more tests, fixed theme validation

modules/Theme.lua

@@ -663,4 +663,271 @@ end
 -- Export both Theme and ThemeManager
 Theme.Manager = ThemeManager
 
+---Validate a theme definition for structural correctness (non-aggressive)
+---@param theme table? The theme to validate
+---@param options table? Optional validation options {strict: boolean}
+---@return boolean valid, table errors List of validation errors
+function Theme.validateTheme(theme, options)
+  local errors = {}
+  options = options or {}
+
+  -- Basic structure validation
+  if theme == nil then
+    table.insert(errors, "Theme is nil")
+    return false, errors
+  end
+
+  if type(theme) ~= "table" then
+    table.insert(errors, "Theme must be a table")
+    return false, errors
+  end
+
+  -- Name validation (only required field)
+  if not theme.name then
+    table.insert(errors, "Theme must have a 'name' field")
+  elseif type(theme.name) ~= "string" then
+    table.insert(errors, "Theme 'name' must be a string")
+  elseif theme.name == "" then
+    table.insert(errors, "Theme 'name' cannot be empty")
+  end
+
+  -- Colors validation (optional, but if present must be valid)
+  if theme.colors ~= nil then
+    if type(theme.colors) ~= "table" then
+      table.insert(errors, "Theme 'colors' must be a table")
+    else
+      for colorName, colorValue in pairs(theme.colors) do
+        if type(colorName) ~= "string" then
+          table.insert(errors, "Color name must be a string, got " .. type(colorName))
+        else
+          -- Accept Color objects, hex strings, or named colors
+          local colorType = type(colorValue)
+          if colorType == "table" then
+            -- Assume it's a Color object if it has r,g,b fields
+            if not (colorValue.r and colorValue.g and colorValue.b) then
+              table.insert(errors, "Color '" .. colorName .. "' is not a valid Color object")
+            end
+          elseif colorType == "string" then
+            -- Validate color string
+            local isValid, err = Color.validateColor(colorValue)
+            if not isValid then
+              table.insert(errors, "Color '" .. colorName .. "': " .. err)
+            end
+          else
+            table.insert(errors, "Color '" .. colorName .. "' must be a Color object or string")
+          end
+        end
+      end
+    end
+  end
+
+  -- Fonts validation (optional)
+  if theme.fonts ~= nil then
+    if type(theme.fonts) ~= "table" then
+      table.insert(errors, "Theme 'fonts' must be a table")
+    else
+      for fontName, fontPath in pairs(theme.fonts) do
+        if type(fontName) ~= "string" then
+          table.insert(errors, "Font name must be a string, got " .. type(fontName))
+        elseif type(fontPath) ~= "string" then
+          table.insert(errors, "Font '" .. fontName .. "' path must be a string")
+        end
+      end
+    end
+  end
+
+  -- Components validation (optional)
+  if theme.components ~= nil then
+    if type(theme.components) ~= "table" then
+      table.insert(errors, "Theme 'components' must be a table")
+    else
+      for componentName, component in pairs(theme.components) do
+        if type(component) == "table" then
+          -- Validate atlas if present
+          if component.atlas ~= nil and type(component.atlas) ~= "string" then
+            table.insert(errors, "Component '" .. componentName .. "' atlas must be a string")
+          end
+
+          -- Validate insets if present
+          if component.insets ~= nil then
+            if type(component.insets) ~= "table" then
+              table.insert(errors, "Component '" .. componentName .. "' insets must be a table")
+            else
+              -- If insets are provided, all 4 sides must be present
+              for _, side in ipairs({ "left", "top", "right", "bottom" }) do
+                if component.insets[side] == nil then
+                  table.insert(errors, "Component '" .. componentName .. "' insets must have '" .. side .. "' field")
+                elseif type(component.insets[side]) ~= "number" then
+                  table.insert(errors, "Component '" .. componentName .. "' insets." .. side .. " must be a number")
+                elseif component.insets[side] < 0 then
+                  table.insert(errors, "Component '" .. componentName .. "' insets." .. side .. " must be non-negative")
+                end
+              end
+            end
+          end
+
+          -- Validate states if present
+          if component.states ~= nil then
+            if type(component.states) ~= "table" then
+              table.insert(errors, "Component '" .. componentName .. "' states must be a table")
+            else
+              for stateName, stateComponent in pairs(component.states) do
+                if type(stateComponent) ~= "table" then
+                  table.insert(errors, "Component '" .. componentName .. "' state '" .. stateName .. "' must be a table")
+                end
+              end
+            end
+          end
+
+          -- Validate scaleCorners if present
+          if component.scaleCorners ~= nil then
+            if type(component.scaleCorners) ~= "number" then
+              table.insert(errors, "Component '" .. componentName .. "' scaleCorners must be a number")
+            elseif component.scaleCorners <= 0 then
+              table.insert(errors, "Component '" .. componentName .. "' scaleCorners must be positive")
+            end
+          end
+
+          -- Validate scalingAlgorithm if present
+          if component.scalingAlgorithm ~= nil then
+            if type(component.scalingAlgorithm) ~= "string" then
+              table.insert(errors, "Component '" .. componentName .. "' scalingAlgorithm must be a string")
+            elseif component.scalingAlgorithm ~= "nearest" and component.scalingAlgorithm ~= "bilinear" then
+              table.insert(errors, "Component '" .. componentName .. "' scalingAlgorithm must be 'nearest' or 'bilinear'")
+            end
+          end
+        end
+      end
+    end
+  end
+
+  -- contentAutoSizingMultiplier validation (optional)
+  if theme.contentAutoSizingMultiplier ~= nil then
+    if type(theme.contentAutoSizingMultiplier) ~= "table" then
+      table.insert(errors, "Theme 'contentAutoSizingMultiplier' must be a table")
+    else
+      if theme.contentAutoSizingMultiplier.width ~= nil then
+        if type(theme.contentAutoSizingMultiplier.width) ~= "number" then
+          table.insert(errors, "contentAutoSizingMultiplier.width must be a number")
+        elseif theme.contentAutoSizingMultiplier.width <= 0 then
+          table.insert(errors, "contentAutoSizingMultiplier.width must be positive")
+        end
+      end
+      if theme.contentAutoSizingMultiplier.height ~= nil then
+        if type(theme.contentAutoSizingMultiplier.height) ~= "number" then
+          table.insert(errors, "contentAutoSizingMultiplier.height must be a number")
+        elseif theme.contentAutoSizingMultiplier.height <= 0 then
+          table.insert(errors, "contentAutoSizingMultiplier.height must be positive")
+        end
+      end
+    end
+  end
+
+  -- Global atlas validation (optional)
+  if theme.atlas ~= nil then
+    if type(theme.atlas) ~= "string" then
+      table.insert(errors, "Theme 'atlas' must be a string")
+    end
+  end
+
+  -- Strict mode: warn about unknown fields
+  if options.strict then
+    local knownFields = {
+      name = true,
+      atlas = true,
+      components = true,
+      colors = true,
+      fonts = true,
+      contentAutoSizingMultiplier = true,
+    }
+    for field in pairs(theme) do
+      if not knownFields[field] then
+        table.insert(errors, "Unknown field '" .. field .. "' in theme")
+      end
+    end
+  end
+
+  return #errors == 0, errors
+end
+
+---Sanitize a theme definition by removing invalid values and providing defaults
+---@param theme table? The theme to sanitize
+---@return table sanitized The sanitized theme
+function Theme.sanitizeTheme(theme)
+  local sanitized = {}
+
+  -- Handle nil theme
+  if theme == nil then
+    return { name = "Invalid Theme" }
+  end
+
+  -- Handle non-table theme
+  if type(theme) ~= "table" then
+    return { name = "Invalid Theme" }
+  end
+
+  -- Sanitize name
+  if type(theme.name) == "string" and theme.name ~= "" then
+    sanitized.name = theme.name
+  else
+    sanitized.name = "Unnamed Theme"
+  end
+
+  -- Sanitize colors
+  if type(theme.colors) == "table" then
+    sanitized.colors = {}
+    for colorName, colorValue in pairs(theme.colors) do
+      if type(colorName) == "string" then
+        local colorType = type(colorValue)
+        if colorType == "table" and colorValue.r and colorValue.g and colorValue.b then
+          -- Valid Color object
+          sanitized.colors[colorName] = colorValue
+        elseif colorType == "string" then
+          -- Try to validate color string
+          local isValid = Color.validateColor(colorValue)
+          if isValid then
+            sanitized.colors[colorName] = colorValue
+          else
+            -- Provide fallback color
+            sanitized.colors[colorName] = Color.new(0, 0, 0, 1)
+          end
+        end
+      end
+    end
+  end
+
+  -- Sanitize fonts
+  if type(theme.fonts) == "table" then
+    sanitized.fonts = {}
+    for fontName, fontPath in pairs(theme.fonts) do
+      if type(fontName) == "string" and type(fontPath) == "string" then
+        sanitized.fonts[fontName] = fontPath
+      end
+    end
+  end
+
+  -- Sanitize components (preserve as-is, they're complex)
+  if type(theme.components) == "table" then
+    sanitized.components = theme.components
+  end
+
+  -- Sanitize contentAutoSizingMultiplier
+  if type(theme.contentAutoSizingMultiplier) == "table" then
+    sanitized.contentAutoSizingMultiplier = {}
+    if type(theme.contentAutoSizingMultiplier.width) == "number" and theme.contentAutoSizingMultiplier.width > 0 then
+      sanitized.contentAutoSizingMultiplier.width = theme.contentAutoSizingMultiplier.width
+    end
+    if type(theme.contentAutoSizingMultiplier.height) == "number" and theme.contentAutoSizingMultiplier.height > 0 then
+      sanitized.contentAutoSizingMultiplier.height = theme.contentAutoSizingMultiplier.height
+    end
+  end
+
+  -- Sanitize atlas
+  if type(theme.atlas) == "string" then
+    sanitized.atlas = theme.atlas
+  end
+
+  return sanitized
+end
+
 return Theme

testing/__tests__/element_test.lua

@@ -0,0 +1,535 @@
+-- Test suite for Element.lua
+-- Tests element creation, size calculations, and basic functionality
+
+package.path = package.path .. ";./?.lua;./modules/?.lua"
+
+-- Load love stub before anything else
+require("testing.loveStub")
+
+local luaunit = require("testing.luaunit")
+
+-- Load FlexLove which properly initializes all dependencies
+local FlexLove = require("FlexLove")
+
+-- Test suite for Element creation
+TestElementCreation = {}
+
+function TestElementCreation:setUp()
+  -- Initialize FlexLove for each test
+  FlexLove.beginFrame(1920, 1080)
+end
+
+function TestElementCreation:tearDown()
+  FlexLove.endFrame()
+end
+
+function TestElementCreation:test_create_minimal_element()
+  local element = FlexLove.new({
+    id = "test1",
+    x = 10,
+    y = 20,
+    width = 100,
+    height = 50
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.id, "test1")
+  luaunit.assertEquals(element.x, 10)
+  luaunit.assertEquals(element.y, 20)
+  luaunit.assertEquals(element.width, 100)
+  luaunit.assertEquals(element.height, 50)
+end
+
+function TestElementCreation:test_element_with_text()
+  local element = FlexLove.new({
+    id = "text1",
+    x = 0,
+    y = 0,
+    width = 200,
+    height = 100,
+    text = "Hello World"
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.text, "Hello World")
+end
+
+function TestElementCreation:test_element_with_backgroundColor()
+  local element = FlexLove.new({
+    id = "colored1",
+    x = 0,
+    y = 0,
+    width = 100,
+    height = 100,
+    backgroundColor = {1, 0, 0, 1}
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertNotNil(element.backgroundColor)
+end
+
+function TestElementCreation:test_element_with_children()
+  local parent = FlexLove.new({
+    id = "parent1",
+    x = 0,
+    y = 0,
+    width = 300,
+    height = 200
+  })
+  
+  local child = FlexLove.new({
+    id = "child1",
+    x = 10,
+    y = 10,
+    width = 50,
+    height = 50,
+    parent = parent
+  })
+  
+  luaunit.assertNotNil(parent)
+  luaunit.assertNotNil(child)
+  luaunit.assertEquals(child.parent, parent)
+  luaunit.assertEquals(#parent.children, 1)
+  luaunit.assertEquals(parent.children[1], child)
+end
+
+function TestElementCreation:test_element_with_padding()
+  local element = FlexLove.new({
+    id = "padded1",
+    x = 0,
+    y = 0,
+    width = 200,
+    height = 100,
+    padding = { horizontal = 10, vertical = 10 }
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.padding.left, 10)
+  luaunit.assertEquals(element.padding.top, 10)
+  luaunit.assertEquals(element.padding.right, 10)
+  luaunit.assertEquals(element.padding.bottom, 10)
+end
+
+function TestElementCreation:test_element_with_margin()
+  local element = FlexLove.new({
+    id = "margined1",
+    x = 0,
+    y = 0,
+    width = 200,
+    height = 100,
+    margin = { horizontal = 5, vertical = 5 }
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.margin.left, 5)
+  luaunit.assertEquals(element.margin.top, 5)
+  luaunit.assertEquals(element.margin.right, 5)
+  luaunit.assertEquals(element.margin.bottom, 5)
+end
+
+-- Test suite for Element sizing
+TestElementSizing = {}
+
+function TestElementSizing:setUp()
+  FlexLove.beginFrame(1920, 1080)
+end
+
+function TestElementSizing:tearDown()
+  FlexLove.endFrame()
+end
+
+function TestElementSizing:test_getBorderBoxWidth()
+  local element = FlexLove.new({
+    id = "sized1",
+    x = 0,
+    y = 0,
+    width = 100,
+    height = 50
+  })
+  
+  local borderBoxWidth = element:getBorderBoxWidth()
+  luaunit.assertEquals(borderBoxWidth, 100)
+end
+
+function TestElementSizing:test_getBorderBoxHeight()
+  local element = FlexLove.new({
+    id = "sized2",
+    x = 0,
+    y = 0,
+    width = 100,
+    height = 50
+  })
+  
+  local borderBoxHeight = element:getBorderBoxHeight()
+  luaunit.assertEquals(borderBoxHeight, 50)
+end
+
+function TestElementSizing:test_getBounds()
+  local element = FlexLove.new({
+    id = "bounds1",
+    x = 10,
+    y = 20,
+    width = 100,
+    height = 50
+  })
+  
+  local bounds = element:getBounds()
+  luaunit.assertEquals(bounds.x, 10)
+  luaunit.assertEquals(bounds.y, 20)
+  luaunit.assertEquals(bounds.width, 100)
+  luaunit.assertEquals(bounds.height, 50)
+end
+
+function TestElementSizing:test_contains_point_inside()
+  local element = FlexLove.new({
+    id = "contains1",
+    x = 10,
+    y = 20,
+    width = 100,
+    height = 50
+  })
+  
+  local contains = element:contains(50, 40)
+  luaunit.assertTrue(contains)
+end
+
+function TestElementSizing:test_contains_point_outside()
+  local element = FlexLove.new({
+    id = "contains2",
+    x = 10,
+    y = 20,
+    width = 100,
+    height = 50
+  })
+  
+  local contains = element:contains(150, 100)
+  luaunit.assertFalse(contains)
+end
+
+function TestElementSizing:test_contains_point_on_edge()
+  local element = FlexLove.new({
+    id = "contains3",
+    x = 10,
+    y = 20,
+    width = 100,
+    height = 50
+  })
+  
+  -- Point on right edge
+  local contains = element:contains(110, 40)
+  luaunit.assertTrue(contains)
+  
+  -- Point on bottom edge
+  contains = element:contains(50, 70)
+  luaunit.assertTrue(contains)
+end
+
+-- Test suite for Element with units (units are resolved immediately after creation)
+TestElementUnits = {}
+
+function TestElementUnits:setUp()
+  FlexLove.beginFrame(1920, 1080)
+end
+
+function TestElementUnits:tearDown()
+  FlexLove.endFrame()
+end
+
+function TestElementUnits:test_element_with_percentage_width()
+  local parent = FlexLove.new({
+    id = "parent_pct",
+    x = 0,
+    y = 0,
+    width = 1000,
+    height = 500
+  })
+  
+  local child = FlexLove.new({
+    id = "child_pct",
+    x = 0,
+    y = 0,
+    width = "50%",
+    height = 100,
+    parent = parent
+  })
+  
+  luaunit.assertNotNil(child)
+  -- Width should be resolved to 500 (50% of parent's 1000)
+  luaunit.assertEquals(child.width, 500)
+end
+
+function TestElementUnits:test_element_with_viewport_units()
+  local element = FlexLove.new({
+    id = "viewport1",
+    x = 0,
+    y = 0,
+    width = "50vw",  -- 50% of viewport width (1920) = 960
+    height = "25vh"  -- 25% of viewport height (1080) = 270
+  })
+  
+  luaunit.assertNotNil(element)
+  -- Units should be resolved immediately to numbers
+  luaunit.assertEquals(type(element.width), "number")
+  luaunit.assertEquals(type(element.height), "number")
+  -- Should be positive values
+  luaunit.assertTrue(element.width > 0)
+  luaunit.assertTrue(element.height > 0)
+end
+
+-- Test suite for Element positioning
+TestElementPositioning = {}
+
+function TestElementPositioning:setUp()
+  FlexLove.beginFrame(1920, 1080)
+end
+
+function TestElementPositioning:tearDown()
+  FlexLove.endFrame()
+end
+
+function TestElementPositioning:test_element_absolute_position()
+  local element = FlexLove.new({
+    id = "abs1",
+    x = 100,
+    y = 200,
+    width = 50,
+    height = 50,
+    positioning = "absolute"
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.positioning, "absolute")
+end
+
+function TestElementPositioning:test_nested_element_positions()
+  local parent = FlexLove.new({
+    id = "nest_parent",
+    x = 100,
+    y = 100,
+    width = 300,
+    height = 200
+  })
+  
+  local child = FlexLove.new({
+    id = "nest_child",
+    x = 20,
+    y = 30,
+    width = 50,
+    height = 50,
+    parent = parent
+  })
+  
+  luaunit.assertNotNil(parent)
+  luaunit.assertNotNil(child)
+  -- Child positions are absolute in FlexLove, not relative to parent
+  -- So child.x = parent.x + relative_x = 100 + 20 = 120
+  luaunit.assertEquals(child.x, 120)
+  luaunit.assertEquals(child.y, 130)
+end
+
+-- Test suite for Element flex layout
+TestElementFlex = {}
+
+function TestElementFlex:setUp()
+  FlexLove.beginFrame(1920, 1080)
+end
+
+function TestElementFlex:tearDown()
+  FlexLove.endFrame()
+end
+
+function TestElementFlex:test_element_with_flex_direction()
+  local element = FlexLove.new({
+    id = "flex1",
+    x = 0,
+    y = 0,
+    width = 300,
+    height = 200,
+    positioning = "flex",
+    flexDirection = "horizontal"
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.flexDirection, "horizontal")
+end
+
+function TestElementFlex:test_element_with_flex_properties()
+  local parent = FlexLove.new({
+    id = "flex_parent",
+    x = 0,
+    y = 0,
+    width = 300,
+    height = 200,
+    positioning = "flex",
+    flexDirection = "horizontal"
+  })
+  
+  local element = FlexLove.new({
+    id = "flex2",
+    parent = parent,
+    width = 100,
+    height = 100,
+    flexGrow = 1,
+    flexShrink = 0,
+    flexBasis = "auto"
+  })
+  
+  luaunit.assertNotNil(element)
+  -- Just check element was created successfully
+  -- Flex properties are handled by LayoutEngine, not stored on element
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.parent, parent)
+end
+
+function TestElementFlex:test_element_with_gap()
+  local element = FlexLove.new({
+    id = "gap1",
+    x = 0,
+    y = 0,
+    width = 300,
+    height = 200,
+    positioning = "flex",
+    gap = 10
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.gap, 10)
+end
+
+-- Run tests if this file is executed directly
+if not _G.RUNNING_ALL_TESTS then
+  os.exit(luaunit.LuaUnit.run())
+end
+
+-- Test suite for Element styling properties
+TestElementStyling = {}
+
+function TestElementStyling:setUp()
+  FlexLove.beginFrame(1920, 1080)
+end
+
+function TestElementStyling:tearDown()
+  FlexLove.endFrame()
+end
+
+function TestElementStyling:test_element_with_border()
+  local element = FlexLove.new({
+    id = "bordered1",
+    x = 0,
+    y = 0,
+    width = 100,
+    height = 100,
+    border = 2
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.border, 2)
+end
+
+function TestElementStyling:test_element_with_corner_radius()
+  local element = FlexLove.new({
+    id = "rounded1",
+    x = 0,
+    y = 0,
+    width = 100,
+    height = 100,
+    cornerRadius = 10
+  })
+  
+  luaunit.assertNotNil(element)
+  -- Corner radius might be stored as a table
+  luaunit.assertNotNil(element.cornerRadius)
+end
+
+function TestElementStyling:test_element_with_text_align()
+  local element = FlexLove.new({
+    id = "aligned1",
+    x = 0,
+    y = 0,
+    width = 200,
+    height = 100,
+    text = "Centered Text",
+    textAlign = "center"
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.textAlign, "center")
+end
+
+function TestElementStyling:test_element_with_opacity()
+  local element = FlexLove.new({
+    id = "transparent1",
+    x = 0,
+    y = 0,
+    width = 100,
+    height = 100,
+    opacity = 0.5
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertEquals(element.opacity, 0.5)
+end
+
+function TestElementStyling:test_element_with_border_color()
+  local element = FlexLove.new({
+    id = "colored_border",
+    x = 0,
+    y = 0,
+    width = 100,
+    height = 100,
+    border = 2,
+    borderColor = {1, 0, 0, 1}
+  })
+  
+  luaunit.assertNotNil(element)
+  luaunit.assertNotNil(element.borderColor)
+end
+
+-- Test suite for Element methods
+TestElementMethods = {}
+
+function TestElementMethods:setUp()
+  FlexLove.beginFrame(1920, 1080)
+end
+
+function TestElementMethods:tearDown()
+  FlexLove.endFrame()
+end
+
+function TestElementMethods:test_element_setText()
+  local element = FlexLove.new({
+    id = "textual1",
+    x = 0,
+    y = 0,
+    width = 200,
+    height = 100,
+    text = "Initial"
+  })
+  
+  element:setText("Updated")
+  luaunit.assertEquals(element.text, "Updated")
+end
+
+function TestElementMethods:test_element_addChild()
+  local parent = FlexLove.new({
+    id = "parent_add",
+    x = 0,
+    y = 0,
+    width = 300,
+    height = 200
+  })
+  
+  local child = FlexLove.new({
+    id = "child_add",
+    x = 10,
+    y = 10,
+    width = 50,
+    height = 50
+  })
+  
+  parent:addChild(child)
+  luaunit.assertEquals(#parent.children, 1)
+  luaunit.assertEquals(parent.children[1], child)
+  luaunit.assertEquals(child.parent, parent)
+end
+

testing/__tests__/layout_engine_integration_test.lua

@@ -0,0 +1,441 @@
+-- Integration tests for LayoutEngine.lua
+-- Tests actual layout calculations with mock element structures
+
+package.path = package.path .. ";./?.lua;./modules/?.lua"
+
+-- Load love stub before anything else
+require("testing.loveStub")
+
+local luaunit = require("testing.luaunit")
+local LayoutEngine = require("modules.LayoutEngine")
+local Units = require("modules.Units")
+local utils = require("modules.utils")
+
+-- Mock dependencies
+local mockContext = {
+  getScaleFactors = function()
+    return 1, 1
+  end,
+  baseScale = 1,
+  _cachedViewport = { width = 1920, height = 1080 },
+}
+
+local mockErrorHandler = {
+  error = function(module, msg) end,
+  warn = function(module, msg) end,
+}
+
+local mockGrid = {
+  layoutGridItems = function(element) end,
+}
+
+local deps = {
+  utils = utils,
+  Grid = mockGrid,
+  Units = Units,
+  Context = mockContext,
+  ErrorHandler = mockErrorHandler,
+}
+
+-- Helper function to create mock element
+local function createMockElement(props)
+  return {
+    id = props.id or "mock",
+    x = props.x or 0,
+    y = props.y or 0,
+    width = props.width or 100,
+    height = props.height or 100,
+    absoluteX = props.absoluteX or 0,
+    absoluteY = props.absoluteY or 0,
+    marginLeft = props.marginLeft or 0,
+    marginTop = props.marginTop or 0,
+    marginRight = props.marginRight or 0,
+    marginBottom = props.marginBottom or 0,
+    children = props.children or {},
+    parent = props.parent,
+    isHidden = props.isHidden or false,
+    flexGrow = props.flexGrow or 0,
+    flexShrink = props.flexShrink or 1,
+    flexBasis = props.flexBasis or "auto",
+    alignSelf = props.alignSelf,
+    minWidth = props.minWidth,
+    maxWidth = props.maxWidth,
+    minHeight = props.minHeight,
+    maxHeight = props.maxHeight,
+    text = props.text,
+    _layout = nil,
+    recalculateUnits = function() end,
+    layoutChildren = function() end,
+  }
+end
+
+-- Test suite for layoutChildren with flex layout
+TestLayoutChildrenFlex = {}
+
+function TestLayoutChildrenFlex:test_layoutChildren_horizontal_flex_start()
+  local props = {
+    positioning = utils.enums.Positioning.FLEX,
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    justifyContent = utils.enums.JustifyContent.FLEX_START,
+    alignItems = utils.enums.AlignItems.FLEX_START,
+    gap = 10,
+  }
+  local layout = LayoutEngine.new(props, deps)
+
+  local parent = createMockElement({
+    id = "parent",
+    width = 300,
+    height = 100,
+  })
+
+  local child1 = createMockElement({
+    id = "child1",
+    width = 50,
+    height = 30,
+    parent = parent,
+  })
+
+  local child2 = createMockElement({
+    id = "child2",
+    width = 60,
+    height = 40,
+    parent = parent,
+  })
+
+  parent.children = { child1, child2 }
+  parent._layout = layout
+
+  layout:initialize(parent)
+  layout:layoutChildren()
+
+  -- Verify layout was calculated (children positions should be set)
+  -- Child1 should be at (0, 0)
+  luaunit.assertEquals(child1.x, 0)
+  luaunit.assertEquals(child1.y, 0)
+
+  -- Child2 should be at (50 + gap, 0) = (60, 0)
+  luaunit.assertEquals(child2.x, 60)
+  luaunit.assertEquals(child2.y, 0)
+end
+
+function TestLayoutChildrenFlex:test_layoutChildren_vertical_flex_start()
+  local props = {
+    positioning = utils.enums.Positioning.FLEX,
+    flexDirection = utils.enums.FlexDirection.VERTICAL,
+    justifyContent = utils.enums.JustifyContent.FLEX_START,
+    alignItems = utils.enums.AlignItems.FLEX_START,
+    gap = 5,
+  }
+  local layout = LayoutEngine.new(props, deps)
+
+  local parent = createMockElement({
+    id = "parent",
+    width = 100,
+    height = 200,
+  })
+
+  local child1 = createMockElement({
+    id = "child1",
+    width = 50,
+    height = 30,
+    parent = parent,
+  })
+
+  local child2 = createMockElement({
+    id = "child2",
+    width = 60,
+    height = 40,
+    parent = parent,
+  })
+
+  parent.children = { child1, child2 }
+  parent._layout = layout
+
+  layout:initialize(parent)
+  layout:layoutChildren()
+
+  -- Verify layout was calculated
+  luaunit.assertEquals(child1.x, 0)
+  luaunit.assertEquals(child1.y, 0)
+
+  -- Child2 should be below child1 with gap
+  luaunit.assertEquals(child2.x, 0)
+  luaunit.assertEquals(child2.y, 35) -- 30 + 5
+end
+
+function TestLayoutChildrenFlex:test_layoutChildren_with_margins()
+  local props = {
+    positioning = utils.enums.Positioning.FLEX,
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    justifyContent = utils.enums.JustifyContent.FLEX_START,
+    gap = 0,
+  }
+  local layout = LayoutEngine.new(props, deps)
+
+  local parent = createMockElement({
+    id = "parent",
+    width = 300,
+    height = 100,
+  })
+
+  local child1 = createMockElement({
+    id = "child1",
+    width = 50,
+    height = 30,
+    marginLeft = 10,
+    marginRight = 5,
+    parent = parent,
+  })
+
+  parent.children = { child1 }
+  parent._layout = layout
+
+  layout:initialize(parent)
+  layout:layoutChildren()
+
+  -- Child should be offset by left margin
+  luaunit.assertEquals(child1.x, 10)
+end
+
+function TestLayoutChildrenFlex:test_layoutChildren_with_hidden_children()
+  local props = {
+    positioning = utils.enums.Positioning.FLEX,
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    gap = 10,
+  }
+  local layout = LayoutEngine.new(props, deps)
+
+  local parent = createMockElement({
+    id = "parent",
+    width = 300,
+    height = 100,
+  })
+
+  local child1 = createMockElement({
+    id = "child1",
+    width = 50,
+    height = 30,
+    parent = parent,
+  })
+
+  local child2 = createMockElement({
+    id = "child2",
+    width = 60,
+    height = 40,
+    isHidden = true,
+    parent = parent,
+  })
+
+  local child3 = createMockElement({
+    id = "child3",
+    width = 70,
+    height = 35,
+    parent = parent,
+  })
+
+  parent.children = { child1, child2, child3 }
+  parent._layout = layout
+
+  layout:initialize(parent)
+  layout:layoutChildren()
+
+  -- Child2 should be skipped, so child3 should be positioned after child1
+  luaunit.assertEquals(child1.x, 0)
+  luaunit.assertEquals(child3.x, 60) -- 50 + gap (10)
+end
+
+function TestLayoutChildrenFlex:test_layoutChildren_center()
+  local props = {
+    positioning = utils.enums.Positioning.FLEX,
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    justifyContent = utils.enums.JustifyContent.CENTER,
+    alignItems = utils.enums.AlignItems.CENTER,
+    gap = 10,
+  }
+  local layout = LayoutEngine.new(props, deps)
+
+  local parent = createMockElement({
+    id = "parent",
+    width = 300,
+    height = 100,
+  })
+
+  local child1 = createMockElement({
+    id = "child1",
+    width = 50,
+    height = 30,
+    parent = parent,
+  })
+
+  local child2 = createMockElement({
+    id = "child2",
+    width = 60,
+    height = 40,
+    parent = parent,
+  })
+
+  parent.children = { child1, child2 }
+  parent._layout = layout
+
+  layout:initialize(parent)
+  layout:layoutChildren()
+
+  -- Children should be centered
+  -- Total width needed: 50 + 10 + 60 = 120
+  -- Remaining space: 300 - 120 = 180
+  -- Center offset: 180 / 2 = 90
+  luaunit.assertEquals(child1.x, 90)
+  luaunit.assertEquals(child2.x, 150) -- 90 + 50 + 10
+
+  -- Vertical centering
+  -- Child1 height 30, container 100, offset = (100-30)/2 = 35
+  luaunit.assertEquals(child1.y, 35)
+  -- Child2 height 40, offset = (100-40)/2 = 30
+  luaunit.assertEquals(child2.y, 30)
+end
+
+function TestLayoutChildrenFlex:test_layoutChildren_space_between()
+  local props = {
+    positioning = utils.enums.Positioning.FLEX,
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    justifyContent = utils.enums.JustifyContent.SPACE_BETWEEN,
+    gap = 0,
+  }
+  local layout = LayoutEngine.new(props, deps)
+
+  local parent = createMockElement({
+    id = "parent",
+    width = 300,
+    height = 100,
+  })
+
+  local child1 = createMockElement({
+    id = "child1",
+    width = 50,
+    height = 30,
+    parent = parent,
+  })
+
+  local child2 = createMockElement({
+    id = "child2",
+    width = 60,
+    height = 40,
+    parent = parent,
+  })
+
+  parent.children = { child1, child2 }
+  parent._layout = layout
+
+  layout:initialize(parent)
+  layout:layoutChildren()
+
+  -- First child at start
+  luaunit.assertEquals(child1.x, 0)
+
+  -- Last child at end: 300 - 60 = 240
+  luaunit.assertEquals(child2.x, 240)
+end
+
+-- Test suite for applyPositioningOffsets
+TestApplyPositioningOffsets = {}
+
+function TestApplyPositioningOffsets:test_applyPositioningOffsets_relative()
+  local props = {
+    positioning = utils.enums.Positioning.FLEX,
+  }
+  local layout = LayoutEngine.new(props, deps)
+
+  local parent = createMockElement({
+    id = "parent",
+    x = 100,
+    y = 50,
+  })
+
+  local child = createMockElement({
+    id = "child",
+    x = 20,
+    y = 30,
+    parent = parent,
+  })
+
+  layout:initialize(parent)
+  layout:applyPositioningOffsets(child)
+
+  -- Relative positioning: child keeps its x, y
+  luaunit.assertEquals(child.x, 20)
+  luaunit.assertEquals(child.y, 30)
+end
+
+function TestApplyPositioningOffsets:test_applyPositioningOffsets_absolute()
+  local props = {
+    positioning = utils.enums.Positioning.ABSOLUTE,
+  }
+  local layout = LayoutEngine.new(props, deps)
+
+  local parent = createMockElement({
+    id = "parent",
+    absoluteX = 100,
+    absoluteY = 50,
+    width = 300,
+    height = 200,
+  })
+
+  local child = createMockElement({
+    id = "child",
+    x = 20,
+    y = 30,
+    parent = parent,
+  })
+
+  layout:initialize(parent)
+  layout:applyPositioningOffsets(child)
+
+  -- Absolute positioning: child.x, child.y are relative to parent
+  luaunit.assertEquals(child.absoluteX, 120) -- 100 + 20
+  luaunit.assertEquals(child.absoluteY, 80) -- 50 + 30
+end
+
+-- Test suite for grid layout
+TestLayoutChildrenGrid = {}
+
+function TestLayoutChildrenGrid:test_layoutChildren_grid_delegates_to_Grid()
+  local gridCalled = false
+  local mockGridForTest = {
+    layoutGridItems = function(element)
+      gridCalled = true
+    end,
+  }
+
+  local depsWithMockGrid = {
+    utils = utils,
+    Grid = mockGridForTest,
+    Units = Units,
+    Context = mockContext,
+    ErrorHandler = mockErrorHandler,
+  }
+
+  local props = {
+    positioning = utils.enums.Positioning.GRID,
+    gridRows = 2,
+    gridColumns = 2,
+  }
+  local layout = LayoutEngine.new(props, depsWithMockGrid)
+
+  local parent = createMockElement({
+    id = "parent",
+    width = 300,
+    height = 200,
+  })
+
+  parent._layout = layout
+  layout:initialize(parent)
+  layout:layoutChildren()
+
+  -- Verify Grid.layoutGridItems was called
+  luaunit.assertTrue(gridCalled)
+end
+
+-- Run tests if this file is executed directly
+if not _G.RUNNING_ALL_TESTS then
+  os.exit(luaunit.LuaUnit.run())
+end

testing/__tests__/layout_engine_test.lua

@@ -0,0 +1,661 @@
+-- Test suite for LayoutEngine.lua module
+-- Tests layout engine initialization and basic layout calculations
+
+package.path = package.path .. ";./?.lua;./modules/?.lua"
+
+-- Load love stub before anything else
+require("testing.loveStub")
+
+local luaunit = require("testing.luaunit")
+local LayoutEngine = require("modules.LayoutEngine")
+local Units = require("modules.Units")
+local utils = require("modules.utils")
+
+-- Mock dependencies
+local mockContext = {
+  getScaleFactors = function()
+    return 1, 1
+  end,
+  baseScale = nil,
+  _cachedViewport = nil,
+}
+
+local mockErrorHandler = {
+  error = function(module, msg) end,
+  warn = function(module, msg) end,
+}
+
+local mockGrid = {
+  layoutGridItems = function(element) end,
+}
+
+local deps = {
+  utils = utils,
+  Grid = mockGrid,
+  Units = Units,
+  Context = mockContext,
+  ErrorHandler = mockErrorHandler,
+}
+
+-- Test suite for LayoutEngine.new()
+TestLayoutEngineNew = {}
+
+function TestLayoutEngineNew:testNewWithDefaults()
+  local layout = LayoutEngine.new({}, deps)
+  luaunit.assertNotNil(layout)
+  luaunit.assertEquals(layout.positioning, utils.enums.Positioning.FLEX)
+  luaunit.assertEquals(layout.flexDirection, utils.enums.FlexDirection.HORIZONTAL)
+  luaunit.assertEquals(layout.justifyContent, utils.enums.JustifyContent.FLEX_START)
+  luaunit.assertEquals(layout.alignItems, utils.enums.AlignItems.STRETCH)
+  luaunit.assertEquals(layout.alignContent, utils.enums.AlignContent.STRETCH)
+  luaunit.assertEquals(layout.flexWrap, utils.enums.FlexWrap.NOWRAP)
+  luaunit.assertEquals(layout.gap, 10)
+end
+
+function TestLayoutEngineNew:testNewWithCustomProps()
+  local layout = LayoutEngine.new({
+    positioning = utils.enums.Positioning.GRID,
+    flexDirection = utils.enums.FlexDirection.VERTICAL,
+    justifyContent = utils.enums.JustifyContent.CENTER,
+    alignItems = utils.enums.AlignItems.CENTER,
+    gap = 20,
+    gridRows = 3,
+    gridColumns = 4,
+  }, deps)
+
+  luaunit.assertEquals(layout.positioning, utils.enums.Positioning.GRID)
+  luaunit.assertEquals(layout.flexDirection, utils.enums.FlexDirection.VERTICAL)
+  luaunit.assertEquals(layout.justifyContent, utils.enums.JustifyContent.CENTER)
+  luaunit.assertEquals(layout.alignItems, utils.enums.AlignItems.CENTER)
+  luaunit.assertEquals(layout.gap, 20)
+  luaunit.assertEquals(layout.gridRows, 3)
+  luaunit.assertEquals(layout.gridColumns, 4)
+end
+
+function TestLayoutEngineNew:testNewStoresDependencies()
+  local layout = LayoutEngine.new({}, deps)
+  luaunit.assertNotNil(layout._Grid)
+  luaunit.assertNotNil(layout._Units)
+  luaunit.assertNotNil(layout._Context)
+  luaunit.assertNotNil(layout._ErrorHandler)
+end
+
+-- Test suite for LayoutEngine:initialize()
+TestLayoutEngineInitialize = {}
+
+function TestLayoutEngineInitialize:testInitialize()
+  local layout = LayoutEngine.new({}, deps)
+  local mockElement = { id = "test" }
+
+  layout:initialize(mockElement)
+  luaunit.assertEquals(layout.element, mockElement)
+end
+
+-- Test suite for LayoutEngine:calculateAutoWidth()
+TestLayoutEngineAutoWidth = {}
+
+function TestLayoutEngineAutoWidth:testAutoWidthNoElement()
+  local layout = LayoutEngine.new({}, deps)
+  local width = layout:calculateAutoWidth()
+  luaunit.assertEquals(width, 0)
+end
+
+function TestLayoutEngineAutoWidth:testAutoWidthNoChildren()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+  }, deps)
+
+  local mockElement = {
+    children = {},
+    calculateTextWidth = function()
+      return 100
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local width = layout:calculateAutoWidth()
+  luaunit.assertEquals(width, 100) -- Just text width
+end
+
+function TestLayoutEngineAutoWidth:testAutoWidthHorizontalWithGap()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    gap = 10,
+  }, deps)
+
+  local mockChild1 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 50
+    end,
+  }
+  local mockChild2 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 60
+    end,
+  }
+  local mockChild3 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 70
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild1, mockChild2, mockChild3 },
+    calculateTextWidth = function()
+      return 0
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local width = layout:calculateAutoWidth()
+  -- 50 + 60 + 70 = 180, plus 2 gaps (10 each) = 200
+  luaunit.assertEquals(width, 200)
+end
+
+function TestLayoutEngineAutoWidth:testAutoWidthVerticalTakesMax()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.VERTICAL,
+    gap = 10,
+  }, deps)
+
+  local mockChild1 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 50
+    end,
+  }
+  local mockChild2 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 150
+    end,
+  }
+  local mockChild3 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 75
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild1, mockChild2, mockChild3 },
+    calculateTextWidth = function()
+      return 0
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local width = layout:calculateAutoWidth()
+  -- Should take maximum width (150)
+  luaunit.assertEquals(width, 150)
+end
+
+function TestLayoutEngineAutoWidth:testAutoWidthSkipsAbsoluteChildren()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    gap = 10,
+  }, deps)
+
+  local mockChild1 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 50
+    end,
+  }
+  local mockChild2 = {
+    _explicitlyAbsolute = true, -- Should be skipped
+    getBorderBoxWidth = function()
+      return 1000
+    end,
+  }
+  local mockChild3 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 60
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild1, mockChild2, mockChild3 },
+    calculateTextWidth = function()
+      return 0
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local width = layout:calculateAutoWidth()
+  -- 50 + 60 = 110, plus 1 gap (10) = 120 (mockChild2 is skipped)
+  luaunit.assertEquals(width, 120)
+end
+
+-- Test suite for LayoutEngine:calculateAutoHeight()
+TestLayoutEngineAutoHeight = {}
+
+function TestLayoutEngineAutoHeight:testAutoHeightNoElement()
+  local layout = LayoutEngine.new({}, deps)
+  local height = layout:calculateAutoHeight()
+  luaunit.assertEquals(height, 0)
+end
+
+function TestLayoutEngineAutoHeight:testAutoHeightNoChildren()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.VERTICAL,
+  }, deps)
+
+  local mockElement = {
+    children = {},
+    calculateTextHeight = function()
+      return 50
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local height = layout:calculateAutoHeight()
+  luaunit.assertEquals(height, 50) -- Just text height
+end
+
+function TestLayoutEngineAutoHeight:testAutoHeightVerticalWithGap()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.VERTICAL,
+    gap = 5,
+  }, deps)
+
+  local mockChild1 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 30
+    end,
+  }
+  local mockChild2 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 40
+    end,
+  }
+  local mockChild3 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 50
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild1, mockChild2, mockChild3 },
+    calculateTextHeight = function()
+      return 0
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local height = layout:calculateAutoHeight()
+  -- 30 + 40 + 50 = 120, plus 2 gaps (5 each) = 130
+  luaunit.assertEquals(height, 130)
+end
+
+function TestLayoutEngineAutoHeight:testAutoHeightHorizontalTakesMax()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    gap = 5,
+  }, deps)
+
+  local mockChild1 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 30
+    end,
+  }
+  local mockChild2 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 100
+    end,
+  }
+  local mockChild3 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 50
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild1, mockChild2, mockChild3 },
+    calculateTextHeight = function()
+      return 0
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local height = layout:calculateAutoHeight()
+  -- Should take maximum height (100)
+  luaunit.assertEquals(height, 100)
+end
+
+function TestLayoutEngineAutoHeight:testAutoHeightSkipsAbsoluteChildren()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.VERTICAL,
+    gap = 5,
+  }, deps)
+
+  local mockChild1 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 30
+    end,
+  }
+  local mockChild2 = {
+    _explicitlyAbsolute = true, -- Should be skipped
+    getBorderBoxHeight = function()
+      return 1000
+    end,
+  }
+  local mockChild3 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 40
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild1, mockChild2, mockChild3 },
+    calculateTextHeight = function()
+      return 0
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local height = layout:calculateAutoHeight()
+  -- 30 + 40 = 70, plus 1 gap (5) = 75 (mockChild2 is skipped)
+  luaunit.assertEquals(height, 75)
+end
+
+-- Test suite for LayoutEngine:applyPositioningOffsets()
+TestLayoutEnginePositioningOffsets = {}
+
+function TestLayoutEnginePositioningOffsets:testApplyOffsetsNilChild()
+  local layout = LayoutEngine.new({}, deps)
+  -- Should not error
+  layout:applyPositioningOffsets(nil)
+end
+
+function TestLayoutEnginePositioningOffsets:testApplyOffsetsNoParent()
+  local layout = LayoutEngine.new({}, deps)
+  local mockChild = {
+    parent = nil,
+    top = 10,
+  }
+  -- Should not error, just return early
+  layout:applyPositioningOffsets(mockChild)
+end
+
+function TestLayoutEnginePositioningOffsets:testApplyTopOffset()
+  local layout = LayoutEngine.new({}, deps)
+
+  local mockParent = {
+    x = 100,
+    y = 200,
+    padding = { left = 10, top = 20, right = 10, bottom = 20 },
+  }
+
+  local mockChild = {
+    parent = mockParent,
+    positioning = utils.enums.Positioning.ABSOLUTE,
+    _explicitlyAbsolute = true,
+    x = 0,
+    y = 0,
+    top = 30,
+  }
+
+  layout:applyPositioningOffsets(mockChild)
+  -- y should be parent.y + parent.padding.top + top
+  -- 200 + 20 + 30 = 250
+  luaunit.assertEquals(mockChild.y, 250)
+end
+
+function TestLayoutEnginePositioningOffsets:testApplyLeftOffset()
+  local layout = LayoutEngine.new({}, deps)
+
+  local mockParent = {
+    x = 100,
+    y = 200,
+    padding = { left = 10, top = 20, right = 10, bottom = 20 },
+  }
+
+  local mockChild = {
+    parent = mockParent,
+    positioning = utils.enums.Positioning.ABSOLUTE,
+    _explicitlyAbsolute = true,
+    x = 0,
+    y = 0,
+    left = 40,
+  }
+
+  layout:applyPositioningOffsets(mockChild)
+  -- x should be parent.x + parent.padding.left + left
+  -- 100 + 10 + 40 = 150
+  luaunit.assertEquals(mockChild.x, 150)
+end
+
+function TestLayoutEnginePositioningOffsets:testApplyBottomOffset()
+  local layout = LayoutEngine.new({}, deps)
+
+  local mockParent = {
+    x = 100,
+    y = 200,
+    width = 400,
+    height = 300,
+    padding = { left = 10, top = 20, right = 10, bottom = 20 },
+  }
+
+  local mockChild = {
+    parent = mockParent,
+    positioning = utils.enums.Positioning.ABSOLUTE,
+    _explicitlyAbsolute = true,
+    x = 0,
+    y = 0,
+    bottom = 50,
+    getBorderBoxHeight = function()
+      return 80
+    end,
+  }
+
+  layout:applyPositioningOffsets(mockChild)
+  -- y should be parent.y + parent.padding.top + parent.height - bottom - childHeight
+  -- 200 + 20 + 300 - 50 - 80 = 390
+  luaunit.assertEquals(mockChild.y, 390)
+end
+
+function TestLayoutEnginePositioningOffsets:testApplyRightOffset()
+  local layout = LayoutEngine.new({}, deps)
+
+  local mockParent = {
+    x = 100,
+    y = 200,
+    width = 400,
+    height = 300,
+    padding = { left = 10, top = 20, right = 10, bottom = 20 },
+  }
+
+  local mockChild = {
+    parent = mockParent,
+    positioning = utils.enums.Positioning.ABSOLUTE,
+    _explicitlyAbsolute = true,
+    x = 0,
+    y = 0,
+    right = 60,
+    getBorderBoxWidth = function()
+      return 100
+    end,
+  }
+
+  layout:applyPositioningOffsets(mockChild)
+  -- x should be parent.x + parent.padding.left + parent.width - right - childWidth
+  -- 100 + 10 + 400 - 60 - 100 = 350
+  luaunit.assertEquals(mockChild.x, 350)
+end
+
+function TestLayoutEnginePositioningOffsets:testSkipsFlexChildren()
+  local layout = LayoutEngine.new({}, deps)
+
+  local mockParent = {
+    x = 100,
+    y = 200,
+    padding = { left = 10, top = 20, right = 10, bottom = 20 },
+  }
+
+  local mockChild = {
+    parent = mockParent,
+    positioning = utils.enums.Positioning.ABSOLUTE,
+    _explicitlyAbsolute = false, -- Participates in flex layout
+    x = 500,
+    y = 600,
+    top = 30,
+    left = 40,
+  }
+
+  layout:applyPositioningOffsets(mockChild)
+  -- Should not apply offsets for flex children
+  luaunit.assertEquals(mockChild.x, 500) -- Unchanged
+  luaunit.assertEquals(mockChild.y, 600) -- Unchanged
+end
+
+-- Test suite for LayoutEngine:layoutChildren()
+TestLayoutEngineLayoutChildren = {}
+
+function TestLayoutEngineLayoutChildren:testLayoutChildrenNoElement()
+  local layout = LayoutEngine.new({}, deps)
+  -- Should not error
+  layout:layoutChildren()
+end
+
+function TestLayoutEngineLayoutChildren:testLayoutChildrenNoChildren()
+  local layout = LayoutEngine.new({}, deps)
+  local mockElement = {
+    children = {},
+  }
+  layout:initialize(mockElement)
+  -- Should not error
+  layout:layoutChildren()
+end
+
+function TestLayoutEngineLayoutChildren:testLayoutChildrenAbsolutePositioning()
+  local layout = LayoutEngine.new({
+    positioning = utils.enums.Positioning.ABSOLUTE,
+  }, deps)
+
+  local mockElement = {
+    children = {},
+    padding = { left = 0, top = 0, right = 0, bottom = 0 },
+  }
+  layout:initialize(mockElement)
+
+  -- Should handle absolute positioning (doesn't layout children, just applies offsets)
+  layout:layoutChildren()
+end
+
+function TestLayoutEngineLayoutChildren:testLayoutChildrenRelativePositioning()
+  local layout = LayoutEngine.new({
+    positioning = utils.enums.Positioning.RELATIVE,
+  }, deps)
+
+  local mockElement = {
+    children = {},
+    padding = { left = 0, top = 0, right = 0, bottom = 0 },
+  }
+  layout:initialize(mockElement)
+
+  -- Should handle relative positioning (doesn't layout children, just applies offsets)
+  layout:layoutChildren()
+end
+
+-- Edge cases
+TestLayoutEngineEdgeCases = {}
+
+function TestLayoutEngineEdgeCases:testAutoWidthWithZeroGap()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    gap = 0,
+  }, deps)
+
+  local mockChild1 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 50
+    end,
+  }
+  local mockChild2 = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 60
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild1, mockChild2 },
+    calculateTextWidth = function()
+      return 0
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local width = layout:calculateAutoWidth()
+  luaunit.assertEquals(width, 110) -- 50 + 60, no gaps
+end
+
+function TestLayoutEngineEdgeCases:testAutoHeightWithSingleChild()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.VERTICAL,
+    gap = 10,
+  }, deps)
+
+  local mockChild = {
+    _explicitlyAbsolute = false,
+    getBorderBoxHeight = function()
+      return 100
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild },
+    calculateTextHeight = function()
+      return 0
+    end,
+  }
+  layout:initialize(mockElement)
+
+  local height = layout:calculateAutoHeight()
+  luaunit.assertEquals(height, 100) -- No gaps with single child
+end
+
+function TestLayoutEngineEdgeCases:testAutoWidthWithTextAndChildren()
+  local layout = LayoutEngine.new({
+    flexDirection = utils.enums.FlexDirection.HORIZONTAL,
+    gap = 10,
+  }, deps)
+
+  local mockChild = {
+    _explicitlyAbsolute = false,
+    getBorderBoxWidth = function()
+      return 50
+    end,
+  }
+
+  local mockElement = {
+    children = { mockChild },
+    calculateTextWidth = function()
+      return 100
+    end, -- Has text
+  }
+  layout:initialize(mockElement)
+
+  local width = layout:calculateAutoWidth()
+  -- Text width (100) + child width (50) = 150
+  luaunit.assertEquals(width, 150)
+end
+
+-- Run tests if not running as part of a suite
+if not _G.RUNNING_ALL_TESTS then
+  os.exit(luaunit.LuaUnit.run())
+end

testing/__tests__/texteditor_sanitization_test.lua

@@ -12,12 +12,14 @@ local Color = require("modules.Color")
 -- Mock dependencies
 local mockContext = {
   _immediateMode = false,
-  _focusedElement = nil
+  _focusedElement = nil,
 }
 
 local mockStateManager = {
-  getState = function() return nil end,
+  getState = function()
-  setState = function() end
+    return nil
+  end,
+  setState = function() end,
 }
 
 -- Test Suite for TextEditor Sanitization
@@ -31,7 +33,7 @@ function TestTextEditorSanitization:_createEditor(config)
     Context = mockContext,
     StateManager = mockStateManager,
     Color = Color,
-    utils = utils
+    utils = utils,
   }
   return TextEditor.new(config, deps)
 end
@@ -83,7 +85,7 @@ end
 function TestTextEditorSanitization:test_initial_text_is_sanitized()
   local editor = self:_createEditor({
     editable = true,
-    text = "Initial\x00Text\x01"
+    text = "Initial\x00Text\x01",
   })
   luaunit.assertEquals(editor:getText(), "InitialText")
 end
@@ -92,7 +94,7 @@ function TestTextEditorSanitization:test_initial_text_preserved_when_disabled()
   local editor = self:_createEditor({
     editable = true,
     sanitize = false,
-    text = "Initial\x00Text"
+    text = "Initial\x00Text",
   })
   luaunit.assertEquals(editor:getText(), "Initial\x00Text")
 end
@@ -161,7 +163,7 @@ function TestTextEditorSanitization:test_allowNewlines_explicit_false()
   local editor = self:_createEditor({
     editable = true,
     multiline = true,
-    allowNewlines = false
+    allowNewlines = false,
   })
   editor:setText("Line1\nLine2")
   luaunit.assertEquals(editor:getText(), "Line1Line2")
@@ -178,7 +180,7 @@ end
 function TestTextEditorSanitization:test_tabs_removed_when_disabled()
   local editor = self:_createEditor({
     editable = true,
-    allowTabs = false
+    allowTabs = false,
   })
   editor:setText("Hello\tWorld")
   luaunit.assertEquals(editor:getText(), "HelloWorld")
@@ -193,7 +195,7 @@ function TestTextEditorSanitization:test_custom_sanitizer_used()
 
   local editor = self:_createEditor({
     editable = true,
-    customSanitizer = customSanitizer
+    customSanitizer = customSanitizer,
   })
   editor:setText("hello world")
   luaunit.assertEquals(editor:getText(), "HELLO WORLD")
@@ -207,7 +209,7 @@ function TestTextEditorSanitization:test_custom_sanitizer_with_control_chars()
 
   local editor = self:_createEditor({
     editable = true,
-    customSanitizer = customSanitizer
+    customSanitizer = customSanitizer,
   })
   editor:setText("Hello\x00World\x01")
   luaunit.assertEquals(editor:getText(), "Hello*World*")

testing/__tests__/theme_core_test.lua

@@ -0,0 +1,302 @@
+-- Test suite for Theme.lua core functionality
+-- Tests theme creation, registration, and retrieval functions
+
+package.path = package.path .. ";./?.lua;./modules/?.lua"
+
+-- Load love stub before anything else
+require("testing.loveStub")
+
+local luaunit = require("testing.luaunit")
+local Theme = require("modules.Theme")
+local Color = require("modules.Color")
+
+-- Test suite for Theme.new()
+TestThemeNew = {}
+
+function TestThemeNew:setUp()
+  -- Clear any registered themes before each test
+  -- Note: We can't access the themes table directly, but we can work around it
+end
+
+function TestThemeNew:test_new_minimal_theme()
+  local def = {
+    name = "Minimal Theme",
+  }
+  local theme = Theme.new(def)
+  luaunit.assertNotNil(theme)
+  luaunit.assertEquals(theme.name, "Minimal Theme")
+end
+
+function TestThemeNew:test_new_theme_with_components()
+  local def = {
+    name = "Test Theme",
+    components = {
+      button = {
+        atlas = "path/to/button.png",
+      },
+    },
+  }
+  local theme = Theme.new(def)
+  luaunit.assertNotNil(theme)
+  luaunit.assertEquals(theme.name, "Test Theme")
+  luaunit.assertNotNil(theme.components.button)
+end
+
+function TestThemeNew:test_new_theme_with_colors()
+  local def = {
+    name = "Colored Theme",
+    colors = {
+      primary = Color.new(1, 0, 0, 1),
+      secondary = Color.new(0, 1, 0, 1),
+    },
+  }
+  local theme = Theme.new(def)
+  luaunit.assertNotNil(theme)
+  luaunit.assertNotNil(theme.colors.primary)
+  luaunit.assertNotNil(theme.colors.secondary)
+end
+
+function TestThemeNew:test_new_theme_with_fonts()
+  local def = {
+    name = "Font Theme",
+    fonts = {
+      default = "path/to/font.ttf",
+    },
+  }
+  local theme = Theme.new(def)
+  luaunit.assertNotNil(theme)
+  luaunit.assertNotNil(theme.fonts.default)
+  luaunit.assertEquals(theme.fonts.default, "path/to/font.ttf")
+end
+
+function TestThemeNew:test_new_theme_with_multiplier()
+  local def = {
+    name = "Multiplier Theme",
+    contentAutoSizingMultiplier = {
+      width = 1.5,
+      height = 2.0,
+    },
+  }
+  local theme = Theme.new(def)
+  luaunit.assertNotNil(theme)
+  luaunit.assertNotNil(theme.contentAutoSizingMultiplier)
+  luaunit.assertEquals(theme.contentAutoSizingMultiplier.width, 1.5)
+  luaunit.assertEquals(theme.contentAutoSizingMultiplier.height, 2.0)
+end
+
+function TestThemeNew:test_new_theme_without_name_fails()
+  local def = {}
+  luaunit.assertErrorMsgContains("name", function()
+    Theme.new(def)
+  end)
+end
+
+function TestThemeNew:test_new_theme_with_nil_fails()
+  luaunit.assertErrorMsgContains("nil", function()
+    Theme.new(nil)
+  end)
+end
+
+function TestThemeNew:test_new_theme_with_non_table_fails()
+  luaunit.assertErrorMsgContains("table", function()
+    Theme.new("not a table")
+  end)
+end
+
+-- Test suite for Theme registration and retrieval
+TestThemeRegistration = {}
+
+function TestThemeRegistration:test_setActive_with_theme_object()
+  local def = {
+    name = "Active Theme",
+  }
+  local theme = Theme.new(def)
+  Theme.setActive(theme)
+
+  local active = Theme.getActive()
+  luaunit.assertNotNil(active)
+  luaunit.assertEquals(active.name, "Active Theme")
+end
+
+function TestThemeRegistration:test_getActive_returns_nil_initially()
+  -- This test assumes no theme is active, but other tests may have set one
+  -- So we'll just check that getActive returns something or nil
+  local active = Theme.getActive()
+  -- Just verify it doesn't error
+  luaunit.assertTrue(active == nil or type(active) == "table")
+end
+
+function TestThemeRegistration:test_hasActive_returns_boolean()
+  local hasActive = Theme.hasActive()
+  luaunit.assertTrue(type(hasActive) == "boolean")
+end
+
+function TestThemeRegistration:test_get_returns_nil_for_unregistered_theme()
+  -- Theme.get() looks up themes in the registered themes table
+  -- Themes created with Theme.new() and setActive() are not automatically registered
+  local def = {
+    name = "Unregistered Theme",
+  }
+  local theme = Theme.new(def)
+  Theme.setActive(theme)
+
+  -- This should return nil because the theme was not loaded from a file
+  local retrieved = Theme.get("Unregistered Theme")
+  luaunit.assertNil(retrieved)
+end
+
+function TestThemeRegistration:test_get_returns_nil_for_nonexistent()
+  local retrieved = Theme.get("Nonexistent Theme 12345")
+  luaunit.assertNil(retrieved)
+end
+
+function TestThemeRegistration:test_getRegisteredThemes_returns_table()
+  local themes = Theme.getRegisteredThemes()
+  luaunit.assertNotNil(themes)
+  luaunit.assertEquals(type(themes), "table")
+end
+
+-- Test suite for Theme.getComponent()
+TestThemeComponent = {}
+
+function TestThemeComponent:setUp()
+  -- Create and set an active theme with components
+  local def = {
+    name = "Component Test Theme",
+    components = {
+      button = {
+        atlas = "path/to/button.png",
+      },
+      panel = {
+        atlas = "path/to/panel.png",
+      },
+    },
+  }
+  self.theme = Theme.new(def)
+  Theme.setActive(self.theme)
+end
+
+function TestThemeComponent:test_getComponent_returns_component()
+  local component = Theme.getComponent("button")
+  luaunit.assertNotNil(component)
+  luaunit.assertEquals(component.atlas, "path/to/button.png")
+end
+
+function TestThemeComponent:test_getComponent_returns_nil_for_nonexistent()
+  local component = Theme.getComponent("nonexistent")
+  luaunit.assertNil(component)
+end
+
+function TestThemeComponent:test_getComponent_with_state()
+  -- Add a component with states
+  local def = {
+    name = "State Test Theme",
+    components = {
+      button = {
+        atlas = "path/to/button.png",
+        states = {
+          hover = {
+            atlas = "path/to/button_hover.png",
+          },
+        },
+      },
+    },
+  }
+  local theme = Theme.new(def)
+  Theme.setActive(theme)
+
+  local component = Theme.getComponent("button", "hover")
+  luaunit.assertNotNil(component)
+  luaunit.assertEquals(component.atlas, "path/to/button_hover.png")
+end
+
+-- Test suite for Theme.getColor()
+TestThemeColor = {}
+
+function TestThemeColor:setUp()
+  local def = {
+    name = "Color Test Theme",
+    colors = {
+      primary = Color.new(1, 0, 0, 1),
+      secondary = Color.new(0, 1, 0, 1),
+      textColor = Color.new(0.5, 0.5, 0.5, 1),
+    },
+  }
+  self.theme = Theme.new(def)
+  Theme.setActive(self.theme)
+end
+
+function TestThemeColor:test_getColor_returns_color()
+  local color = Theme.getColor("primary")
+  luaunit.assertNotNil(color)
+  luaunit.assertEquals(color.r, 1)
+  luaunit.assertEquals(color.g, 0)
+  luaunit.assertEquals(color.b, 0)
+end
+
+function TestThemeColor:test_getColor_returns_nil_for_nonexistent()
+  local color = Theme.getColor("nonexistent")
+  luaunit.assertNil(color)
+end
+
+function TestThemeColor:test_getColorNames_returns_table()
+  local names = Theme.getColorNames()
+  luaunit.assertNotNil(names)
+  luaunit.assertEquals(type(names), "table")
+  -- Should contain our defined colors
+  luaunit.assertTrue(#names >= 3)
+end
+
+function TestThemeColor:test_getAllColors_returns_table()
+  local colors = Theme.getAllColors()
+  luaunit.assertNotNil(colors)
+  luaunit.assertEquals(type(colors), "table")
+  luaunit.assertNotNil(colors.primary)
+  luaunit.assertNotNil(colors.secondary)
+end
+
+function TestThemeColor:test_getColorOrDefault_returns_color()
+  local color = Theme.getColorOrDefault("primary", Color.new(0, 0, 0, 1))
+  luaunit.assertNotNil(color)
+  luaunit.assertEquals(color.r, 1)
+end
+
+function TestThemeColor:test_getColorOrDefault_returns_fallback()
+  local fallback = Color.new(0.1, 0.2, 0.3, 1)
+  local color = Theme.getColorOrDefault("nonexistent", fallback)
+  luaunit.assertNotNil(color)
+  luaunit.assertEquals(color.r, 0.1)
+  luaunit.assertEquals(color.g, 0.2)
+  luaunit.assertEquals(color.b, 0.3)
+end
+
+-- Test suite for Theme.getFont()
+TestThemeFont = {}
+
+function TestThemeFont:setUp()
+  local def = {
+    name = "Font Test Theme",
+    fonts = {
+      default = "path/to/default.ttf",
+      heading = "path/to/heading.ttf",
+    },
+  }
+  self.theme = Theme.new(def)
+  Theme.setActive(self.theme)
+end
+
+function TestThemeFont:test_getFont_returns_font_path()
+  local font = Theme.getFont("default")
+  luaunit.assertNotNil(font)
+  luaunit.assertEquals(font, "path/to/default.ttf")
+end
+
+function TestThemeFont:test_getFont_returns_nil_for_nonexistent()
+  local font = Theme.getFont("nonexistent")
+  luaunit.assertNil(font)
+end
+
+-- Run tests if this file is executed directly
+if not _G.RUNNING_ALL_TESTS then
+  os.exit(luaunit.LuaUnit.run())
+end

testing/__tests__/theme_validation_test.lua

@@ -37,7 +37,7 @@ end
 
 function TestThemeValidation:test_validate_minimal_valid_theme()
   local theme = {
-    name = "Test Theme"
+    name = "Test Theme",
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -46,7 +46,7 @@ end
 
 function TestThemeValidation:test_validate_theme_with_empty_name()
   local theme = {
-    name = ""
+    name = "",
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -55,7 +55,7 @@ end
 
 function TestThemeValidation:test_validate_theme_with_non_string_name()
   local theme = {
-    name = 123
+    name = 123,
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -69,8 +69,8 @@ function TestThemeValidation:test_validate_valid_colors()
     name = "Test Theme",
     colors = {
       primary = Color.new(1, 0, 0, 1),
-      secondary = Color.new(0, 1, 0, 1)
+      secondary = Color.new(0, 1, 0, 1),
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -81,8 +81,8 @@ function TestThemeValidation:test_validate_colors_with_hex()
   local theme = {
     name = "Test Theme",
     colors = {
-      primary = "#FF0000"
+      primary = "#FF0000",
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -94,8 +94,8 @@ function TestThemeValidation:test_validate_colors_with_named()
     name = "Test Theme",
     colors = {
       primary = "red",
-      secondary = "blue"
+      secondary = "blue",
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -106,8 +106,8 @@ function TestThemeValidation:test_validate_invalid_color()
   local theme = {
     name = "Test Theme",
     colors = {
-      primary = "not-a-color"
+      primary = "not-a-color",
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -118,7 +118,7 @@ end
 function TestThemeValidation:test_validate_colors_non_table()
   local theme = {
     name = "Test Theme",
-    colors = "should be a table"
+    colors = "should be a table",
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -129,8 +129,8 @@ function TestThemeValidation:test_validate_color_with_non_string_name()
   local theme = {
     name = "Test Theme",
     colors = {
-      [123] = Color.new(1, 0, 0, 1)
+      [123] = Color.new(1, 0, 0, 1),
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -144,8 +144,8 @@ function TestThemeValidation:test_validate_valid_fonts()
     name = "Test Theme",
     fonts = {
       default = "path/to/font.ttf",
-      heading = "path/to/heading.ttf"
+      heading = "path/to/heading.ttf",
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -155,7 +155,7 @@ end
 function TestThemeValidation:test_validate_fonts_non_table()
   local theme = {
     name = "Test Theme",
-    fonts = "should be a table"
+    fonts = "should be a table",
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -166,8 +166,8 @@ function TestThemeValidation:test_validate_font_with_non_string_path()
   local theme = {
     name = "Test Theme",
     fonts = {
-      default = 123
+      default = 123,
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -178,8 +178,8 @@ function TestThemeValidation:test_validate_font_with_non_string_name()
   local theme = {
     name = "Test Theme",
     fonts = {
-      [123] = "path/to/font.ttf"
+      [123] = "path/to/font.ttf",
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -193,9 +193,9 @@ function TestThemeValidation:test_validate_valid_component()
     name = "Test Theme",
     components = {
       button = {
-        atlas = "path/to/button.png"
+        atlas = "path/to/button.png",
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -208,9 +208,9 @@ function TestThemeValidation:test_validate_component_with_insets()
     components = {
       button = {
         atlas = "path/to/button.png",
-        insets = {left = 5, top = 5, right = 5, bottom = 5}
+        insets = { left = 5, top = 5, right = 5, bottom = 5 },
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -223,9 +223,9 @@ function TestThemeValidation:test_validate_component_with_missing_inset()
     components = {
       button = {
         atlas = "path/to/button.png",
-        insets = {left = 5, top = 5, right = 5} -- missing bottom
+        insets = { left = 5, top = 5, right = 5 }, -- missing bottom
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -239,9 +239,9 @@ function TestThemeValidation:test_validate_component_with_negative_inset()
     components = {
       button = {
         atlas = "path/to/button.png",
-        insets = {left = -5, top = 5, right = 5, bottom = 5}
+        insets = { left = -5, top = 5, right = 5, bottom = 5 },
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -257,14 +257,14 @@ function TestThemeValidation:test_validate_component_with_states()
         atlas = "path/to/button.png",
         states = {
           hover = {
-            atlas = "path/to/button_hover.png"
+            atlas = "path/to/button_hover.png",
           },
           pressed = {
-            atlas = "path/to/button_pressed.png"
+            atlas = "path/to/button_pressed.png",
-          }
+          },
-        }
+        },
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -278,10 +278,10 @@ function TestThemeValidation:test_validate_component_with_invalid_state()
       button = {
         atlas = "path/to/button.png",
         states = {
-          hover = "should be a table"
+          hover = "should be a table",
-        }
+        },
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -294,9 +294,9 @@ function TestThemeValidation:test_validate_component_with_scaleCorners()
     components = {
       button = {
         atlas = "path/to/button.png",
-        scaleCorners = 2.0
+        scaleCorners = 2.0,
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -309,9 +309,9 @@ function TestThemeValidation:test_validate_component_with_invalid_scaleCorners()
     components = {
       button = {
         atlas = "path/to/button.png",
-        scaleCorners = -1
+        scaleCorners = -1,
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -325,9 +325,9 @@ function TestThemeValidation:test_validate_component_with_valid_scalingAlgorithm
     components = {
       button = {
         atlas = "path/to/button.png",
-        scalingAlgorithm = "nearest"
+        scalingAlgorithm = "nearest",
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -340,9 +340,9 @@ function TestThemeValidation:test_validate_component_with_invalid_scalingAlgorit
     components = {
       button = {
         atlas = "path/to/button.png",
-        scalingAlgorithm = "invalid"
+        scalingAlgorithm = "invalid",
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -352,7 +352,7 @@ end
 function TestThemeValidation:test_validate_components_non_table()
   local theme = {
     name = "Test Theme",
-    components = "should be a table"
+    components = "should be a table",
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -364,7 +364,7 @@ end
 function TestThemeValidation:test_validate_valid_multiplier()
   local theme = {
     name = "Test Theme",
-    contentAutoSizingMultiplier = {width = 1.1, height = 1.2}
+    contentAutoSizingMultiplier = { width = 1.1, height = 1.2 },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -374,7 +374,7 @@ end
 function TestThemeValidation:test_validate_multiplier_with_only_width()
   local theme = {
     name = "Test Theme",
-    contentAutoSizingMultiplier = {width = 1.1}
+    contentAutoSizingMultiplier = { width = 1.1 },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -384,7 +384,7 @@ end
 function TestThemeValidation:test_validate_multiplier_non_table()
   local theme = {
     name = "Test Theme",
-    contentAutoSizingMultiplier = 1.5
+    contentAutoSizingMultiplier = 1.5,
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -394,7 +394,7 @@ end
 function TestThemeValidation:test_validate_multiplier_with_non_number()
   local theme = {
     name = "Test Theme",
-    contentAutoSizingMultiplier = {width = "not a number"}
+    contentAutoSizingMultiplier = { width = "not a number" },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -404,7 +404,7 @@ end
 function TestThemeValidation:test_validate_multiplier_with_negative()
   local theme = {
     name = "Test Theme",
-    contentAutoSizingMultiplier = {width = -1}
+    contentAutoSizingMultiplier = { width = -1 },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -415,7 +415,7 @@ end
 function TestThemeValidation:test_validate_multiplier_with_zero()
   local theme = {
     name = "Test Theme",
-    contentAutoSizingMultiplier = {width = 0}
+    contentAutoSizingMultiplier = { width = 0 },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)
@@ -427,7 +427,7 @@ end
 function TestThemeValidation:test_validate_valid_global_atlas()
   local theme = {
     name = "Test Theme",
-    atlas = "path/to/atlas.png"
+    atlas = "path/to/atlas.png",
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -439,7 +439,7 @@ end
 function TestThemeValidation:test_validate_unknown_field_strict()
   local theme = {
     name = "Test Theme",
-    unknownField = "should trigger warning"
+    unknownField = "should trigger warning",
   }
   local valid, errors = Theme.validateTheme(theme, { strict = true })
   luaunit.assertFalse(valid)
@@ -450,7 +450,7 @@ end
 function TestThemeValidation:test_validate_unknown_field_non_strict()
   local theme = {
     name = "Test Theme",
-    unknownField = "should be ignored"
+    unknownField = "should be ignored",
   }
   local valid, errors = Theme.validateTheme(theme, { strict = false })
   luaunit.assertTrue(valid)
@@ -467,7 +467,7 @@ end
 
 function TestThemeValidation:test_sanitize_theme_without_name()
   local theme = {
-    colors = {primary = "red"}
+    colors = { primary = "red" },
   }
   local sanitized = Theme.sanitizeTheme(theme)
   luaunit.assertEquals(sanitized.name, "Unnamed Theme")
@@ -475,7 +475,7 @@ end
 
 function TestThemeValidation:test_sanitize_theme_with_non_string_name()
   local theme = {
-    name = 123
+    name = 123,
   }
   local sanitized = Theme.sanitizeTheme(theme)
   luaunit.assertEquals(type(sanitized.name), "string")
@@ -486,8 +486,8 @@ function TestThemeValidation:test_sanitize_colors()
     name = "Test",
     colors = {
       valid = "red",
-      invalid = "not-a-color"
+      invalid = "not-a-color",
-    }
+    },
   }
   local sanitized = Theme.sanitizeTheme(theme)
   luaunit.assertNotNil(sanitized.colors.valid)
@@ -498,8 +498,8 @@ function TestThemeValidation:test_sanitize_removes_non_string_color_names()
   local theme = {
     name = "Test",
     colors = {
-      [123] = "red"
+      [123] = "red",
-    }
+    },
   }
   local sanitized = Theme.sanitizeTheme(theme)
   luaunit.assertNil(sanitized.colors[123])
@@ -510,8 +510,8 @@ function TestThemeValidation:test_sanitize_fonts()
     name = "Test",
     fonts = {
       default = "path/to/font.ttf",
-      invalid = 123
+      invalid = 123,
-    }
+    },
   }
   local sanitized = Theme.sanitizeTheme(theme)
   luaunit.assertNotNil(sanitized.fonts.default)
@@ -522,8 +522,8 @@ function TestThemeValidation:test_sanitize_preserves_components()
   local theme = {
     name = "Test",
     components = {
-      button = {atlas = "path/to/button.png"}
+      button = { atlas = "path/to/button.png" },
-    }
+    },
   }
   local sanitized = Theme.sanitizeTheme(theme)
   luaunit.assertNotNil(sanitized.components.button)
@@ -540,11 +540,11 @@ function TestThemeValidation:test_validate_complete_theme()
     colors = {
       primary = Color.new(1, 0, 0, 1),
       secondary = "#00FF00",
-      tertiary = "blue"
+      tertiary = "blue",
     },
     fonts = {
       default = "path/to/font.ttf",
-      heading = "path/to/heading.ttf"
+      heading = "path/to/heading.ttf",
     },
     components = {
       button = {
@@ -554,17 +554,17 @@ function TestThemeValidation:test_validate_complete_theme()
         scalingAlgorithm = "nearest",
         states = {
           hover = {
-            atlas = "path/to/button_hover.png"
+            atlas = "path/to/button_hover.png",
           },
           pressed = {
-            atlas = "path/to/button_pressed.png"
+            atlas = "path/to/button_pressed.png",
-          }
+          },
-        }
+        },
       },
       panel = {
-        atlas = "path/to/panel.png"
+        atlas = "path/to/panel.png",
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertTrue(valid)
@@ -576,16 +576,16 @@ function TestThemeValidation:test_validate_theme_with_multiple_errors()
     name = "",
     colors = {
       invalid1 = "not-a-color",
-      invalid2 = 123
+      invalid2 = 123,
     },
     fonts = {
-      bad = 456
+      bad = 456,
     },
     components = {
       button = {
-        insets = {left = -5} -- missing fields and negative
+        insets = { left = -5 }, -- missing fields and negative
-      }
+      },
-    }
+    },
   }
   local valid, errors = Theme.validateTheme(theme)
   luaunit.assertFalse(valid)

testing/__tests__/units_test.lua

@@ -251,7 +251,7 @@ function TestUnitsResolveSpacing:testResolveSpacingAllSides()
     top = "10px",
     right = "20px",
     bottom = "30px",
-    left = "40px"
+    left = "40px",
   }
   local result = Units.resolveSpacing(spacing, 800, 600)
   luaunit.assertEquals(result.top, 10)
@@ -263,7 +263,7 @@ end
 function TestUnitsResolveSpacing:testResolveSpacingVerticalHorizontal()
   local spacing = {
     vertical = "10px",
-    horizontal = "20px"
+    horizontal = "20px",
   }
   local result = Units.resolveSpacing(spacing, 800, 600)
   luaunit.assertEquals(result.top, 10)
@@ -275,7 +275,7 @@ end
 function TestUnitsResolveSpacing:testResolveSpacingVerticalHorizontalNumbers()
   local spacing = {
     vertical = 10,
-    horizontal = 20
+    horizontal = 20,
   }
   local result = Units.resolveSpacing(spacing, 800, 600)
   luaunit.assertEquals(result.top, 10)
@@ -289,7 +289,7 @@ function TestUnitsResolveSpacing:testResolveSpacingMixedPercentage()
     top = "10%",
     right = "5%",
     bottom = "10%",
-    left = "5%"
+    left = "5%",
   }
   local result = Units.resolveSpacing(spacing, 800, 600)
   luaunit.assertEquals(result.top, 60) -- 10% of 600 (height)
@@ -303,7 +303,7 @@ function TestUnitsResolveSpacing:testResolveSpacingOverride()
   local spacing = {
     vertical = "10px",
     horizontal = "20px",
-    top = "50px"
+    top = "50px",
   }
   local result = Units.resolveSpacing(spacing, 800, 600)
   luaunit.assertEquals(result.top, 50) -- Overridden

testing/__tests__/utils_test.lua

@@ -286,10 +286,10 @@ function TestFontUtils:testResolveFontPath_ThemeFont()
     getTheme = function()
       return {
         fonts = {
-          mainFont = "themes/fonts/main.ttf"
+          mainFont = "themes/fonts/main.ttf",
+        },
       }
-      }
+    end,
-    end
   }
 
   local result = utils.resolveFontPath("mainFont", "button", mockThemeManager)
@@ -301,9 +301,9 @@ function TestFontUtils:testResolveFontPath_ThemeFontNotFound()
   local mockThemeManager = {
     getTheme = function()
       return {
-        fonts = {}
+        fonts = {},
       }
-    end
+    end,
   }
 
   -- Should fall back to treating it as a direct path

testing/runAll.lua

@@ -26,7 +26,10 @@ local testFiles = {
   "testing/__tests__/color_validation_test.lua",
   "testing/__tests__/texteditor_sanitization_test.lua",
   "testing/__tests__/theme_validation_test.lua",
+  "testing/__tests__/theme_core_test.lua",
   "testing/__tests__/units_test.lua",
+  "testing/__tests__/layout_engine_test.lua",
+  "testing/__tests__/element_test.lua",
 }
 
 local success = true