feat: add basedpyright (#5712)

## 📝 Summary

Closes #1163

// cc: @nojaf 

## 📋 Checklist

- [x] I have read the [contributor
guidelines](https://github.com/marimo-team/marimo/blob/main/CONTRIBUTING.md).
- [x] For large changes, or changes that affect the public API: this
change was discussed or approved through an issue, on
[Discord](https://marimo.io/discord?ref=pr), or the community
[discussions](https://github.com/marimo-team/marimo/discussions) (Please
provide a link if applicable).
- [ ] I have added tests for the changes made.
- [ ] I have run the code and verified that it works as expected.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: winstxnhdw

frontend/src/components/app-config/user-config-form.tsx

@@ -484,6 +484,49 @@ export const UserConfigForm: React.FC = () => {
                   </div>
                 )}
               />
+              <FormField
+                control={form.control}
+                name="language_servers.basedpyright.enabled"
+                render={({ field }) => (
+                  <div className="flex flex-col gap-1">
+                    <FormItem className={formItemClasses}>
+                      <FormLabel>
+                        <Badge variant="defaultOutline" className="mr-2">
+                          Beta
+                        </Badge>
+                        basedpyright (
+                        <ExternalLink href="https://github.com/DetachHead/basedpyright">
+                          docs
+                        </ExternalLink>
+                        )
+                      </FormLabel>
+                      <FormControl>
+                        <Checkbox
+                          data-testid="basedpyright-checkbox"
+                          checked={field.value}
+                          disabled={field.disabled}
+                          onCheckedChange={(checked) => {
+                            field.onChange(Boolean(checked));
+                          }}
+                        />
+                      </FormControl>
+                      <FormMessage />
+                      <IsOverridden
+                        userConfig={config}
+                        name="language_servers.basedpyright.enabled"
+                      />
+                    </FormItem>
+                    {field.value && !capabilities.basedpyright && (
+                      <Banner kind="danger">
+                        basedpyright is not available in your current
+                        environment. Please install{" "}
+                        <Kbd className="inline">basedpyright</Kbd> in your
+                        environment.
+                      </Banner>
+                    )}
+                  </div>
+                )}
+              />
               <FormField
                 control={form.control}
                 name="language_servers.ty.enabled"

frontend/src/core/codemirror/language/languages/python.ts

@@ -153,6 +153,24 @@ const tyLspClient = once((_: LSPConfig) => {
   );
 });
 
+const pyrightClient = once((_: LSPConfig) => {
+  const lspClientOpts = {
+    transport: createTransport("basedpyright"),
+    rootUri: getLSPDocumentRootUri(),
+    workspaceFolders: [],
+  };
+
+  // We wrap the client in a NotebookLanguageServerClient to add some
+  // additional functionality to handle multiple cells
+  return new NotebookLanguageServerClient(
+    new LanguageServerClient({
+      ...lspClientOpts,
+      autoClose: false,
+    }),
+    {},
+  );
+});
+
 /**
  * Language adapter for Python.
  */
@@ -209,6 +227,9 @@ export class PythonLanguageAdapter implements LanguageAdapter<{}> {
       if (lspConfig?.ty?.enabled && hasCapability("ty")) {
         clients.push(tyLspClient(lspConfig));
       }
+      if (lspConfig?.basedpyright?.enabled && hasCapability("basedpyright")) {
+        clients.push(pyrightClient(lspConfig));
+      }
 
       if (clients.length > 0) {
         const client =

frontend/src/core/codemirror/lsp/transports.ts

@@ -12,7 +12,9 @@ import { getRuntimeManager } from "../../runtime/config";
  * @param serverName - The name of the LSP server.
  * @returns The transport.
  */
-export function createTransport(serverName: "pylsp" | "copilot" | "ty") {
+export function createTransport(
+  serverName: "pylsp" | "basedpyright" | "copilot" | "ty",
+) {
   const runtimeManager = getRuntimeManager();
   const transport = new WebSocketTransport(
     runtimeManager.getLSPURL(serverName).toString(),

frontend/src/core/config/capabilities.ts

@@ -6,6 +6,7 @@ import { store } from "../state/jotai";
 export const capabilitiesAtom = atom<Capabilities>({
   terminal: false,
   pylsp: false,
+  basedpyright: false,
   ty: false,
 });
 

frontend/src/core/runtime/runtime.ts

@@ -135,7 +135,7 @@ export class RuntimeManager {
   /**
    * The URL of the copilot server.
    */
-  getLSPURL(lsp: "pylsp" | "copilot" | "ty"): URL {
+  getLSPURL(lsp: "pylsp" | "basedpyright" | "copilot" | "ty"): URL {
     if (lsp === "copilot") {
       // For copilot, don't include any query parameters
       const url = this.formatWsURL(`/lsp/${lsp}`);

marimo/_config/config.py

@@ -339,6 +339,18 @@ class PythonLanguageServerConfig(TypedDict, total=False):
     enable_pyflakes: bool
 
 
+@dataclass
+class BasedpyrightServerConfig(TypedDict, total=False):
+    """
+    Configuration options for basedpyright Language Server.
+
+    basedpyright handles completion, hover, go-to-definition, and diagnostics,
+    but we only use it for diagnostics.
+    """
+
+    enabled: bool
+
+
 @dataclass
 class TyLanguageServerConfig(TypedDict, total=False):
     """
@@ -361,6 +373,7 @@ class LanguageServersConfig(TypedDict, total=False):
     """
 
     pylsp: PythonLanguageServerConfig
+    basedpyright: BasedpyrightServerConfig
     ty: TyLanguageServerConfig
 
 

marimo/_dependencies/dependencies.py

@@ -222,6 +222,7 @@ class DependencyManager:
     panel = Dependency("panel")
     sqlalchemy = Dependency("sqlalchemy")
     pylsp = Dependency("pylsp")
+    basedpyright = Dependency("basedpyright")
     ty = Dependency("ty")
     pytest = Dependency("pytest")
     vegafusion = Dependency("vegafusion")

marimo/_messaging/ops.py

@@ -419,11 +419,13 @@ class KernelCapabilities:
     terminal: bool = False
     pylsp: bool = False
     ty: bool = False
+    basedpyright: bool = False
 
     def __post_init__(self) -> None:
         # Only available in mac/linux
         self.terminal = not is_windows() and not is_pyodide()
         self.pylsp = DependencyManager.pylsp.has()
+        self.basedpyright = DependencyManager.basedpyright.has()
         self.ty = DependencyManager.ty.has()
 
 

marimo/_server/lsp.py

@@ -226,6 +226,48 @@ def missing_binary_alert(self) -> Alert:
         )
 
 
+class BasedpyrightServer(BaseLspServer):
+    id = "basedpyright"
+
+    def start(self) -> Optional[Alert]:
+        # basedpyright is not required, so we don't want to alert or fail if it is not installed
+        if not DependencyManager.basedpyright.has():
+            LOGGER.debug("basedpyright is not installed. Skipping LSP server.")
+            return None
+        return super().start()
+
+    def validate_requirements(self) -> Union[str, Literal[True]]:
+        if not DependencyManager.basedpyright.has():
+            return "basedpyright is missing. Install it with `pip install basedpyright`."
+
+        if not DependencyManager.which("node"):
+            return "node.js binary is missing. Install node at https://nodejs.org/."
+
+        return True
+
+    def get_command(self) -> list[str]:
+        lsp_bin = marimo_package_path() / "_lsp" / "index.cjs"
+        log_file = _loggers.get_log_directory() / "basedpyright-lsp.log"
+
+        return [
+            "node",
+            str(lsp_bin),
+            "--port",
+            str(self.port),
+            "--lsp",
+            "basedpyright-langserver --stdio",
+            "--log-file",
+            str(log_file),
+        ]
+
+    def missing_binary_alert(self) -> Alert:
+        return Alert(
+            title="basedpyright: Connection Error",
+            description="<span><a class='hyperlink' href='https://docs.basedpyright.com'>Install basedpyright</a> for type checking support.</span>",
+            variant="danger",
+        )
+
+
 class TyServer(BaseLspServer):
     id = "ty"
 
@@ -284,6 +326,7 @@ def is_running(self) -> bool:
 class CompositeLspServer(LspServer):
     LANGUAGE_SERVERS = {
         "pylsp": PyLspServer,
+        "basedpyright": BasedpyrightServer,
         "ty": TyServer,
         "copilot": CopilotLspServer,
     }

packages/openapi/api.yaml

@@ -1280,6 +1280,8 @@ components:
           type: object
         capabilities:
           properties:
+            basedpyright:
+              type: boolean
             pylsp:
               type: boolean
             terminal:
@@ -1290,6 +1292,7 @@ components:
           - terminal
           - pylsp
           - ty
+          - basedpyright
           type: object
         cell_ids:
           items:
@@ -1638,6 +1641,11 @@ components:
           type: object
         language_servers:
           properties:
+            basedpyright:
+              properties:
+                enabled:
+                  type: boolean
+              type: object
             pylsp:
               properties:
                 enable_flake8:
@@ -2741,7 +2749,7 @@ components:
       type: object
 info:
   title: marimo API
-  version: 0.14.13
+  version: 0.14.15
 openapi: 3.1.0
 paths:
   /@file/{filename_and_length}: