Add unit tests for DartCodeFoldingSettings

third_party/src/test/java/com/jetbrains/lang/dart/folding/DartCodeFoldingSettingsTest.java

@@ -0,0 +1,72 @@
+package com.jetbrains.lang.dart.folding;
+
+import com.intellij.testFramework.fixtures.BasePlatformTestCase;
+
+public class DartCodeFoldingSettingsTest extends BasePlatformTestCase {
+
+  public void testGetInstance() {
+    DartCodeFoldingSettings settings = DartCodeFoldingSettings.getInstance();
+    assertNotNull("DartCodeFoldingSettings instance should not be null", settings);
+  }
+
+  public void testDefaultValues() {
+    DartCodeFoldingSettings settings = new DartCodeFoldingSettings();
+    assertTrue("Collapse parts should be true by default", settings.isCollapseParts());
+    assertFalse("Collapse generic parameters should be false by default", settings.isCollapseGenericParameters());
+  }
+
+  public void testCollapseParts() {
+    DartCodeFoldingSettings settings = new DartCodeFoldingSettings();
+
+    // Initial check
+    assertTrue(settings.isCollapseParts());
+
+    // Set to false
+    settings.setCollapseParts(false);
+    assertFalse("Collapse parts should be false after setting", settings.isCollapseParts());
+
+    // Set back to true
+    settings.setCollapseParts(true);
+    assertTrue("Collapse parts should be true after setting", settings.isCollapseParts());
+  }
+
+  public void testCollapseGenericParameters() {
+    DartCodeFoldingSettings settings = new DartCodeFoldingSettings();
+
+    // Initial check
+    assertFalse(settings.isCollapseGenericParameters());
+
+    // Set to true
+    settings.setCollapseGenericParameters(true);
+    assertTrue("Collapse generic parameters should be true after setting", settings.isCollapseGenericParameters());
+
+    // Set back to false
+    settings.setCollapseGenericParameters(false);
+    assertFalse("Collapse generic parameters should be false after setting", settings.isCollapseGenericParameters());
+  }
+
+  public void testGetState() {
+    DartCodeFoldingSettings settings = new DartCodeFoldingSettings();
+    assertSame("getState() should return the instance itself", settings, settings.getState());
+  }
+
+  public void testLoadState() {
+    DartCodeFoldingSettings targetSettings = new DartCodeFoldingSettings();
+    DartCodeFoldingSettings sourceSettings = new DartCodeFoldingSettings();
+
+    // Configure source settings
+    sourceSettings.setCollapseParts(false);
+    sourceSettings.setCollapseGenericParameters(true);
+
+    // Load state
+    targetSettings.loadState(sourceSettings);
+
+    // Verify target settings match source
+    assertFalse("Collapse parts should be loaded as false", targetSettings.isCollapseParts());
+    assertTrue("Collapse generic parameters should be loaded as true", targetSettings.isCollapseGenericParameters());
+
+    // Verify independent modification
+    sourceSettings.setCollapseParts(true);
+    assertFalse("Target settings should remain unchanged", targetSettings.isCollapseParts());
+  }
+}