and it didn't guard get_package with pcall.

Now I'm struggling to debug the startup of the plug-in to find out where the not obvious issues are, because there's no debug or logging output whatsoever and I know for sure the error output is suppressed somehow, because I had errors and they popped up for the functions above when I debugged it. It was easy, I just copied the file in .config/nvim/lua and commented some stuff and it was easy but the same does not work with the whole plug-in. In the same time debugging examples on the Internet and lazy.nvim documentation do not show how to debug the plug-in and it's startup. Now I'm trying to copy the files similarly to what I did for mason.lua. I would really appreciate any advice on that.

[logrusx]

I've now moved past this topic, that part is already migrated, tested and works well.