feat: Added /copy command for copying output to clipboard with new Command Service approach (#3706)

Co-authored-by: Abhi <43648792+abhipatel12@users.noreply.github.com>
Co-authored-by: N. Taylor Mullen <ntaylormullen@google.com>

packages/cli/src/ui/commands/copyCommand.ts

@@ -0,0 +1,62 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { copyToClipboard } from '../utils/commandUtils.js';
+import { SlashCommand, SlashCommandActionReturn } from './types.js';
+
+export const copyCommand: SlashCommand = {
+  name: 'copy',
+  description: 'Copy the last result or code snippet to clipboard',
+  action: async (context, _args): Promise<SlashCommandActionReturn | void> => {
+    const chat = await context.services.config?.getGeminiClient()?.getChat();
+    const history = chat?.getHistory();
+
+    // Get the last message from the AI (model role)
+    const lastAiMessage = history
+      ? history.filter((item) => item.role === 'model').pop()
+      : undefined;
+
+    if (!lastAiMessage) {
+      return {
+        type: 'message',
+        messageType: 'info',
+        content: 'No output in history',
+      };
+    }
+    // Extract text from the parts
+    const lastAiOutput = lastAiMessage.parts
+      ?.filter((part) => part.text)
+      .map((part) => part.text)
+      .join('');
+
+    if (lastAiOutput) {
+      try {
+        await copyToClipboard(lastAiOutput);
+
+        return {
+          type: 'message',
+          messageType: 'info',
+          content: 'Last output copied to the clipboard',
+        };
+      } catch (error) {
+        const message = error instanceof Error ? error.message : String(error);
+        console.debug(message);
+
+        return {
+          type: 'message',
+          messageType: 'error',
+          content: 'Failed to copy to the clipboard.',
+        };
+      }
+    } else {
+      return {
+        type: 'message',
+        messageType: 'info',
+        content: 'Last AI output contains no text to copy.',
+      };
+    }
+  },
+};