Fix: Allow --agent flag without prompt in headless mode (#8227)

* Fix: Allow --agent flag without prompt in headless mode

- Modified prompt validation to check for --agent flag presence
- Agent files can provide their own prompts, so no user prompt is required
- Added example usage with --agent flag to error message
- Added test case to verify --agent flag bypasses prompt requirement

Fixes issue where 'cn -p --agent owner/package' incorrectly required a prompt

Generated with [Continue](https://continue.dev)

Co-Authored-By: Continue <[email protected]>
Co-authored-by: Username <[email protected]>

* fix: better examples when prompt is not provided

---------

Co-authored-by: Continue Agent <[email protected]>
Co-authored-by: Continue <[email protected]>
Co-authored-by: Username <[email protected]>
Co-authored-by: Dallin Romney <[email protected]>

Author: 4 people

extensions/cli/src/e2e/headless-missing-prompt.test.ts

@@ -147,4 +147,32 @@ models:
       "A prompt is required when using the -p/--print flag",
     );
   });
+
+  it("should not require prompt when using --agent flag with -p", async () => {
+    await createTestConfig(
+      context,
+      `name: Test Assistant
+version: 1.0.0
+schema: v1
+models:
+  - model: gpt-4
+    provider: openai
+    apiKey: test-key
+    roles:
+      - chat`,
+    );
+
+    const result = await runCLI(context, {
+      args: ["-p", "--config", context.configPath, "--agent", "test/agent"],
+      env: { OPENAI_API_KEY: "test-key" },
+      expectError: true, // Will fail trying to load agent from hub, but should pass prompt validation
+      timeout: 5000,
+    });
+
+    // Should NOT show the "prompt required" error message
+    const output = result.stderr + result.stdout;
+    expect(output).not.toContain(
+      "A prompt is required when using the -p/--print flag",
+    );
+  });
 });

extensions/cli/src/index.ts

@@ -216,15 +216,18 @@ addCommonOptions(program)
       }
     }
 
-    // In headless mode, ensure we have a prompt
-    if (options.print && !prompt) {
+    // In headless mode, ensure we have a prompt unless using --agent flag
+    // Agent files can provide their own prompts
+    if (options.print && !prompt && !options.agent) {
       safeStderr(
-        "Error: A prompt is required when using the -p/--print flag.\n\n",
+        "Error: A prompt is required when using the -p/--print flag, unless --prompt or --agent is provided.\n\n",
       );
       safeStderr("Usage examples:\n");
       safeStderr('  cn -p "please review my current git diff"\n');
       safeStderr('  echo "hello" | cn -p\n');
       safeStderr('  cn -p "analyze the code in src/"\n');
+      safeStderr("  cn -p --agent my-org/my-agent\n");
+      safeStderr("  cn -p --prompt my-org/my-prompt\n");
       await gracefulExit(1);
     }