Add Continuous Integration and LuaCheck (#71)

All warnings have been fixed as well.

.github/workflows/build.yml

@@ -0,0 +1,11 @@
+on: [push, pull_request]
+name: build
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: lint
+        uses: Roang-zero1/factorio-mod-luacheck@master
+        with:
+          luacheckrc_url: ""

.luacheckrc

@@ -0,0 +1,13 @@
+unused_args = false
+allow_defined_top = true
+max_line_length = 999
+
+globals = {
+    "minetest", "unified_inventory", "core",
+    "player_api", "clothing", "armor", "sfinv",
+}
+
+read_globals = {
+    string = {fields = {"split", "trim"}},
+    table = {fields = {"copy", "getn"}},
+}

formspecs.lua

@@ -57,7 +57,7 @@ function skins.get_skin_selection_formspec(player, context, perplayer_formspec)
 	local yspc = 2
 	local skinwidth = 1
 	local skinheight = 2
-	local xscale = 1
+	local xscale = 1 -- luacheck: ignore
 	local btn_y = 8.15
 	local drop_y = 8
 	local btn_width = 1

skinlist.lua

@@ -1,7 +1,7 @@
 local skins_dir_list = minetest.get_dir_list(skins.modpath.."/textures")
 
 for _, fn in pairs(skins_dir_list) do
-	local name, sort_id, assignment, is_preview, playername
+	local name, sort_id, is_preview, playername
 	local nameparts = string.gsub(fn, "[.]", "_"):split("_")
 
 	-- check allowed prefix and file extension