Setting up "textDocument/publishDiagnostics" handler broke between nvim 0.9.5 and nvim 0.10.0 for jsonls

[michaelrommel]

Hi,
I had a fully working setup, that broke when I upgraded nvim to 0.10.3, but narrrowing it down, already 0.10.0 broke it. I used to override the default handler in order to ignore some diagnostic errors, e.g. comments in json5, but jsonls did not understand json5.
I have reduced my config to just those lines (and the lazy plugin manager that loads this file):

return {
	"williamboman/mason-lspconfig.nvim",
	lazy = false,
	ft = { "json", "json5" },
	dependencies = {
		"williamboman/mason.nvim",
		"neovim/nvim-lspconfig",
	},
	config = function()
		require('mason').setup({
		})
		require('mason-lspconfig').setup({
			ensure_installed = {
				"jsonls",
			},
		})
		require("mason-lspconfig").setup_handlers {
			-- The first entry (without a key) will be the default handler
			function(server_name)
				require("lspconfig")[server_name].setup({
				})
			end,
			-- Next, you can provide a dedicated handler for specific servers.
			["jsonls"] = function()
				print("installing jsonls handler")
				require("lspconfig").jsonls.setup({
					filetypes = { "json", "jsonc", "json5" },
					handlers = {
						["textDocument/publishDiagnostics"] = function(err, result, ctx, config)
							print("jsonls diagnostics")
							vim.lsp.diagnostic.on_publish_diagnostics(err, result, ctx, config)
						end,
					},
				})
			end,
		}
	end
}

If I open a json5 document, the LSP attaches, the message "installing jsonls handler" is printed, but the "jsonls diagnostics" line is never printed, the whole function is completly ignored.

I have now search 4h including neovim source code, mason, nvim-lspconfig and now I am at a loss, why this would not work anymore. I read that vim.lsp.handlers is deprecated in v0.11 onwards, but I could not find any clue as to how users should migrate their config.

Is there s.b. that understands, why the handler is not invoked? Thanks in advance!!

[michaelrommel]

Interestingly enough, with jedi_language_server the same methodology works and I get the print statement:

return {
	"williamboman/mason-lspconfig.nvim",
	lazy = false,
	ft = { "python", "json", "json5" },
	dependencies = {
		"williamboman/mason.nvim",
		"neovim/nvim-lspconfig",
	},
	config = function()
		require('mason').setup({
		})
		require('mason-lspconfig').setup({
			ensure_installed = {
				"jsonls", "jedi_language_server"
			},
		})
		require("mason-lspconfig").setup_handlers {
			-- The first entry (without a key) will be the default handler
			function(server_name)
				require("lspconfig")[server_name].setup({
				})
			end,
			-- Next, you can provide a dedicated handler for specific servers.
			["jsonls"] = function()
				print("installing jsonls handler")
				require("lspconfig").jsonls.setup({
					filetypes = { "json", "jsonc", "json5" },
					handlers = {
						["textDocument/publishDiagnostics"] = function(err, result, ctx, config)
							print("jsonls diagnostics")
							vim.lsp.diagnostic.on_publish_diagnostics(err, result, ctx, config)
						end,
					},
				})
			end,
			["jedi_language_server"] = function()
				print("installing python handler")
				require("lspconfig").jedi_language_server.setup({
					filetypes = { "python" },
					handlers = {
						["textDocument/publishDiagnostics"] = function(err, result, ctx, config)
							print("python diagnostics")
							vim.lsp.diagnostic.on_publish_diagnostics(err, result, ctx, config)
						end,
					},
				})
			end,
		}
	end
}

Anyone understands, what the difference between jsonls and jedi is and why it stopped working when neovim was upgraded to 0.10.0?

[michaelrommel]

It seems that jsonls sends this as a response to a textDocument/diagnostic request from the client:

[DEBUG][2025-01-21 13:26:43] .../vim/lsp/rpc.lua:408    "rpc.receive"   {  id = 35,  jsonrpc = "2.0",  result = {    items = { {        code = 521,        message = "Comments are not permitted in JSON.",        range = {          ["end"] = {            character = 15,            line = 0          },          start = {            character = 0,            line = 0          }        },        severity = 1      } },    kind = "full"  }}

whereas jedi send this on its own after a textDocument/didChange message sent to it:

[DEBUG][2025-01-21 13:30:32] .../vim/lsp/rpc.lua:408    "rpc.receive"   {  jsonrpc = "2.0",  method = "textDocument/publishDiagnostics",  params = {    diagnostics = { {        message = "SyntaxError: invalid syntax (test.py, line 3)",        range = {          ["end"] = {            character = 9,            line = 2          },          start = {            character = 8,            line = 2          }        },        severity = 1,        source = "compile"      } },    uri = "file:///home/rommel/.config/demo/test.py"  }}

I have no idea, why the different language servers behave completely differently and what is the "correct" behaviour.

[michaelrommel]

So the neovim 0.9.5 version does send to the same jsonls languageserver different messages, namely the ones that are also sent to the python one.

[DEBUG][2025-01-21 14:11:47] .../vim/lsp/rpc.lua:387    "rpc.receive"   {  jsonrpc = "2.0",  method = "textDocument/publishDiagnostics",  params = {    diagnostics = { {        code = 521,        message = "Comments are not permitted in JSON.",        range = {          ["end"] = {            character = 15,            line = 0          },          start = {            character = 0,            line = 0          }        },        severity = 1      } },    uri = "file:///home/rommel/.config/demo/test.json"  }} 

So I have no idea, where I should look info resolving this. It is the exact same configuration that I posted in my second message, that works with exactly the same language server under neovim 0.9.5 and no longer works with 0.10.3. But 0.10.3 sends the same messages to python as 0.9.5.

I guess no one reads this discussion or has any clue, where to look. Guess I can close the discussion later this week as unresolved.

[michaelrommel]

Answering myself here: you can override the [textDocument/diagnostic] handler and modify the result.items table.