From dac33c8ecb2833287f69567b65c9c3dff486f6eb Mon Sep 17 00:00:00 2001
From: Vincent Koc <vincentkoc@ieee.org>
Date: Mon, 1 Jun 2026 11:49:54 +0200
Subject: [PATCH] fix(e2e): cap pty transcript output

---
 scripts/e2e/lib/run-with-pty.mjs      | 32 +++++++++++++++++--
 test/scripts/e2e-run-with-pty.test.ts | 46 ++++++++++++++++++++-------
 2 files changed, 64 insertions(+), 14 deletions(-)

diff --git a/scripts/e2e/lib/run-with-pty.mjs b/scripts/e2e/lib/run-with-pty.mjs
index c3e90c1d2ca..dd63de45a39 100644
--- a/scripts/e2e/lib/run-with-pty.mjs
+++ b/scripts/e2e/lib/run-with-pty.mjs
@@ -5,6 +5,7 @@ import { spawn } from "@lydell/node-pty";
 import { readPositiveIntEnv } from "./env-limits.mjs";
 
 const [logPath, command, ...args] = process.argv.slice(2);
+const OUTPUT_MAX_BYTES = readPositiveIntEnv("OPENCLAW_E2E_PTY_OUTPUT_MAX_BYTES", 16 * 1024 * 1024);
 
 if (!logPath || !command) {
   console.error("usage: run-with-pty.mjs <log-path> <command> [args...]");
@@ -21,10 +22,37 @@ const pty = spawn(command, args, {
 });
 
 let exiting = false;
+const outputLimitMarker = `\n[run-with-pty output truncated after ${OUTPUT_MAX_BYTES} bytes]\n`;
+const outputState = {
+  bytes: 0,
+  truncated: false,
+};
+
+function writeCappedOutput(data) {
+  if (outputState.truncated) {
+    return;
+  }
+  const buffer = Buffer.from(data);
+  const remainingBytes = OUTPUT_MAX_BYTES - outputState.bytes;
+  if (buffer.byteLength <= remainingBytes) {
+    outputState.bytes += buffer.byteLength;
+    log.write(buffer);
+    process.stdout.write(buffer);
+    return;
+  }
+  if (remainingBytes > 0) {
+    const head = buffer.subarray(0, remainingBytes);
+    log.write(head);
+    process.stdout.write(head);
+  }
+  outputState.bytes = OUTPUT_MAX_BYTES;
+  outputState.truncated = true;
+  log.write(outputLimitMarker);
+  process.stdout.write(outputLimitMarker);
+}
 
 pty.onData((data) => {
-  log.write(data);
-  process.stdout.write(data);
+  writeCappedOutput(data);
 });
 
 pty.onExit(({ exitCode, signal }) => {
diff --git a/test/scripts/e2e-run-with-pty.test.ts b/test/scripts/e2e-run-with-pty.test.ts
index f54b610f791..822a35856db 100644
--- a/test/scripts/e2e-run-with-pty.test.ts
+++ b/test/scripts/e2e-run-with-pty.test.ts
@@ -11,19 +11,18 @@ const scriptPath = path.join(repoRoot, "scripts/e2e/lib/run-with-pty.mjs");
 function runPtyProbe(
   logPath: string,
   env: Record<string, string> = {},
+  command: string[] = [
+    "/bin/bash",
+    "-lc",
+    'printf "prompt\\n"; IFS= read -r value; printf "got:%s\\n" "$value"',
+  ],
+  input = "abc\n",
 ): Promise<{ code: number | null; stdout: string; stderr: string }> {
   return new Promise((resolve, reject) => {
-    const child = spawn(
-      process.execPath,
-      [
-        scriptPath,
-        logPath,
-        "/bin/bash",
-        "-lc",
-        'printf "prompt\\n"; IFS= read -r value; printf "got:%s\\n" "$value"',
-      ],
-      { env: { ...process.env, ...env }, stdio: ["pipe", "pipe", "pipe"] },
-    );
+    const child = spawn(process.execPath, [scriptPath, logPath, ...command], {
+      env: { ...process.env, ...env },
+      stdio: ["pipe", "pipe", "pipe"],
+    });
     let stdout = "";
     let stderr = "";
     const timeout = setTimeout(() => {
@@ -47,7 +46,7 @@ function runPtyProbe(
       clearTimeout(timeout);
       resolve({ code, stdout, stderr });
     });
-    child.stdin.end("abc\n");
+    child.stdin.end(input);
   });
 }
 
@@ -81,4 +80,27 @@ describe("run-with-pty", () => {
       await rm(tempRoot, { recursive: true, force: true });
     }
   });
+
+  it("caps noisy PTY output in stdout and transcript logs", async () => {
+    const tempRoot = await mkdtemp(path.join(os.tmpdir(), "openclaw-run-with-pty-"));
+    const logPath = path.join(tempRoot, "pty.log");
+    try {
+      const result = await runPtyProbe(
+        logPath,
+        { OPENCLAW_E2E_PTY_OUTPUT_MAX_BYTES: "64" },
+        [process.execPath, "-e", "process.stdout.write('x'.repeat(2048))"],
+        "",
+      );
+      const log = await readFile(logPath, "utf8");
+      const marker = "[run-with-pty output truncated after 64 bytes]";
+
+      expect(result).toMatchObject({ code: 0, stderr: "" });
+      expect(result.stdout).toContain(marker);
+      expect(log).toContain(marker);
+      expect(result.stdout.length).toBeLessThan(512);
+      expect(log.length).toBeLessThan(512);
+    } finally {
+      await rm(tempRoot, { recursive: true, force: true });
+    }
+  });
 });