lsp: Allow features to register shutdown handlers

lib/esbonio/esbonio/server/feature.py

@@ -57,6 +57,9 @@ def initialize(self, params: types.InitializeParams):
     def initialized(self, params: types.InitializedParams):
         """Called when the ``initialized`` notification is received."""
 
+    def shutdown(self, params: None):
+        """Called when the server is instructed to ``shutdown`` by the client."""
+
     def document_change(self, params: types.DidChangeTextDocumentParams):
         """Called when a text document is changed."""
 

lib/esbonio/esbonio/server/server.py

@@ -123,6 +123,9 @@ async def initialized(self, params: types.InitializedParams):
         )
         self._ready.set_result(True)
 
+    def lsp_shutdown(self, params: None):
+        """Called when the server is instructed to ``shutdown`` by the client."""
+
     def load_extension(self, name: str, setup: Callable):
         """Load the given setup function as an extension.
 

lib/esbonio/esbonio/server/setup.py

@@ -57,6 +57,11 @@ async def on_initialized(
         await ls.initialized(params)
         await call_features(ls, "initialized", params)
 
+    @server.feature(types.SHUTDOWN)
+    async def on_shutdown(ls: EsbonioLanguageServer, params: None):
+        ls.lsp_shutdown(params)
+        await call_features(ls, "shutdown", params)
+
     @server.feature(types.TEXT_DOCUMENT_DID_CHANGE)
     async def on_document_change(
         ls: EsbonioLanguageServer, params: types.DidChangeTextDocumentParams