fix: respect language settings of imported files

cspell only respects the language of the main config, thus making it
impossible to add new languages exclusively by importing them. This
commit appends all the languages found in imported files to the main
config automatically.

Author: KotarouX

lua/cspell/helpers.lua

@@ -79,11 +79,29 @@ M.create_merged_cspell_json = function(params, cspell_config_mapping)
         return CONFIG_INFO_BY_PATH[merged_config_path]
     end
 
+    local cspell_json = {
+        version = "0.2",
+        language = "en",
+        words = {},
+        flagWords = {},
+        import = cspell_config_paths,
+    }
+
     for _, cspell_config_path in pairs(cspell_config_mapping) do
         local path_exists = cspell_config_path ~= nil
             and cspell_config_path ~= ""
             and Path:new(cspell_config_path):exists()
         if path_exists then
+            pcall(function()
+                local cspell_config = vim.json.decode(Path:new(cspell_config_path):read())
+                if
+                    cspell_config.language ~= nil
+                    and type(cspell_config.language) == "string"
+                    and cspell_config.language ~= ''
+                then
+                    cspell_json.language = cspell_json.language .. "," .. cspell_config.language
+                end
+            end)
             table.insert(cspell_config_paths, cspell_config_path)
         else
             local debug_message = M.format(
@@ -94,14 +112,6 @@ M.create_merged_cspell_json = function(params, cspell_config_mapping)
         end
     end
 
-    local cspell_json = {
-        version = "0.2",
-        language = "en",
-        words = {},
-        flagWords = {},
-        import = cspell_config_paths,
-    }
-
     local existing_config = M.get_cspell_config(params, merged_config_path)
 
     if existing_config ~= nil then
@@ -219,8 +229,8 @@ M.generate_cspell_config_path = function(params, directory)
     if not vim.tbl_contains(CSPELL_CONFIG_FILES, config_file_preferred_name) then
         vim.notify(
             "Invalid config_file_preferred_name for cspell json file: "
-                .. config_file_preferred_name
-                .. '. The name "cspell.json" will be used instead',
+            .. config_file_preferred_name
+            .. '. The name "cspell.json" will be used instead',
             vim.log.levels.WARN,
             { title = "cspell.nvim" }
         )