Fix Dart LSP definition lookup and add comprehensive tests

Fixed Dart LSP definition lookup issues:
- Handle Dart's function/method naming convention (returns names with parentheses)
- Support qualified names like ClassName.methodName
- Extract definition text directly from workspace/symbol location
- Update hover test snapshot for comment change

Added comprehensive test coverage with 23 test cases covering classes,
functions, methods, enums, mixins, extensions, and typedefs.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

integrationtests/snapshots/dart/definition/constant.snap

@@ -0,0 +1,10 @@
+---
+
+Symbol: SHARED_CONSTANT
+/TEST_OUTPUT/workspace/types.dart
+Kind: Variable
+Range: L29:C1 - L30:C46
+
+29|/// A constant value
+30|const String SHARED_CONSTANT = 'shared_value'
+

integrationtests/snapshots/dart/definition/enum.snap

@@ -0,0 +1,14 @@
+---
+
+Symbol: Color
+/TEST_OUTPUT/workspace/types.dart
+Kind: Enum
+Range: L32:C1 - L37:C2
+
+32|/// An enum for testing
+33|enum Color {
+34|  red,
+35|  green, 
+36|  blue
+37|}
+

integrationtests/snapshots/dart/definition/global-function.snap

@@ -0,0 +1,12 @@
+---
+
+Symbol: createHelper(…)
+/TEST_OUTPUT/workspace/helper.dart
+Kind: Function
+Range: L24:C1 - L27:C2
+
+24|/// A helper function that creates instances
+25|HelperClass createHelper(String name) {
+26|  return HelperClass(name);
+27|}
+

integrationtests/snapshots/dart/definition/global-variable.snap

@@ -0,0 +1,10 @@
+---
+
+Symbol: globalHelper
+/TEST_OUTPUT/workspace/helper.dart
+Kind: Variable
+Range: L29:C1 - L30:C43
+
+29|/// Global variable for testing
+30|final globalHelper = HelperClass('global')
+

integrationtests/snapshots/dart/definition/local-class.snap

@@ -0,0 +1,28 @@
+---
+
+Symbol: HelperClass
+/TEST_OUTPUT/workspace/helper.dart
+Kind: Class
+Range: L3:C1 - L22:C2
+
+ 3|/// Helper class for demonstration
+ 4|class HelperClass implements SharedInterface {
+ 5|  final String name;
+ 6|  
+ 7|  HelperClass(this.name);
+ 8|  
+ 9|  @override
+10|  void doSomething() {
+11|    print('Doing something with $name');
+12|  }
+13|  
+14|  @override
+15|  String getName() => name;
+16|  
+17|  /// Process method specific to HelperClass
+18|  void process() {
+19|    doSomething();
+20|    print('Processing: ${getName()}');
+21|  }
+22|}
+

integrationtests/snapshots/dart/definition/main-function.snap

@@ -0,0 +1,73 @@
+---
+
+Symbol: main()
+/TEST_OUTPUT/workspace/main.dart
+Kind: Function
+Range: L5:C1 - L24:C2
+
+ 5|void main() {
+ 6|  print('Hello, World!');
+ 7|
+ 8|  var helper = HelperClass('test');
+ 9|  helper.process();
+10|
+11|  SharedClass shared = SharedClass(42);
+12|  print(shared.getValue());
+13|
+14|  // Use types
+15|  Color color = Color.red;
+16|  print(color);
+17|
+18|  // Use constant
+19|  print(SHARED_CONSTANT);
+20|
+21|  // Use function
+22|  var newHelper = createHelper('new');
+23|  print(newHelper.getName());
+24|}
+
+---
+
+Symbol: main()
+File: /DART_SDK/lib/_internal/vm/bin/vmservice_io.dart
+Kind: Function
+Range: L273:C1 - L309:C2
+
+273|@pragma('vm:entry-point', !bool.fromEnvironment('dart.vm.product'))
+274|void main() {
+275|  // Set embedder hooks.
+276|  VMServiceEmbedderHooks.cleanup = cleanupCallback;
+277|  VMServiceEmbedderHooks.createTempDir = createTempDirCallback;
+278|  VMServiceEmbedderHooks.ddsConnected = ddsConnectedCallback;
+279|  VMServiceEmbedderHooks.ddsDisconnected = ddsDisconnectedCallback;
+280|  VMServiceEmbedderHooks.deleteDir = deleteDirCallback;
+281|  VMServiceEmbedderHooks.writeFile = writeFileCallback;
+282|  VMServiceEmbedderHooks.writeStreamFile = writeStreamFileCallback;
+283|  VMServiceEmbedderHooks.readFile = readFileCallback;
+284|  VMServiceEmbedderHooks.listFiles = listFilesCallback;
+285|  VMServiceEmbedderHooks.serverInformation = serverInformationCallback;
+286|  VMServiceEmbedderHooks.webServerControl = webServerControlCallback;
+287|  VMServiceEmbedderHooks.acceptNewWebSocketConnections =
+288|      webServerAcceptNewWebSocketConnections;
+289|  VMServiceEmbedderHooks.serveObservatory = serveObservatoryCallback;
+290|  VMServiceEmbedderHooks.getResidentCompilerInfoFile =
+291|      _getResidentCompilerInfoFile;
+292|
+293|  server = Server(
+294|    // Always instantiate the vmservice object so that the exit message
+295|    // can be delivered and waiting loaders can be cancelled.
+296|    VMService(),
+297|    _ip,
+298|    _port,
+299|    _originCheckDisabled,
+300|    _authCodesDisabled,
+301|    _serviceInfoFilename,
+302|    _enableServicePortFallback,
+303|  );
+304|
+305|  if (_autoStart) {
+306|    _toggleWebServer();
+307|  }
+308|  _registerSignalHandler();
+309|}
+

integrationtests/snapshots/dart/definition/method-qualified.snap

@@ -0,0 +1,14 @@
+---
+
+Symbol: process()
+/TEST_OUTPUT/workspace/helper.dart
+Kind: Method
+Container Name: HelperClass
+Range: L17:C3 - L21:C4
+
+17|/// Process method specific to HelperClass
+18|  void process() {
+19|    doSomething();
+20|    print('Processing: ${getName()}');
+21|  }
+

integrationtests/snapshots/dart/definition/method-simple.snap

@@ -0,0 +1,107 @@
+---
+
+Symbol: process
+File: /DART_SDK/lib/io/io_resource_info.dart
+Kind: Field
+Container Name: _SpawnedProcessResourceInfo
+Range: L146:C3 - L146:C25
+
+146|final _Process process
+
+---
+
+Symbol: process
+File: /PUB_CACHE/hosted/pub.dev/test_core-0.6.12/lib/src/runner/vm/test_compiler.dart
+Kind: Enum
+Range: L246:C1 - L246:C35
+
+246|enum VmTestType { isolate, process }
+
+---
+
+Symbol: process()
+/TEST_OUTPUT/workspace/helper.dart
+Kind: Method
+Container Name: HelperClass
+Range: L17:C3 - L21:C4
+
+17|/// Process method specific to HelperClass
+18|  void process() {
+19|    doSomething();
+20|    print('Processing: ${getName()}');
+21|  }
+
+---
+
+Symbol: process()
+/TEST_OUTPUT/workspace/types.dart
+Kind: Method
+Container Name: SharedClass
+Range: L14:C3 - L17:C4
+
+14|/// A method that processes the value
+15|  String process() {
+16|    return 'Processed: $value';
+17|  }
+
+---
+
+Symbol: process()
+File: /DART_SDK/lib/ffi/dynamic_library.dart
+Kind: Constructor
+Container Name: DynamicLibrary
+Range: L12:C3 - L16:C45
+
+12|/// Creates a [DynamicLibrary] holding all global symbols.
+13|  ///
+14|  /// Any symbol in a library currently loaded with global visibility
+15|  /// (including the executable itself) may be resolved through this library.
+16|  external factory DynamicLibrary.process();
+
+---
+
+Symbol: process(…)
+File: /DART_SDK/lib/io/data_transformer.dart
+Kind: Method
+Container Name: RawZLibFilter
+Range: L436:C3 - L439:C52
+
+436|/// Process a chunk of data.
+437|  ///
+438|  /// This method must only be called when [processed] returns `null`.
+439|  void process(List<int> data, int start, int end);
+
+---
+
+Symbol: process(…)
+File: /PUB_CACHE/hosted/pub.dev/analyzer-8.1.0/lib/src/dart/element/replace_top_bottom_visitor.dart
+Kind: Method
+Container Name: ReplaceTopBottomVisitor
+Range: L20:C3 - L44:C4
+
+20|TypeImpl process(TypeImpl type, Variance variance) {
+21|    if (variance.isContravariant) {
+22|      // ...replacing every occurrence in `T` of a type `S` in a contravariant
+23|      // position where `S <: Never` by `Object?`
+24|      if (_typeSystem.isSubtypeOf(type, NeverTypeImpl.instance)) {
+25|        return _topType;
+26|      }
+27|    } else {
+28|      // ...and every occurrence in `T` of a top type in a position which
+29|      // is not contravariant by `Never`.
+30|      if (_typeSystem.isTop(type)) {
+31|        return _bottomType;
+32|      }
+33|    }
+34|
+35|    var alias = type.alias;
+36|    if (alias != null) {
+37|      return _instantiatedTypeAlias(type, alias, variance);
+38|    } else if (type is InterfaceTypeImpl) {
+39|      return _interfaceType(type, variance);
+40|    } else if (type is FunctionTypeImpl) {
+41|      return _functionType(type, variance);
+42|    }
+43|    return type;
+44|  }
+

integrationtests/snapshots/dart/definition/nonexistent-symbol.snap

@@ -0,0 +1 @@
+NonExistentSymbol not found

integrationtests/snapshots/dart/definition/query-enum-value.snap

@@ -0,0 +1,14 @@
+---
+
+Symbol: Color
+/TEST_OUTPUT/workspace/types.dart
+Kind: Enum
+Range: L32:C1 - L37:C2
+
+32|/// An enum for testing
+33|enum Color {
+34|  red,
+35|  green, 
+36|  blue
+37|}
+

integrationtests/snapshots/dart/definition/query-exact-match.snap

@@ -0,0 +1,28 @@
+---
+
+Symbol: HelperClass
+/TEST_OUTPUT/workspace/helper.dart
+Kind: Class
+Range: L3:C1 - L22:C2
+
+ 3|/// Helper class for demonstration
+ 4|class HelperClass implements SharedInterface {
+ 5|  final String name;
+ 6|  
+ 7|  HelperClass(this.name);
+ 8|  
+ 9|  @override
+10|  void doSomething() {
+11|    print('Doing something with $name');
+12|  }
+13|  
+14|  @override
+15|  String getName() => name;
+16|  
+17|  /// Process method specific to HelperClass
+18|  void process() {
+19|    doSomething();
+20|    print('Processing: ${getName()}');
+21|  }
+22|}
+

integrationtests/snapshots/dart/definition/query-lowercase.snap

@@ -0,0 +1 @@
+helperclass not found

integrationtests/snapshots/dart/definition/query-main.snap

@@ -0,0 +1,73 @@
+---
+
+Symbol: main()
+/TEST_OUTPUT/workspace/main.dart
+Kind: Function
+Range: L5:C1 - L24:C2
+
+ 5|void main() {
+ 6|  print('Hello, World!');
+ 7|
+ 8|  var helper = HelperClass('test');
+ 9|  helper.process();
+10|
+11|  SharedClass shared = SharedClass(42);
+12|  print(shared.getValue());
+13|
+14|  // Use types
+15|  Color color = Color.red;
+16|  print(color);
+17|
+18|  // Use constant
+19|  print(SHARED_CONSTANT);
+20|
+21|  // Use function
+22|  var newHelper = createHelper('new');
+23|  print(newHelper.getName());
+24|}
+
+---
+
+Symbol: main()
+File: /DART_SDK/lib/_internal/vm/bin/vmservice_io.dart
+Kind: Function
+Range: L273:C1 - L309:C2
+
+273|@pragma('vm:entry-point', !bool.fromEnvironment('dart.vm.product'))
+274|void main() {
+275|  // Set embedder hooks.
+276|  VMServiceEmbedderHooks.cleanup = cleanupCallback;
+277|  VMServiceEmbedderHooks.createTempDir = createTempDirCallback;
+278|  VMServiceEmbedderHooks.ddsConnected = ddsConnectedCallback;
+279|  VMServiceEmbedderHooks.ddsDisconnected = ddsDisconnectedCallback;
+280|  VMServiceEmbedderHooks.deleteDir = deleteDirCallback;
+281|  VMServiceEmbedderHooks.writeFile = writeFileCallback;
+282|  VMServiceEmbedderHooks.writeStreamFile = writeStreamFileCallback;
+283|  VMServiceEmbedderHooks.readFile = readFileCallback;
+284|  VMServiceEmbedderHooks.listFiles = listFilesCallback;
+285|  VMServiceEmbedderHooks.serverInformation = serverInformationCallback;
+286|  VMServiceEmbedderHooks.webServerControl = webServerControlCallback;
+287|  VMServiceEmbedderHooks.acceptNewWebSocketConnections =
+288|      webServerAcceptNewWebSocketConnections;
+289|  VMServiceEmbedderHooks.serveObservatory = serveObservatoryCallback;
+290|  VMServiceEmbedderHooks.getResidentCompilerInfoFile =
+291|      _getResidentCompilerInfoFile;
+292|
+293|  server = Server(
+294|    // Always instantiate the vmservice object so that the exit message
+295|    // can be delivered and waiting loaders can be cancelled.
+296|    VMService(),
+297|    _ip,
+298|    _port,
+299|    _originCheckDisabled,
+300|    _authCodesDisabled,
+301|    _serviceInfoFilename,
+302|    _enableServicePortFallback,
+303|  );
+304|
+305|  if (_autoStart) {
+306|    _toggleWebServer();
+307|  }
+308|  _registerSignalHandler();
+309|}
+