editor/code: add option to suppress internal error notifications

editors/code/package.json

@@ -502,6 +502,11 @@
                     "default": true,
                     "type": "boolean"
                 },
+                "rust-analyzer.showRequestFailedErrorNotification": {
+                    "markdownDescription": "Whether to show error notifications for failing requests.",
+                    "default": true,
+                    "type": "boolean"
+                },
                 "rust-analyzer.showDependenciesExplorer": {
                     "markdownDescription": "Whether to show the dependencies view.",
                     "default": true,

editors/code/src/client.ts

@@ -10,6 +10,7 @@ import { type Config, prepareVSCodeConfig } from "./config";
 import { randomUUID } from "crypto";
 import { sep as pathSeparator } from "path";
 import { unwrapUndefinable } from "./undefinable";
+import { RaLanguageClient } from "./lang_client";
 
 export interface Env {
     [name: string]: string;
@@ -363,7 +364,7 @@ export async function createClient(
         },
     };
 
-    const client = new lc.LanguageClient(
+    const client = new RaLanguageClient(
         "rust-analyzer",
         "Rust Analyzer Language Server",
         serverOptions,

editors/code/src/lang_client.ts

@@ -0,0 +1,26 @@
+import * as lc from "vscode-languageclient/node";
+import * as vscode from "vscode";
+
+export class RaLanguageClient extends lc.LanguageClient {
+    override handleFailedRequest<T>(
+        type: lc.MessageSignature,
+        token: vscode.CancellationToken | undefined,
+        error: any,
+        defaultValue: T,
+        showNotification?: boolean | undefined,
+    ): T {
+        const showError = vscode.workspace
+            .getConfiguration("rust-analyzer")
+            .get("showRequestFailedErrorNotification");
+        if (
+            !showError &&
+            error instanceof lc.ResponseError &&
+            error.code === lc.ErrorCodes.InternalError
+        ) {
+            // Don't show notification for internal errors, these are emitted by r-a when a request fails.
+            showNotification = false;
+        }
+
+        return super.handleFailedRequest(type, token, error, defaultValue, showNotification);
+    }
+}