test(ui): add comprehensive tests for UI Editor components

Add 22 new test files covering all UI Editor components:
- Button: JButton, JButtonGroup, JIconButton, JToggleButton
- Form: JDropdown, JFormField, JObjectField, JTextField, JToggle
- Layout: JCard, JRow, JSection, JStack
- Feedback: JLogView, JProgressBar, JStatusBar
- Navigation: JBreadcrumb
- Theming: JTheme, Tokens
- Utilities: EnumHelpers, StyleSheetManager
- Base: JComponent

Coverage improved from 14% to 61.7% for UI.Editor package.
Uses reflection for button click testing with graceful fallback.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: JasonXuDeveloper

UnityProject/Packages/com.jasonxudeveloper.jengine.ui/Tests/Editor/Components.meta

@@ -0,0 +1,284 @@
+// JComponentTests.cs
+// EditMode unit tests for JComponent base class
+
+using NUnit.Framework;
+using UnityEngine.UIElements;
+using JEngine.UI.Editor.Components;
+using JEngine.UI.Editor.Components.Layout;
+
+namespace JEngine.UI.Tests.Editor.Components.Base
+{
+    [TestFixture]
+    public class JComponentTests
+    {
+        // Using JStack as concrete implementation of JComponent
+        private JStack _component;
+
+        [SetUp]
+        public void SetUp()
+        {
+            _component = new JStack();
+        }
+
+        #region Constructor Tests
+
+        [Test]
+        public void Constructor_WithBaseClassName_AddsClass()
+        {
+            // JStack inherits from JComponent with "j-stack" as base class
+            Assert.IsTrue(_component.ClassListContains("j-stack"));
+        }
+
+        #endregion
+
+        #region WithClass Tests
+
+        [Test]
+        public void WithClass_AddsClassName()
+        {
+            _component.WithClass("custom-class");
+            Assert.IsTrue(_component.ClassListContains("custom-class"));
+        }
+
+        [Test]
+        public void WithClass_ReturnsComponentForChaining()
+        {
+            var result = _component.WithClass("test");
+            Assert.AreSame(_component, result);
+        }
+
+        [Test]
+        public void WithClass_CanAddMultipleClasses()
+        {
+            _component.WithClass("class1");
+            _component.WithClass("class2");
+
+            Assert.IsTrue(_component.ClassListContains("class1"));
+            Assert.IsTrue(_component.ClassListContains("class2"));
+        }
+
+        #endregion
+
+        #region WithName Tests
+
+        [Test]
+        public void WithName_SetsElementName()
+        {
+            _component.WithName("test-element");
+            Assert.AreEqual("test-element", _component.name);
+        }
+
+        [Test]
+        public void WithName_ReturnsComponentForChaining()
+        {
+            var result = _component.WithName("test");
+            Assert.AreSame(_component, result);
+        }
+
+        [Test]
+        public void WithName_CanOverwritePreviousName()
+        {
+            _component.WithName("first");
+            _component.WithName("second");
+            Assert.AreEqual("second", _component.name);
+        }
+
+        #endregion
+
+        #region Add Tests
+
+        [Test]
+        public void Add_SingleChild_AddsToComponent()
+        {
+            var child = new Label("test");
+            _component.Add(child);
+
+            Assert.AreEqual(1, _component.childCount);
+            Assert.AreSame(child, _component[0]);
+        }
+
+        [Test]
+        public void Add_MultipleChildren_AddsAllToComponent()
+        {
+            var child1 = new Label("test1");
+            var child2 = new Label("test2");
+            var child3 = new Label("test3");
+
+            _component.Add(child1, child2, child3);
+
+            Assert.AreEqual(3, _component.childCount);
+        }
+
+        [Test]
+        public void Add_NullChild_IsIgnored()
+        {
+            _component.Add((VisualElement)null);
+            Assert.AreEqual(0, _component.childCount);
+        }
+
+        [Test]
+        public void Add_MixedNullAndValid_AddsOnlyValidChildren()
+        {
+            var child1 = new Label("test1");
+            var child2 = new Label("test2");
+
+            _component.Add(child1, null, child2);
+
+            Assert.AreEqual(2, _component.childCount);
+        }
+
+        [Test]
+        public void Add_ReturnsComponentForChaining()
+        {
+            var result = _component.Add(new Label());
+            Assert.AreSame(_component, result);
+        }
+
+        #endregion
+
+        #region WithFlexGrow Tests
+
+        [Test]
+        public void WithFlexGrow_SetsFlexGrowValue()
+        {
+            _component.WithFlexGrow(2f);
+            Assert.AreEqual(2f, _component.style.flexGrow.value);
+        }
+
+        [Test]
+        public void WithFlexGrow_ReturnsComponentForChaining()
+        {
+            var result = _component.WithFlexGrow(1f);
+            Assert.AreSame(_component, result);
+        }
+
+        [Test]
+        public void WithFlexGrow_ZeroValue_SetsToZero()
+        {
+            _component.WithFlexGrow(0f);
+            Assert.AreEqual(0f, _component.style.flexGrow.value);
+        }
+
+        #endregion
+
+        #region WithFlexShrink Tests
+
+        [Test]
+        public void WithFlexShrink_SetsFlexShrinkValue()
+        {
+            _component.WithFlexShrink(2f);
+            Assert.AreEqual(2f, _component.style.flexShrink.value);
+        }
+
+        [Test]
+        public void WithFlexShrink_ReturnsComponentForChaining()
+        {
+            var result = _component.WithFlexShrink(1f);
+            Assert.AreSame(_component, result);
+        }
+
+        #endregion
+
+        #region WithMargin Tests
+
+        [Test]
+        public void WithMargin_SetsAllMargins()
+        {
+            _component.WithMargin(10f);
+
+            Assert.AreEqual(10f, _component.style.marginTop.value.value);
+            Assert.AreEqual(10f, _component.style.marginRight.value.value);
+            Assert.AreEqual(10f, _component.style.marginBottom.value.value);
+            Assert.AreEqual(10f, _component.style.marginLeft.value.value);
+        }
+
+        [Test]
+        public void WithMargin_ReturnsComponentForChaining()
+        {
+            var result = _component.WithMargin(5f);
+            Assert.AreSame(_component, result);
+        }
+
+        #endregion
+
+        #region WithPadding Tests
+
+        [Test]
+        public void WithPadding_SetsAllPadding()
+        {
+            _component.WithPadding(10f);
+
+            Assert.AreEqual(10f, _component.style.paddingTop.value.value);
+            Assert.AreEqual(10f, _component.style.paddingRight.value.value);
+            Assert.AreEqual(10f, _component.style.paddingBottom.value.value);
+            Assert.AreEqual(10f, _component.style.paddingLeft.value.value);
+        }
+
+        [Test]
+        public void WithPadding_ReturnsComponentForChaining()
+        {
+            var result = _component.WithPadding(5f);
+            Assert.AreSame(_component, result);
+        }
+
+        #endregion
+
+        #region WithVisibility Tests
+
+        [Test]
+        public void WithVisibility_True_SetsDisplayFlex()
+        {
+            _component.WithVisibility(true);
+            Assert.AreEqual(DisplayStyle.Flex, _component.style.display.value);
+        }
+
+        [Test]
+        public void WithVisibility_False_SetsDisplayNone()
+        {
+            _component.WithVisibility(false);
+            Assert.AreEqual(DisplayStyle.None, _component.style.display.value);
+        }
+
+        [Test]
+        public void WithVisibility_ReturnsComponentForChaining()
+        {
+            var result = _component.WithVisibility(true);
+            Assert.AreSame(_component, result);
+        }
+
+        [Test]
+        public void WithVisibility_CanToggle()
+        {
+            _component.WithVisibility(false);
+            Assert.AreEqual(DisplayStyle.None, _component.style.display.value);
+
+            _component.WithVisibility(true);
+            Assert.AreEqual(DisplayStyle.Flex, _component.style.display.value);
+        }
+
+        #endregion
+
+        #region Chaining Tests
+
+        [Test]
+        public void FluentApi_CanChainMultipleMethods()
+        {
+            _component
+                .WithName("test")
+                .WithClass("custom")
+                .WithMargin(5f)
+                .WithPadding(10f)
+                .WithFlexGrow(1f)
+                .WithVisibility(true);
+
+            Assert.AreEqual("test", _component.name);
+            Assert.IsTrue(_component.ClassListContains("custom"));
+            Assert.AreEqual(5f, _component.style.marginTop.value.value);
+            Assert.AreEqual(10f, _component.style.paddingTop.value.value);
+            Assert.AreEqual(1f, _component.style.flexGrow.value);
+            Assert.AreEqual(DisplayStyle.Flex, _component.style.display.value);
+        }
+
+        #endregion
+    }
+}