Add InitializeResult and ServerInfo

lsp_client/__init__.py

@@ -19,6 +19,7 @@
     HoverRequest,
     InitializeParams,
     InitializeRequest,
+    InitializeResult,
     InitializedNotification,
     LanguageKind,
     Location,
@@ -34,6 +35,7 @@
     ResponseError,
     ResponseMessage,
     ServerCapabilities,
+    ServerInfo,
     ShutdownRequest,
     TextDocumentDidChangeNotification,
     TextDocumentDidCloseNotification,
@@ -79,6 +81,7 @@
     "HoverRequest",
     "InitializeParams",
     "InitializeRequest",
+    "InitializeResult",
     "InitializedNotification",
     "LSPClient",
     "LSPErrorCodes",
@@ -93,6 +96,7 @@
     "ResponseError",
     "ResponseMessage",
     "ServerCapabilities",
+    "ServerInfo",
     "ShutdownRequest",
     "TextDocumentDidChangeNotification",
     "TextDocumentDidCloseNotification",

lsp_client/protocol.py

@@ -300,6 +300,24 @@ def __init__(self, **kwargs: Any) -> None:
         super(InitializeRequest, self).__init__(**kwargs)
 
 
+class ServerInfo(BaseModel):
+    """Information about the server. @since 3.15.0"""
+
+    #: The name of the server as defined by the server.
+    name: str
+    #: The server's version as defined by the server.
+    version: str | None = None
+
+
+class InitializeResult(BaseModel):
+    """The result returned from an ``initialize`` request."""
+
+    #: The capabilities the language server provides.
+    capabilities: ServerCapabilities
+    #: Information about the server. @since 3.15.0
+    serverInfo: ServerInfo | None = None
+
+
 class InitializedNotification(BaseNotification):
     def __init__(self, **kwargs: Any) -> None:
         kwargs["method"] = "initialized"

tests/test_protocol.py

@@ -21,6 +21,7 @@
     HoverRequest,
     InitializeParams,
     InitializeRequest,
+    InitializeResult,
     InitializedNotification,
     LanguageKind,
     Location,
@@ -35,6 +36,7 @@
     ResponseError,
     ResponseMessage,
     ServerCapabilities,
+    ServerInfo,
     ShutdownRequest,
     TextDocumentDidChangeNotification,
     TextDocumentDidCloseNotification,
@@ -462,6 +464,50 @@ def test_server_capabilities_position_encoding_optional():
     assert ServerCapabilities().model_dump(exclude_none=True) == {}
 
 
+def test_initialize_result_minimal():
+    result = InitializeResult(capabilities=ServerCapabilities())
+    data = result.model_dump(exclude_none=True)
+    # Only capabilities is required; serverInfo is omitted when absent.
+    assert data == {"capabilities": {}}
+    assert "serverInfo" not in data
+
+
+def test_initialize_result_with_server_info():
+    result = InitializeResult(
+        capabilities=ServerCapabilities(positionEncoding=PositionEncodingKind.UTF8),
+        serverInfo=ServerInfo(name="pyright", version="1.1.0"),
+    )
+    data = result.model_dump(exclude_none=True)
+    assert data == {
+        "capabilities": {"positionEncoding": "utf-8"},
+        "serverInfo": {"name": "pyright", "version": "1.1.0"},
+    }
+
+
+def test_server_info_version_optional():
+    data = ServerInfo(name="gopls").model_dump(exclude_none=True)
+    assert data == {"name": "gopls"}
+
+
+def test_server_info_requires_name():
+    with pytest.raises(ValidationError):
+        ServerInfo()
+
+
+def test_initialize_result_parses_from_response_payload():
+    # A server's initialize response coerces into nested models.
+    result = InitializeResult.model_validate(
+        {
+            "capabilities": {"positionEncoding": "utf-16"},
+            "serverInfo": {"name": "rust-analyzer"},
+        }
+    )
+    assert result.capabilities.positionEncoding == PositionEncodingKind.UTF16
+    assert result.serverInfo is not None
+    assert result.serverInfo.name == "rust-analyzer"
+    assert result.serverInfo.version is None
+
+
 def _range() -> Range:
     return Range(start=Position(line=1, character=0), end=Position(line=1, character=8))