AeroSpace CLI Commands Hang When Executed via Node.js child_process

[MichaelKilbane]

Summary:
While developing a companion app for AeroSpace to enhance workspace switching feedback, I've discovered that the list-workspaces, list-monitors, and list-windows commands hang indefinitely when executed through Node.js child_process.exec(). This occurs even though these commands work correctly when run directly in the terminal.

Environment:

• AeroSpace (v0.16.2-Beta)
• Node.js (v20.15.1)
• Electron-based application
• macOS (Sonoma v14.7)

Reproduction:

1. Use child_process.exec() to run any of these commands:
   aerospace list-workspaces --all
aerospace list-monitors
aerospace list-windows
2. Observe that the callback never executes

Expected behavior:

Commands should return JSON data promptly, as they do in the terminal.

Actual behavior:

Commands hang indefinitely without returning or throwing an error.

Technical Details:

Here's the relevant implementation that demonstrates the issue:

const execAsync = promisify(exec);

// This hangs indefinitely
const workspacesStdout = await execAsync('aerospace list-workspaces --all');

Additional Notes:

• which aerospace executes successfully, confirming the binary is accessible
• Direct terminal execution of these commands works as expected
• No error messages or timeouts occur; the process simply hangs

Would appreciate any insights into whether this might be related to how AeroSpace handles stdout/stderr when called programmatically vs. interactively.

[Gai-H]

I can confirm the same behavior on my side (different environment):

Environment

• AeroSpace v0.19.2-Beta
• Node.js v22.14.0
• Raycast extension (runs on Node.js inside Raycast)
• macOS Sequoia v15.6

Findings

• Using child_process.spawn also hangs
• Even aerospace --version hangs when executed via spawn
• However, child_process.execFileSync works without any issues

Sharing this info in case it helps narrow down the cause.

[Gai-H]

I had some time, so I investigated the cause of this behavior.
It turns out the CLI hangs because it is waiting for at least one line of input from stdin. (Related: #1682)

Therefore, closing stdin on the Node.js side resolves the problem:

const { exec } = require("node:child_process");

const child = exec("aerospace --version", (error, stdout, stderr) => {
  console.log(`stdout: ${stdout}`);
});

// close stdin
child.stdin.end();

[nikitabobko]

Tracking issue: #1683