Add LuaCheck and GitHub workflow (#32)

Sprinting didn't work when a player has fast but it was turned off. With
fly, fast was always enabled and sprinting didn't make them any faster,
now it does.

.github/workflows/build.yml

@@ -0,0 +1,11 @@
+on: [push, pull_request]
+name: build
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: lint
+        uses: Roang-zero1/factorio-mod-luacheck@master
+        with:
+          luacheckrc_url: ""

.luacheckrc

@@ -0,0 +1,19 @@
+allow_defined_top = true
+unused_args = false
+max_line_length = false
+
+read_globals = {
+    string = {fields = {"split", "trim"}},
+    table = {fields = {"copy", "getn"}},
+
+    "player_monoids",
+    "playerphysics",
+    "hb",
+    "vector",
+    "hunger_ng",
+}
+
+globals = {
+    "minetest",
+    "hbhunger"
+}

init.lua

@@ -130,8 +130,8 @@ local function is_walkable(ground)
 end
 
 local function create_particles(player, name, ground)
-  local def = minetest.registered_nodes[ground.name]
+  local def = minetest.registered_nodes[ground.name] or {}
-  local tile = def.tiles[1] or def.inventory_image
+  local tile = def.tiles and def.tiles[1] or def.inventory_image
   if type(tile) == "table" then
     tile = tile.name
   end
@@ -182,17 +182,16 @@ end)
 
 local function sprint_step(player, dtime)
   local name = player:get_player_name()
+  local fast = minetest.get_player_privs(name).fast
 
-  if minetest.get_player_privs(name).fast then
+  if not fast then
-    return
-  end
-
     if stamina then
       stamina_timer[name] = (stamina_timer[name] or 0) + dtime
     end
     if breath then
       breath_timer[name] = (breath_timer[name] or 0) + dtime
     end
+  end
 
   local ctrl = player:get_player_control()
   local key_press
@@ -204,7 +203,7 @@ local function sprint_step(player, dtime)
 
   if not key_press then
     stop_sprint(player)
-    if stamina and stamina_timer[name] >= replenish then
+    if stamina and not fast and stamina_timer[name] >= replenish then
       replenish_stamina(player)
       stamina_timer[name] = 0
     end
@@ -235,15 +234,15 @@ local function sprint_step(player, dtime)
     hunger = hunger_ng.get_hunger_information(name).hunger.exact
   end
 
-  if player_stamina > 0 and hunger > starve_limit and ground then
+  if (player_stamina > 0 and hunger > starve_limit and ground) or fast then
     start_sprint(player)
-    if stamina then drain_stamina(player) end
+    if stamina and not fast then drain_stamina(player) end
-    if starve then drain_hunger(player, name) end
+    if starve and not fast then drain_hunger(player, name) end
-    if breath and breath_timer[name] >= 2 then
+    if breath and not fast and breath_timer[name] >= 2 then
       drain_breath(player)
       breath_timer[name] = 0
     end
-    if particles then
+    if particles and ground then
       create_particles(player, name, ground)
     end
   else