refactor: replace get_language_id with get_language_config API

Replace the simple get_language_id method with a more comprehensive
get_language_config that provides language kind, file suffixes, and
project file patterns. This enables better language detection and
project root identification across all client implementations.

Author: observerw

src/lsp_client/capability/notification/text_document_synchronize.py

@@ -60,7 +60,7 @@ async def notify_text_document_opened(
             lsp_type.DidOpenTextDocumentParams(
                 text_document=lsp_type.TextDocumentItem(
                     uri=self.as_uri(file_path),
-                    language_id=self.get_language_id(),
+                    language_id=self.get_language_config().kind,
                     version=0,  # Version 0 for the initial open
                     text=file_content,
                 )

src/lsp_client/client/abc.py

@@ -19,6 +19,7 @@
 )
 from lsp_client.capability.notification import WithNotifyTextDocumentSynchronize
 from lsp_client.client.buffer import LSPFileBuffer
+from lsp_client.client.lang import LanguageConfig
 from lsp_client.jsonrpc.convert import (
     notification_serialize,
     request_deserialize,
@@ -109,8 +110,8 @@ def find_project_root(cls, path: Path) -> Path | None:
                 return parent
 
     @abstractmethod
-    def get_language_id(self) -> lsp_type.LanguageKind:
-        """The language ID of the client."""
+    def get_language_config(self) -> LanguageConfig:
+        """Get language-specific configuration for this client."""
 
     @abstractmethod
     def create_default_servers(self) -> DefaultServers:

src/lsp_client/client/lang.py

@@ -0,0 +1,47 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+from attrs import Factory, frozen
+
+from lsp_client.utils.workspace import lsp_type
+
+
+@frozen
+class LanguageConfig:
+    """Configuration for a programming language in the LSP client."""
+
+    kind: lsp_type.LanguageKind
+    """The kind of programming language."""
+
+    suffixes: list[str]
+    """File suffixes associated with the language."""
+
+    project_files: list[str]
+    """Files that indicate the root of a project for this language."""
+
+    exclude_files: list[str] = Factory(list)
+    """Files that indicate a directory should not be considered a project root for this language."""
+
+    def find_project_root(self, file_path: Path) -> Path | None:
+        """Find the project root directory for the given file path.
+
+        Args:
+            file_path (Path): The file path to check.
+        Returns:
+            Path | None: The project root directory if found, otherwise None.
+        """
+
+        if not file_path.is_file():
+            raise ValueError(f"Expected a file path, got: {file_path}")
+
+        if not any(file_path.name.endswith(suffix) for suffix in self.suffixes):
+            return
+
+        for parent in file_path.parents:
+            if any((parent / excl).exists() for excl in self.exclude_files):
+                return
+            if any((parent / proj).exists() for proj in self.project_files):
+                return parent
+
+        return file_path.parent

src/lsp_client/clients/base.py

@@ -5,6 +5,7 @@
 from typing import override
 
 from lsp_client.client.abc import Client
+from lsp_client.client.lang import LanguageConfig
 from lsp_client.utils.types import lsp_type
 
 
@@ -23,8 +24,18 @@ def check_project_root(cls, path: Path) -> bool:
         )
 
     @override
-    def get_language_id(self) -> lsp_type.LanguageKind:
-        return lsp_type.LanguageKind.Python
+    def get_language_config(self) -> LanguageConfig:
+        return LanguageConfig(
+            kind=lsp_type.LanguageKind.Python,
+            suffixes=[".py", ".pyi"],
+            project_files=[
+                "pyproject.toml",
+                "setup.py",
+                "setup.cfg",
+                "requirements.txt",
+                ".python-version",
+            ],
+        )
 
 
 class RustClientBase(Client, ABC):
@@ -33,8 +44,12 @@ def check_project_root(cls, path: Path) -> bool:
         return (path / "Cargo.toml").exists()
 
     @override
-    def get_language_id(self) -> lsp_type.LanguageKind:
-        return lsp_type.LanguageKind.Rust
+    def get_language_config(self) -> LanguageConfig:
+        return LanguageConfig(
+            kind=lsp_type.LanguageKind.Rust,
+            suffixes=[".rs"],
+            project_files=["Cargo.toml"],
+        )
 
 
 class GoClientBase(Client, ABC):
@@ -43,8 +58,12 @@ def check_project_root(cls, path: Path) -> bool:
         return (path / "go.mod").exists()
 
     @override
-    def get_language_id(self) -> lsp_type.LanguageKind:
-        return lsp_type.LanguageKind.Go
+    def get_language_config(self) -> LanguageConfig:
+        return LanguageConfig(
+            kind=lsp_type.LanguageKind.Go,
+            suffixes=[".go"],
+            project_files=["go.mod"],
+        )
 
 
 class TypeScriptClientBase(Client, ABC):
@@ -56,5 +75,9 @@ def check_project_root(cls, path: Path) -> bool:
         )
 
     @override
-    def get_language_id(self) -> lsp_type.LanguageKind:
-        return lsp_type.LanguageKind.TypeScript
+    def get_language_config(self) -> LanguageConfig:
+        return LanguageConfig(
+            kind=lsp_type.LanguageKind.TypeScript,
+            suffixes=[".ts", ".tsx", ".js", ".jsx", ".mjs", ".cjs"],
+            project_files=["package.json", "tsconfig.json", "jsconfig.json"],
+        )

src/lsp_client/clients/deno/client.py

@@ -41,6 +41,7 @@
     WithRespondWorkspaceFoldersRequest,
 )
 from lsp_client.client.abc import Client
+from lsp_client.client.lang import LanguageConfig
 from lsp_client.server import DefaultServers, ServerInstallationError
 from lsp_client.server.container import ContainerServer
 from lsp_client.server.local import LocalServer
@@ -142,8 +143,12 @@ def check_project_root(cls, path: Path) -> bool:
         return any((path / f).exists() for f in ("deno.json", "deno.jsonc"))
 
     @override
-    def get_language_id(self) -> lsp_type.LanguageKind:
-        return lsp_type.LanguageKind.TypeScript
+    def get_language_config(self) -> LanguageConfig:
+        return LanguageConfig(
+            kind=lsp_type.LanguageKind.TypeScript,
+            suffixes=[".ts", ".tsx", ".js", ".jsx", ".mjs"],
+            project_files=["deno.json", "deno.jsonc"],
+        )
 
     @override
     def create_default_servers(self) -> DefaultServers:

src/lsp_client/protocol/client.py

@@ -4,14 +4,17 @@
 from collections.abc import AsyncGenerator
 from contextlib import asynccontextmanager
 from pathlib import Path
-from typing import Protocol, runtime_checkable
+from typing import TYPE_CHECKING, Protocol, runtime_checkable
 
 import anyio
 
-from lsp_client.utils.types import AnyPath, Notification, Request, Response, lsp_type
+from lsp_client.utils.types import AnyPath, Notification, Request, Response
 from lsp_client.utils.uri import from_local_uri
 from lsp_client.utils.workspace import DEFAULT_WORKSPACE_DIR, Workspace
 
+if TYPE_CHECKING:
+    from lsp_client.client.lang import LanguageConfig
+
 
 @runtime_checkable
 class CapabilityClientProtocol(Protocol):
@@ -24,8 +27,8 @@ def get_workspace(self) -> Workspace:
         """The workspace folders of the client."""
 
     @abstractmethod
-    def get_language_id(self) -> lsp_type.LanguageKind:
-        """The language ID of the client."""
+    def get_language_config(self) -> LanguageConfig:
+        """Get language-specific configuration for this client."""
 
     @abstractmethod
     @asynccontextmanager