feat: allowing handlers to be passed in via setup function

lua/mason-null-ls/init.lua

@@ -15,43 +15,18 @@ local default_setup = function(source, types)
 	end
 end
 
----@param config MasonNullLsSettings | nil
-function M.setup(config)
-	local settings = require('mason-null-ls.settings')
-
-	if config then
-		settings.set(config)
-	end
-
-	-- NOTE: this is left here for future porting in case needed
-	-- local ok, err = pcall(function()
-	--     require "mason-lspconfig.lspconfig_hook"()
-	--     require "mason-lspconfig.server_config_extensions"()
-	-- end)
-	-- if not ok then
-	--     log.error("Failed to set up lspconfig integration.", err)
-	-- end
-
-	if #settings.current.ensure_installed > 0 then
-		require('mason-null-ls.ensure_installed')()
-	end
-
-	if settings.current.automatic_installation then
-		require('mason-null-ls.automatic_installation')()
-	end
-
-	require('mason-null-ls.api.command')
-end
-
----@param handlers table<string, fun(source_name: string, methods: string[])>
-function M.setup_handlers(handlers)
+---@param handlers table<string, fun(source_name: string, methods: string[])> | nil
+---@return nil
+local function setup_handlers(handlers)
 	handlers = handlers or {}
+
 	local Optional = require('mason-core.optional')
 	local source_mappings = require('mason-null-ls.mappings.source')
 	local registry = require('mason-registry')
 	local notify = require('mason-core.notify')
 
 	local default_handler = Optional.of_nilable(handlers[1]):or_(_.always(Optional.of_nilable(default_setup)))
+
 	_.each(function(handler)
 		if type(handler) == 'string' and not source_mappings.getPackageFromNullLs(handler) then
 			notify(
@@ -68,6 +43,7 @@ function M.setup_handlers(handlers)
 
 	local function call_handler(source_name)
 		log.fmt_trace('Checking handler for %s', source_name)
+
 		Optional.of_nilable(handlers[source_name]):or_(_.always(default_handler)):if_present(function(handler)
 			log.fmt_trace('Calling handler for %s', source_name)
 
@@ -81,6 +57,7 @@ function M.setup_handlers(handlers)
 			end, { 'diagnostics', 'formatting', 'code_actions', 'completion', 'hover' })
 
 			local ok, err = pcall(handler, source_name, types)
+
 			if not ok then
 				vim.notify(err, vim.log.levels.ERROR)
 			end
@@ -97,6 +74,45 @@ function M.setup_handlers(handlers)
 	)
 end
 
+---@param config MasonNullLsSettings | nil
+function M.setup(config)
+	local settings = require('mason-null-ls.settings')
+
+	if config then
+		settings.set(config)
+	end
+
+	-- NOTE: this is left here for future porting in case needed
+	-- local ok, err = pcall(function()
+	--     require "mason-lspconfig.lspconfig_hook"()
+	--     require "mason-lspconfig.server_config_extensions"()
+	-- end)
+	-- if not ok then
+	--     log.error("Failed to set up lspconfig integration.", err)
+	-- end
+
+	if #settings.current.ensure_installed > 0 then
+		require('mason-null-ls.ensure_installed')()
+	end
+
+	if settings.current.automatic_installation then
+		require('mason-null-ls.automatic_installation')()
+	end
+
+	if settings.current.handlers then
+		setup_handlers(settings.current.handlers)
+	end
+
+	require('mason-null-ls.api.command')
+end
+
+---@param handlers table<string, fun(source_name: string, methods: string[])> | nil
+---@deprecated
+---@return nil
+function M.setup_handlers(handlers)
+	return setup_handlers(handlers)
+end
+
 ---@return string[]
 function M.get_installed_sources()
 	local Optional = require('mason-core.optional')

lua/mason-null-ls/settings.lua

@@ -1,11 +1,14 @@
 local M = {}
 
 ---@class MasonNullLsSettings
+---@field handlers table | nil
+---@field automatic_setup boolean | table
+---@field ensure_installed table
+---@field automatic_installation boolean | table
 local DEFAULT_SETTINGS = {
 	-- A list of sources to automatically install if they're not already installed. Example: { "stylua" }
 	-- This setting has no relation with the `automatic_installation` setting.
 	ensure_installed = {},
-
 	-- NOTE: this is left here for future porting in case needed
 	-- Whether sources that are set up (via null-ls) should be automatically installed if they're not already installed.
 	-- This setting has no relation with the `ensure_installed` setting.
@@ -15,7 +18,6 @@ local DEFAULT_SETTINGS = {
 	--   - { exclude: string[] }: All servers set up via mason-null-ls, except the ones provided in the list, are automatically installed.
 	--       Example: automatic_installation = { exclude = { "stylua", "eslint", } }
 	automatic_installation = false,
-
 	-- Whether sources that are installed in mason should be automatically set up in null-ls.
 	-- Removes the need to set up null-ls manually.
 	-- Can either be:
@@ -24,6 +26,7 @@ local DEFAULT_SETTINGS = {
 	-- 	- { types = { SOURCE_NAME = {TYPES} } }. Allows overriding default configuration.
 	-- 	Ex: { types = { eslint_d = {'formatting'} } }
 	automatic_setup = false,
+	handlers = nil,
 }
 
 M._DEFAULT_SETTINGS = DEFAULT_SETTINGS
@@ -40,6 +43,7 @@ function M.set(opts)
 		ensure_installed = { M.current.ensure_installed, 'table', true },
 		automatic_installation = { M.current.automatic_installation, { 'boolean', 'table' }, true },
 		automatic_setup = { M.current.automatic_setup, { 'boolean', 'table' }, true },
+		handlers = { M.current.handlers, { 'table' }, true },
 	})
 end