Merge pull request modelcontextprotocol#754 from cmgriffing/cmgriffing/fix-cli-truncated-output

Make cli output awaitable to prevent truncating the result

Author: olaservo

cli/src/index.ts

@@ -19,6 +19,7 @@ import {
 } from "./client/index.js";
 import { handleError } from "./error-handler.js";
 import { createTransport, TransportOptions } from "./transport.js";
+import { awaitableLog } from "./utils/awaitable-log.js";
 
 // JSON value type for CLI arguments
 type JsonValue =
@@ -167,7 +168,7 @@ async function callMethod(args: Args): Promise<void> {
       );
     }
 
-    console.log(JSON.stringify(result, null, 2));
+    await awaitableLog(JSON.stringify(result, null, 2));
   } finally {
     try {
       await disconnect(transport);

cli/src/utils/awaitable-log.ts

@@ -0,0 +1,7 @@
+export function awaitableLog(logValue: string): Promise<void> {
+  return new Promise<void>((resolve) => {
+    process.stdout.write(logValue, () => {
+      resolve();
+    });
+  });
+}