fix syntax errors, logic errors, add logging to find errors, test that it works

main.lua

@@ -1,7 +1,13 @@
+local log = require "lib.log"
 local tilesheet = require "lib.tilesheet"
 local utf8 = require "utf8"
 local utility = require "lib.utility"
 
+log{
+  keypressed = false,
+  textinput = false,
+}
+
 local window_width, window_height = love.graphics.getDimensions()
 
 local tiles, tiles_json, tile_image, tile_usage
@@ -13,7 +19,7 @@ local current_x, current_y = 1, 1
 local flag_new_file -- this automatically chooses a JSON file location for new files
 
 local prompts = {
-  start_new = "Drag and drop an image or JSON file to name tiles."
+  start_new = "Drag and drop an image or JSON file to name tiles.",
   tile_size = "Enter the tile_size for this tilesheet:",
   enter_name = "Enter the name for this tile (leave empty to skip):",
 }
@@ -40,9 +46,9 @@ end
 
 local next_unused_tile = function(tiles_json, tile_image, tile_usage)
   local tile_size = tiles_json.tile_size
-  for x = current_x, #tile_usage do
-    for y = current_y, #tile_usage[1] do
-      if not tile_usage[x][y] then
+  for x = 1, #tile_usage do
+    for y = 1, #tile_usage[1] do
+      if not (tile_usage[x][y]) then
         current_x = x
         current_y = y
         current_quad = love.graphics.newQuad( (x - 1) * tile_size, (y - 1) * tile_size, tile_size, tile_size, tile_image )
@@ -52,6 +58,15 @@ local next_unused_tile = function(tiles_json, tile_image, tile_usage)
   end
 end
 
+local save_tileset = function()
+  if not (tiles_json) then return end
+  if flag_new_file then
+    utility.save_data(tiles_json, tiles_json.image_path .. ".json")
+  else
+    utility.save_data(tiles_json)
+  end
+end
+
 
 
 function love.load()
@@ -68,18 +83,21 @@ function love.draw()
 end
 
 function love.textinput(character)
+  log("textinput", "textinput", character)
   current_text = current_text .. character
 end
 
 function love.keypressed(key)
+  log("keypressed", "keypressed", key)
   if key == "escape" then
+    save_tileset()
     love.event.quit()
   elseif key == "backspace" then
     local byteoffset = utf8.offset(current_text, -1)
     if byteoffset then
       current_text = current_text:sub(1, byteoffset - 1)
     end
-  elseif key == "enter" then
+  elseif key == "return" then
     -- end of a textinput; what to do depends on what was being asked
     if current_prompt == prompts.tile_size then
       tiles_json.tile_size = tonumber(current_text)
@@ -95,19 +113,18 @@ function love.keypressed(key)
       tile_usage[current_x][current_y] = true
       current_text = ""
       if not (next_unused_tile(tiles_json, tile_image, tile_usage)) then
-        if flag_new_file then
-          utility.save_data(tiles_json, tiles_json.image_path .. ".json")
-        else
-          utility.save_data(tiles_json)
-        end
+        save_tileset()
         current_prompt = prompts.start_new
       end
     end
   end
 end
 
-function love.filedropped(file_path)
-  if file_path:sub(-5) == ".json" then
+function love.filedropped(dropped_file)
+  local file_path = dropped_file:getFilename()
+  local file_extension = file_path:match("%.%w+$")
+
+  if file_extension == ".json" then
     tiles_json = utility.load_data(file_path)
     flag_new_file = false
     tiles, tile_image = tilesheet(tiles_json)
@@ -118,6 +135,7 @@ function love.filedropped(file_path)
   else
     tiles_json = {
       image_path = file_path,
+      tiles = {},
       -- tile_size is not defined yet
     }
     flag_new_file = true