Bug 494139

Summary:	LSP hover text has backslashes before certain characters.
Product:	[Applications] kate	Reporter:	Alex Lowe <lengau>
Component:	general	Assignee:	KWrite Developers <kwrite-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	waqar.17a
Priority:	NOR
Version:	24.08.1
Target Milestone:	---
Platform:	Kubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Kate, showing backspaces before a bunch of special characters Emacs not showing these backslashes Pycharm not showing these backslashes vscode not showing slashes Visual Studio Code not showing backslashes yaml server hover on master

Description Alex Lowe 2024-10-04 22:29:52 UTC

Created attachment 174435 [details]
Kate, showing backspaces before a bunch of special characters

SUMMARY
The hover text from language servers contains backspaces before many special characters, including: .`!#*(){}[]\

STEPS TO REPRODUCE
1. Configure the YAML LSP to enable hover and receive from the schema store:
{
    "servers": {
        "yaml": {
            "command": ["yaml-language-server", "--stdio"],
            "url": "https://github.com/redhat-developer/yaml-language-server",
            "highlightingModeRegex": "^YAML$",
            "settings": {
                "yaml": {
                    "hover": true,
                    "schemaStore": {
                        "enable": true
                    }
                }
            }
        }
    }
}

2. Create a "rockcraft.yaml" file with the following contents:
name: my-name
title: blah
summary: thing
description: description
base: ubuntu@24.04
platforms:
  amd64:
parts: {}

3. Hover over the "name" field

OBSERVED RESULT
Hover text contains several backslashes. For example, the first paragraph reads as: "Valid names for rocks\. It matches the accepted values for pebble layer files:"

EXPECTED RESULT
Hover text does not contain these backslashes. The first paragraph should read: "Valid names for rocks. It matches the accepted values for pebble layer files:"
Compare to Visual Studio Code with the Red Hat YAML LSP extension installed.


SOFTWARE/OS VERSIONS
Operating System: Kubuntu 24.10
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.6.0
Qt Version: 6.6.2
Kernel Version: 6.11.0-8-generic (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7840U w/ Radeon 780M Graphics
Memory: 60.6 GiB of RAM
Graphics Processor: AMD Radeon 780M

ADDITIONAL INFORMATION
The schema for rockcraft.yaml can be found at: https://raw.githubusercontent.com/canonical/rockcraft/main/schema/rockcraft.json

The actual value that comes out of the server at this point, according to lsp-devtools, is:

{
  "jsonrpc": "2.0",
  "id": 3,
  "result": {
    "contents": [
      "Project Name\n\nValid names for rocks\\. It matches the accepted values for pebble layer files:\n\n\\- must start with a lowercase letter \\[a\\-z\\]\n\n\\- must contain only lowercase letters \\[a\\-z\\], numbers \\[0\\-9\\] or hyphens\n\n\\- must not end with a hyphen, and must not contain two or more consecutive hyphens\n"
    ],
    "range": {
      "start": {
        "line": 0,
        "character": 0
      },
      "end": {
        "line": 0,
        "character": 4
      }
    }
  }
}

Comment 1 Waqar Ahmed 2024-10-08 07:42:04 UTC

I wonder if its the server's fault or our fault. If the server escapes markdown characters by putting backslashes, thats how they will appear...

Comment 2 Alex Lowe 2024-10-10 12:59:08 UTC

Created attachment 174623 [details]
Emacs not showing these backslashes

Comment 3 Alex Lowe 2024-10-10 12:59:25 UTC

Created attachment 174624 [details]
Pycharm not showing these backslashes

Comment 4 Alex Lowe 2024-10-10 13:00:22 UTC

Created attachment 174625 [details]
vscode not showing slashes

Comment 5 Alex Lowe 2024-10-10 13:05:24 UTC

Created attachment 174629 [details]
Visual Studio Code not showing backslashes

Comment 6 Alex Lowe 2024-10-10 13:34:29 UTC

(In reply to Waqar Ahmed from comment #1)
> I wonder if its the server's fault or our fault. If the server escapes
> markdown characters by putting backslashes, thats how they will appear...

I was initially working to create a report on the YAML language server, but I noticed that kate was also behaving this way with the vscode JSON language server. VSCode doesn't show this same behaviour though, either in JSON or in YAML.

I asked some coworkers to compare with their text editors and got the following:

- Emacs appears to behave mostly-correctly, but ignores the backslashes that are undoing the "markdownification" of bullet points and then treats those hyphens as bullet points
- PyCharm eats the newlines, but doesn't include the slashes (Incorrect because a double-newline in Markdown should be treated as a newline in the resulting formatted document)
- VSCode behaves what appears to be "most correctly" from a user perspective, as the contents field is correctly turned into a string (converting "\n" in the raw JSON to a newline character and unescaping "\\" to a single "\"), and then that string is treated as Markdown (including unescaping characters - see: https://www.markdownguide.org/basic-syntax/#characters-you-can-escape)

Looking further, the current protocol specification shows the "contents" field to be one of three types (https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_hover). In this case, it's a plain string, which is one of the two forms of the MarkedString type (https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#markedString). While this is a deprecated type, the relevance here is that the MarkedString is a union type either of a plain string which needs to be rendered in (presumably GitHub dialect) Markdown or an object that provides both the language and the value.

Comment 7 Alex Lowe 2024-10-10 13:46:45 UTC

While researching the last comment I found that someone had reported this in the YAML language server: https://github.com/redhat-developer/yaml-language-server/issues/837

I made a comment there because the research displayed in my last comment makes me think that it is behaving correctly, but I wanted to cross-link the bugs in both directions.

Comment 8 Waqar Ahmed 2024-10-11 06:46:58 UTC

Created attachment 174670 [details]
yaml server hover on master

This is how it looks like on latest master. I think this got fixed with the recent changes to hover code. Can you try the latest master? We have app-images available I think

Comment 9 Waqar Ahmed 2024-10-11 06:51:50 UTC

Please feel free to reopen if it isn't resolved