Auto merge of #14067 - jonas-schievink:lazy-trace-output, r=jonas-schievink

fix: Lazily create the trace output channel

Fixes rust-lang/rust-analyzer#13055

Author: bors

editors/code/src/ctx.ts

@@ -4,7 +4,7 @@ import * as ra from "./lsp_ext";
 
 import { Config, substituteVSCodeVariables } from "./config";
 import { createClient } from "./client";
-import { isRustDocument, isRustEditor, log, RustEditor } from "./util";
+import { isRustDocument, isRustEditor, LazyOutputChannel, log, RustEditor } from "./util";
 import { ServerStatusParams } from "./lsp_ext";
 import { PersistentState } from "./persistent_state";
 import { bootstrap } from "./bootstrap";
@@ -128,9 +128,7 @@ export class Ctx {
         }
 
         if (!this.traceOutputChannel) {
-            this.traceOutputChannel = vscode.window.createOutputChannel(
-                "Rust Analyzer Language Server Trace"
-            );
+            this.traceOutputChannel = new LazyOutputChannel("Rust Analyzer Language Server Trace");
             this.pushExtCleanup(this.traceOutputChannel);
         }
         if (!this.outputChannel) {

editors/code/src/util.ts

@@ -166,3 +166,49 @@ export function execute(command: string, options: ExecOptions): Promise<string>
         });
     });
 }
+
+export class LazyOutputChannel implements vscode.OutputChannel {
+    constructor(name: string) {
+        this.name = name;
+    }
+
+    name: string;
+    _channel: vscode.OutputChannel | undefined;
+
+    get channel(): vscode.OutputChannel {
+        if (!this._channel) {
+            this._channel = vscode.window.createOutputChannel(this.name);
+        }
+        return this._channel;
+    }
+
+    append(value: string): void {
+        this.channel.append(value);
+    }
+    appendLine(value: string): void {
+        this.channel.appendLine(value);
+    }
+    replace(value: string): void {
+        this.channel.replace(value);
+    }
+    clear(): void {
+        if (this._channel) {
+            this._channel.clear();
+        }
+    }
+    show(preserveFocus?: boolean): void;
+    show(column?: vscode.ViewColumn, preserveFocus?: boolean): void;
+    show(column?: any, preserveFocus?: any): void {
+        this.channel.show(column, preserveFocus);
+    }
+    hide(): void {
+        if (this._channel) {
+            this._channel.hide();
+        }
+    }
+    dispose(): void {
+        if (this._channel) {
+            this._channel.dispose();
+        }
+    }
+}