LS: mark LS that support implementation request

src/solidlsp/language_servers/csharp_language_server.py

@@ -206,6 +206,10 @@ class CSharpLanguageServer(SolidLanguageServer):
     scripts. If you have a custom .NET installation, ensure 'dotnet' is available in PATH with version 10 or higher.
     """
 
+    @classmethod
+    def supports_implementation_request(cls) -> bool:
+        return True
+
     def __init__(self, config: LanguageServerConfig, repository_root_path: str, solidlsp_settings: SolidLSPSettings):
         """
         Creates a CSharpLanguageServer instance. This class is not meant to be instantiated directly.

src/solidlsp/language_servers/eclipse_jdtls.py

@@ -152,6 +152,10 @@ class EclipseJDTLS(SolidLanguageServer):
     ```
     """
 
+    @classmethod
+    def supports_implementation_request(cls) -> bool:
+        return True
+
     def __init__(self, config: LanguageServerConfig, repository_root_path: str, solidlsp_settings: SolidLSPSettings):
         """
         Creates a new EclipseJDTLS instance initializing the language server settings appropriately.

src/solidlsp/language_servers/gopls.py

@@ -23,6 +23,10 @@ class Gopls(SolidLanguageServer):
     Provides Go specific instantiation of the LanguageServer class using gopls.
     """
 
+    @classmethod
+    def supports_implementation_request(cls) -> bool:
+        return True
+
     @override
     def is_ignored_dirname(self, dirname: str) -> bool:
         # For Go projects, we should ignore:

src/solidlsp/language_servers/rust_analyzer.py

@@ -26,6 +26,10 @@ class RustAnalyzer(SolidLanguageServer):
     Provides Rust specific instantiation of the LanguageServer class. Contains various configurations and settings specific to Rust.
     """
 
+    @classmethod
+    def supports_implementation_request(cls) -> bool:
+        return True
+
     @staticmethod
     def _determine_log_level(line: str) -> int:
         """Classify rust-analyzer stderr output to avoid false-positive errors."""

src/solidlsp/language_servers/typescript_language_server.py

@@ -67,6 +67,10 @@ class TypeScriptLanguageServer(SolidLanguageServer):
         - typescript_language_server_version: Version of typescript-language-server to install (default: "5.1.3")
     """
 
+    @classmethod
+    def supports_implementation_request(cls) -> bool:
+        return True
+
     # Safety timeout for $/progress-based indexing wait. Normally the event fires
     # well within this window; the timeout is only hit if the server never sends progress.
     INDEXING_PROGRESS_TIMEOUT = 15.0 if os.name == "nt" else 10.0

src/solidlsp/ls_config.py

@@ -207,6 +207,12 @@ class Language(str, Enum):
             case _:
                 return 2
 
+    def supports_implementation_request(self) -> bool:
+        """
+        Return whether the default language server for this language supports ``textDocument/implementation``.
+        """
+        return self.get_ls_class().supports_implementation_request()
+
     def get_source_fn_matcher(self) -> FilenameMatcher:
         match self:
             case self.PYTHON | self.PYTHON_JEDI | self.PYTHON_TY: