# bun/no-console-window-flash

> Require `windowsHide` for a child process that does not share a stream with its parent

On Windows, a child process started from an app without a console gets its own console window. The window opens and closes again as the process runs, which users see as a black flash. `windowsHide: true` prevents it and has no effect on other systems.

The rule looks at `exec`, `execSync`, `execFile`, `execFileSync`, `spawn`, and `spawnSync` from `node:child_process`, and at `Bun.spawn` and `Bun.spawnSync`.

{/* Generated by src/codegen/lint-rule-docs.ts. Do not edit this section. */}

## Configure

Off by default. To turn it on:

```toml bunfig.toml
[lint.rules]
"bun/no-console-window-flash" = "error" # or "warn"
```

{/* End of the generated section. */}

## Examples

Reported:

{/* bad */}
```js
import { execFile } from "node:child_process";

execFile("git", ["status", "--short"], (error, stdout) => {
  show(stdout);
});
```

{/* bad */}
```js
const git = Bun.spawn(["git", "status", "--short"], { stdout: "pipe" });
```

Not reported:

{/* good */}
```js
import { execFile } from "node:child_process";

execFile("git", ["status", "--short"], { windowsHide: true }, (error, stdout) => {
  show(stdout);
});

const git = Bun.spawn(["git", "status", "--short"], { stdout: "pipe", windowsHide: true });
```

A process that inherits a stream writes to its parent's terminal, so it isn't reported. Any value for `windowsHide` counts, because writing `false` is a deliberate choice. Options that aren't an object literal in the call, or that spread another object, aren't checked:

{/* good */}
```js
import { spawn } from "node:child_process";

spawn("bun", ["test"], { stdio: "inherit" });
spawn("bun", ["test"], { stdio: ["ignore", "inherit", "pipe"] });
spawn("notepad", [file], { windowsHide: false });
spawn("bun", ["test"], options);
spawn("bun", ["test"], { ...options, cwd });
```

## When not to use it

Code that never runs on Windows doesn't need the option.