JSON5 support

lua/lspsettings/config.lua

@@ -1,5 +1,6 @@
 --- @class Config
 Config = {
+    json5 = true,
     paths = {
         vim.fs.joinpath(vim.fn.stdpath('config'), "lspsettings"),
         -- compatibility with `nlsp-settings` plugin
@@ -58,4 +59,20 @@ function Config:extend(opts)
     end
 end
 
+--- Returns supported settings files extensions
+--- @param prefix? string Add prefix to all extensions
+--- @return string[]
+function Config:extensions(prefix)
+    local extensions = { "json" }
+
+    if self.json5 then
+        extensions = { "json5", "jsonc", "json" }
+    end
+
+    if prefix then
+        return vim.fn.map(extensions, function(_, ext) return prefix .. ext end)
+    end
+    return extensions
+end
+
 return Config

lua/lspsettings/init.lua

@@ -67,7 +67,20 @@ M.open_settings_file = function(args)
     if not path then return end
 
     vim.fn.mkdir(path, "p")
-    vim.cmd.edit(vim.fs.joinpath(path, server_name .. ".json"))
+
+    local file_names = M.config:extensions(server_name .. ".")
+    local file_name = file_names[1]
+
+    -- Trying to find existing file
+    for _, fname in ipairs(file_names) do
+        local file_path = vim.fs.joinpath(path, fname)
+        if vim.fn.filereadable(file_path) == 1 then
+            file_name = fname
+            break
+        end
+    end
+
+    vim.cmd.edit(vim.fs.joinpath(path, file_name))
 end
 
 --- Setup to read from a settings file.
@@ -86,13 +99,13 @@ M.setup = function(opts)
 
     -- Bind callback to watch changes in configuration files
     vim.api.nvim_create_autocmd("BufWritePost", {
-        pattern = "*.json",
+        pattern = M.config:extensions("*."),
         callback = function(event_data)
             local full_path = event_data.match
             local relative_path = event_data.file
             local fname = vim.fs.basename(relative_path)
 
-            local server_name = fname:sub(1, -6)
+            local server_name = fname:gsub("%.json[c5]?$", "")
 
             -- Check that this `server_name` really exists
             if not vim.lsp.config[server_name] then

lua/lspsettings/json5.lua

@@ -0,0 +1,191 @@
+---@diagnostic disable: lowercase-global
+
+--- @param str string Stringified JSON5 data
+--- @param opts table<string,any> Options similar to `vim.json.decode`. Not used for now
+---@diagnostic disable-next-line: unused-local
+local function decode(str, opts)
+    local function tokenize(input)
+        local tokens = {}
+        local i = 1
+        local len = #input
+
+        local function skip_whitespace()
+            while i <= len do
+                local c = input:sub(i, i)
+                if c:match("[%s\n\r\t]") then
+                    i = i + 1
+                elseif c == "/" and input:sub(i + 1, i + 1) == "/" then
+                    i = i + 2
+                    while i <= len and input:sub(i, i) ~= "\n" do
+                        i = i + 1
+                    end
+                elseif c == "/" and input:sub(i + 1, i + 1) == "*" then
+                    i = i + 2
+                    while i <= len - 1 and not (input:sub(i, i + 1) == "*/") do
+                        i = i + 1
+                    end
+                    i = i + 2
+                else
+                    break
+                end
+            end
+        end
+
+        local function read_line(quote)
+            i = i + 1
+            local output = ""
+            while i <= len do
+                local c = input:sub(i, i)
+                if c == "\\" then
+                    local nextc = input:sub(i + 1, i + 1)
+                    if nextc == "n" then
+                        output = output .. "\n"
+                    elseif nextc == "t" then
+                        output = output .. "\t"
+                    elseif nextc == "r" then
+                        output = output .. "\r"
+                    elseif nextc == quote then
+                        output = output .. quote
+                    else
+                        output = output .. nextc
+                    end
+                    i = i + 2
+                elseif c == quote then
+                    i = i + 1
+                    break
+                else
+                    output = output .. c
+                    i = i + 1
+                end
+            end
+            return { type = "string", value = output }
+        end
+
+        local function read_number()
+            local start = i
+            while i <= len and input:sub(i, i):match("[%+%-%.%deE]") do
+                i = i + 1
+            end
+            local num_str = input:sub(start, i - 1)
+            if num_str == "NaN" then
+                return { type = "number", value = 0 / 0 }
+            elseif num_str == "Infinity" or num_str == "+Infinity" then
+                return { type = "number", value = math.huge }
+            elseif num_str == "-Infinity" then
+                return { type = "number", value = -math.huge }
+            else
+                return { type = "number", value = tonumber(num_str) }
+            end
+        end
+
+        local function read_identifier()
+            local start = i
+            while i <= len and input:sub(i, i):match("[%w%$_]") do
+                i = i + 1
+            end
+            local word = input:sub(start, i - 1)
+            if word == "true" then
+                return { type = "boolean", value = true }
+            elseif word == "false" then
+                return { type = "boolean", value = false }
+            elseif word == "null" then
+                return { type = "null", value = nil }
+            elseif word == "NaN" or word == "Infinity" or word == "-Infinity" then
+                i = start
+                return read_number()
+            else
+                return { type = "identifier", value = word }
+            end
+        end
+
+        while i <= len do
+            skip_whitespace()
+            local c = input:sub(i, i)
+            if c == "" then
+                break
+            elseif c == "{" or c == "}" or c == "[" or c == "]" or c == ":" or c == "," then
+                table.insert(tokens, { type = "symbol", value = c })
+                i = i + 1
+            elseif c == '"' or c == "'" then
+                table.insert(tokens, read_line(c))
+            elseif c:match("[%+%-%.%d]") then
+                table.insert(tokens, read_number())
+            elseif c:match("[%a$_]") then
+                table.insert(tokens, read_identifier())
+            else
+                error("Unexpected character: " .. c)
+            end
+        end
+
+        return tokens
+    end
+
+    local function parse(tokens)
+        local pos = 1
+
+        local function peek() return tokens[pos] end
+        local function next_tok()
+            local token = peek()
+            pos = pos + 1
+            return token
+        end
+
+        local function parse_value()
+            local token = peek()
+            if not token then error("Unexpected end") end
+            if token.type == "string" or token.type == "number" or token.type == "boolean" or token.type == "null" then
+                return next_tok().value
+            elseif token.value == "{" then
+                return parse_object()
+            elseif token.value == "[" then
+                return parse_array()
+            elseif token.type == "identifier" then
+                return next_tok().value
+            else
+                error("Unexpected token: " .. token.value)
+            end
+        end
+
+        function parse_array()
+            local result = {}
+            assert(next_tok().value == "[")
+            while peek() and peek().value ~= "]" do
+                table.insert(result, parse_value())
+                if peek().value == "," then next_tok() end
+            end
+            assert(next_tok().value == "]")
+            return result
+        end
+
+        function parse_object()
+            local result = {}
+            assert(next_tok().value == "{")
+            while peek() and peek().value ~= "}" do
+                local key_token = next_tok()
+                local key
+                if key_token.type == "string" or key_token.type == "identifier" then
+                    key = key_token.value
+                else
+                    error("Invalid object key")
+                end
+                assert(next_tok().value == ":")
+                local val = parse_value()
+                result[key] = val
+                if peek().value == "," then next_tok() end
+            end
+            assert(next_tok().value == "}")
+            return result
+        end
+
+        return parse_value()
+    end
+
+    local tokens = tokenize(str)
+
+    return parse(tokens)
+end
+
+
+return {
+    decode = decode,
+}

lua/lspsettings/loader.lua

@@ -36,7 +36,9 @@ local function set_key(key, value, target)
     local head = key:sub(1, index - 1)
     local tail = key:sub(index + 1)
 
-    target[head] = target[head] or {}
+    if type(target[head]) ~= "table" then
+        target[head] = {}
+    end
 
     set_key(tail, value, target[head])
 end
@@ -59,12 +61,18 @@ end
 --- @return string[]
 function JsonLoader:list_configured_servers()
     local result = {}
+    local extensions = self.config:extensions(".")
 
     for _, dir in ipairs(self.config.paths) do
         for name, type in vim.fs.dir(dir, { follow = true }) do
-            if type == "file" and name:sub(-5) == ".json" then
-                local server_name = name:sub(1, -6)
-                result[server_name] = true
+            if type == "file" then
+                for _, ext in ipairs(extensions) do
+                    if name:sub(-ext:len()) == ext then
+                        local server_name = name:sub(1, -(ext:len() + 1))
+                        result[server_name] = true
+                        break
+                    end
+                end
             end
         end
     end
@@ -78,10 +86,15 @@ end
 function JsonLoader:list_server_configs(server_name)
     local result = {}
     local paths = self.config.paths
-    for _, path in ipairs(paths) do
-        path = vim.fs.joinpath(path, server_name .. ".json")
-        if vim.fn.filereadable(path) == 1 then
-            table.insert(result, path)
+    local fnames = self.config:extensions(server_name .. ".")
+
+    for _, dir_path in ipairs(paths) do
+        for _, fname in ipairs(fnames) do
+            local file_path = vim.fs.joinpath(dir_path, fname)
+            if vim.fn.filereadable(file_path) == 1 then
+                table.insert(result, file_path)
+                break
+            end
         end
     end
 
@@ -92,18 +105,25 @@ end
 --- @param server_name string
 --- @return table
 function JsonLoader:load(server_name)
+    local decode = vim.json.decode
+    if self.config.json5 then
+        decode = require("lspsettings.json5").decode
+    end
+
     local settings = {}
 
     -- reading each config
     for _, path in ipairs(self:list_server_configs(server_name)) do
-        local jsoned = table.concat(vim.fn.readfile(path))
-        local opts = { luanil = { object = true, array = true } }
-        local success, data = pcall(vim.json.decode, jsoned, opts)
-
-        if success then
-            settings = vim.tbl_extend("force", settings, data)
-        else
-            vim.notify("Unable to load LSP settings at `" .. path .. "`: " .. vim.inspect(data), vim.log.levels.WARN)
+        local jsoned = table.concat(vim.fn.readfile(path), "\n")
+        if jsoned ~= "" then
+            local opts = { luanil = { object = true, array = true } }
+            local success, data = pcall(decode, jsoned, opts)
+
+            if success then
+                settings = vim.tbl_extend("force", settings, data)
+            else
+                vim.notify("Unable to load LSP settings at `" .. path .. "`: invalid JSON", vim.log.levels.WARN)
+            end
         end
     end
 

lua/lspsettings/schemas.lua

@@ -7,7 +7,7 @@ Schemas.__index = Schemas
 --- @return Schemas
 function Schemas:new()
     local o = {
-        schemas = {}
+        schemas = {},
     }
 
     setmetatable(o, self)
@@ -58,6 +58,7 @@ end
 
 --- Scans `./schemas` directory and forms list of available schemas.
 function Schemas:scan()
+    local extensions = { "json", "json5", "jsonc" }
     local init_lua_path = debug.getinfo(1).source:sub(2)
     local lspsettings_path = vim.fs.dirname(init_lua_path)
     local lua_path = vim.fs.dirname(lspsettings_path)
@@ -73,9 +74,10 @@ function Schemas:scan()
         if type == "file" and name:sub(-5) == ".json" then
             local server_name = name:sub(1, -6)
             local file_path = vim.fs.abspath(vim.fs.joinpath(schemas_path, name))
+            local matches = vim.fn.map(extensions, function(_, ext) return server_name .. "." .. ext end)
 
             self.schemas[server_name] = {
-                fileMatch = { name },
+                fileMatch = matches,
                 url = "/" .. file_path,
             }
         end
@@ -84,11 +86,13 @@ end
 
 --- Applies given schemas list to `jsonls`
 function Schemas:apply()
+    local config = require("lspsettings").config
+    local extensions = config:extensions()
+
     vim.lsp.config('jsonls', {
+        filetypes = extensions,
         settings = {
-            json = {
-                schemas = vim.tbl_values(self.schemas),
-            },
+            json = { schemas = vim.tbl_values(self.schemas) },
         },
     })
 end

lua/lspsettings/types.lua

@@ -1,4 +1,5 @@
 ---@class lspsettings.types.config
+---@field json5 boolean? default true. Experimental
 ---@field paths string|string[]?
 ---@field on_settings fun(server_name: string, settings: table): nil?