Add ruff.format.backend setting

package.json

@@ -231,6 +231,20 @@
           "scope": "resource",
           "type": "array"
         },
+        "ruff.format.backend": {
+          "default": "internal",
+          "markdownDescription": "The backend to use for formatting.",
+          "enum": [
+            "internal",
+            "uv"
+          ],
+          "enumDescriptions": [
+            "Use Ruff's built-in formatter.",
+            "Use uv for formatting (requires uv >= 0.8.13)"
+          ],
+          "scope": "resource",
+          "type": "string"
+        },
         "ruff.format.preview": {
           "default": null,
           "markdownDescription": "Enable [preview mode](https://docs.astral.sh/ruff/settings/#format_preview) for the formatter; enables unstable formatting.\n\n**This setting is used only by the native server.**",

src/common/settings.ts

@@ -25,6 +25,8 @@ type NativeServer = boolean | "on" | "off" | "auto";
 
 type LogLevel = "error" | "warn" | "info" | "debug" | "trace";
 
+type FormatterBackend = "internal" | "uv";
+
 type CodeAction = {
   disableRuleComment?: {
     enable?: boolean;
@@ -47,6 +49,7 @@ type Lint = {
 type Format = {
   args?: string[];
   preview?: boolean;
+  backend?: FormatterBackend;
 };
 
 export interface ISettings {
@@ -171,6 +174,7 @@ export async function getWorkspaceSettings(
     format: {
       args: resolveVariables(config.get<string[]>("format.args") ?? [], workspace),
       preview: config.get<boolean>("format.preview"),
+      backend: config.get<FormatterBackend>("format.backend") ?? "internal",
     },
     enable: config.get<boolean>("enable") ?? true,
     organizeImports: config.get<boolean>("organizeImports") ?? true,
@@ -240,6 +244,7 @@ export async function getGlobalSettings(namespace: string): Promise<ISettings> {
     format: {
       args: getGlobalValue<string[]>(config, "format.args", []),
       preview: getOptionalGlobalValue<boolean>(config, "format.preview"),
+      backend: getGlobalValue<FormatterBackend>(config, "format.backend", "internal"),
     },
     enable: getGlobalValue<boolean>(config, "enable", true),
     organizeImports: getGlobalValue<boolean>(config, "organizeImports", true),
@@ -281,6 +286,7 @@ export function checkIfConfigurationChanged(
     `${namespace}.path`,
     `${namespace}.showNotifications`,
     `${namespace}.format.preview`,
+    `${namespace}.format.backend`,
     `${namespace}.exclude`,
     `${namespace}.lineLength`,
     `${namespace}.configurationPreference`,