compare ts_ls and volar capabilities at runtime

compare_lsp_runtime.lua

-- Script to compare ts_ls and volar capabilities at runtime
-- This will definitively show what capabilities conflict

local function get_client_caps(client_name)
	-- Get list of all active LSP clients
	local clients = vim.lsp.get_clients and vim.lsp.get_clients() or vim.lsp.get_active_clients()
	for _, client in ipairs(clients) do
		if client.name == client_name then
			local caps = {}
			for capability, value in pairs(client.server_capabilities) do
				if value ~= false and value ~= nil then
					caps[capability] = true
				end
			end
			return caps
		end
	end
	return {}
end

local function compare_capabilities()
	-- Get capabilities from both servers
	local ts_caps = get_client_caps("ts_ls")
	local volar_caps = get_client_caps("volar")

	if next(ts_caps) == nil then
		print("Error: ts_ls not found. Make sure a .vue or .ts file is open")
		return
	end

	if next(volar_caps) == nil then
		print("Error: volar not found. Make sure a .vue file is open")
		return
	end

	-- Find overlapping capabilities
	local conflicts = {}
	local volar_only = {}
	local ts_only = {}

	for cap, _ in pairs(volar_caps) do
		if ts_caps[cap] then
			table.insert(conflicts, cap)
		else
			table.insert(volar_only, cap)
		end
	end

	for cap, _ in pairs(ts_caps) do
		if not volar_caps[cap] then
			table.insert(ts_only, cap)
		end
	end

	-- Sort for consistent output
	table.sort(conflicts)
	table.sort(volar_only)
	table.sort(ts_only)

	-- Generate output
	local output = {}

	table.insert(output, "=== LSP Capability Comparison ===")
	table.insert(output, "Date: " .. os.date())
	table.insert(output, "")

	table.insert(output, "CONFLICTING CAPABILITIES (both servers provide):")
	table.insert(output, "-" .. string.rep("-", 50))
	for _, cap in ipairs(conflicts) do
		table.insert(output, "  " .. cap)
	end

	table.insert(output, "")
	table.insert(output, "VOLAR-ONLY CAPABILITIES (Vue-specific):")
	table.insert(output, "-" .. string.rep("-", 50))
	for _, cap in ipairs(volar_only) do
		table.insert(output, "  " .. cap)
	end

	table.insert(output, "")
	table.insert(output, "TS_LS-ONLY CAPABILITIES:")
	table.insert(output, "-" .. string.rep("-", 50))
	for _, cap in ipairs(ts_only) do
		table.insert(output, "  " .. cap)
	end

	-- Generate Neovim config
	table.insert(output, "")
	table.insert(output, "=== RECOMMENDED CONFIG ===")
	table.insert(output, "-" .. string.rep("-", 50))
	table.insert(output, "-- Option 1: Disable conflicts in Volar")
	table.insert(output, "on_attach = function(client, _)")
	table.insert(output, "  if client.name == 'volar' then")
	table.insert(output, "    local disable = {")
	for _, cap in ipairs(conflicts) do
		table.insert(output, "      '" .. cap .. "',")
	end
	table.insert(output, "    }")
	table.insert(output, "    for _, cap in ipairs(disable) do")
	table.insert(output, "      client.server_capabilities[cap] = false")
	table.insert(output, "    end")
	table.insert(output, "  end")
	table.insert(output, "end")

	table.insert(output, "")
	table.insert(output, "-- Option 2: Keep only Vue-specific features")
	table.insert(output, "on_attach = function(client, _)")
	table.insert(output, "  if client.name == 'volar' then")
	table.insert(output, "    local vue_only = {")
	for _, cap in ipairs(volar_only) do
		table.insert(output, "      " .. cap .. " = true,")
	end
	-- Add essential capabilities
	table.insert(output, "      textDocumentSync = true,")
	table.insert(output, "      workspace = true,")
	table.insert(output, "    }")
	table.insert(output, "    for capability, _ in pairs(client.server_capabilities) do")
	table.insert(output, "      if not vue_only[capability] then")
	table.insert(output, "        client.server_capabilities[capability] = false")
	table.insert(output, "      end")
	table.insert(output, "    end")
	table.insert(output, "  end")
	table.insert(output, "end")

	-- Write to file
	local file = io.open("/tmp/lsp_comparison_results.txt", "w")
	if file then
		file:write(table.concat(output, "\n"))
		file:close()
		print("Comparison results written to: /tmp/lsp_comparison_results.txt")

		-- Also print summary
		print("\n=== SUMMARY ===")
		print("Conflicting capabilities: " .. #conflicts)
		print("Volar-only capabilities: " .. #volar_only)
		print("ts_ls-only capabilities: " .. #ts_only)
		print("\nRun :e /tmp/lsp_comparison_results.txt to see full results")
	else
		-- Print to console if can't write file
		print(table.concat(output, "\n"))
	end
end

-- Usage:
-- 1. Comment out the on_attach function in your Volar config (lspconfig.lua)
-- 2. Restart Neovim completely (:qa and reopen)
-- 3. Open a .vue file (both ts_ls and volar will start)
-- 4. Run :luafile /tmp/compare_lsp_runtime.lua
-- The comparison will run automatically and save results to /tmp/lsp_comparison_results.txt

-- Run the comparison automatically when this file is sourced
compare_capabilities()