Needs some more work to address various places that show that info.

For example the diagnostics quick panel shows some stray : in the list and somewhat weirdly spaced (or unwanted) : in the annotation below the list:

Hover info also missing space in that case:

For reference, diagnostics panel looks like this without source but with code.

I would probably go with a much simpler solution that uses server name (configuration.name) when source is missing. As you can see from my previous comment, your approach is riddled with edge cases because source is entangled with other diagnostic properties.

I'd like to get this behaviour right because there is no need to show a source and getting this behaviour to be closer to VS Code would be better for overall "LSP compliance" I suppose.

Gonna dump some comparisons between LSP 1.20 and VS Code here to highlight the differences.

no "source" or "code"

"code", no "source"

"source" and "code"

I'll try my best to patch this into the LSP plugin.

I'll try my best to patch this into the LSP plugin.

Then maybe LSP should follow VSCode here and use parenthesis for code since it perhaps wouldn't be so clear otherwise when there is code but not source.

Using parenthesis now. Only caveat is that the link in the diagnostics panel includes the parenthesis:

Using parenthesis now. Only caveat is that the link in the diagnostics panel includes the parenthesis:

You should be able to adjust the syntax file to address that.

There should be some contrast between the message and the source/code part since now it looks like part of the sentence.

but the source/code part does appear to be slightly darker? So I didn't introduce this issue.

You should be able to adjust the syntax file to address that.

I don't know what this means. For context, before I patched this plugin, I had no experience with Python or the Sublime API, and I'm still just verifying my changes by opening the .sublime-package in 7zip, replacing the files, and restarting ST.

You should be able to adjust the syntax file to address that.

I don't know what this means.

Actually it's a phantom so it's even easier to change. I'll make a comment in relevant place.

Ignoring the part in red, the annotations on the right of diagnostics don't look very readable with parenthesis. We can't use HTML in that area so we can't adjust contrast here. I wonder whether presenting in this place specifically (or even in every place) should have space before (...

Ignoring the part in red, the annotations on the right of diagnostics don't look very readable with parenthesis. We can't use HTML in that area so we can't adjust contrast here. I wonder whether presenting in this place specifically (or even in every place) should have space before (...

Before & after my changes

Ignoring the part in red, the annotations on the right of diagnostics don't look very readable with parenthesis. We can't use HTML in that area so we can't adjust contrast here. I wonder whether presenting in this place specifically (or even in every place) should have space before (...

You can ignore that part for now. We'll maybe tweak it later.