Function writeFileAtomic

packages/cli/src/lib/atomic-write.ts:15–28

(targetPath: string, data: string)

 * relying on each call site to remember an ensureDir.
 */
export function writeFileAtomic(targetPath: string, data: string): void {
    mkdirSync(dirname(targetPath), { recursive: true });
    const tmpPath = `${targetPath}.tmp`;
    writeFileSync(tmpPath, data, { encoding: "utf-8" });
    try {
        if (statSync(targetPath, { throwIfNoEntry: false })?.isFile()) {
            const mode = statSync(targetPath).mode & 0o777;
            chmodSync(tmpPath, mode);
        }
    } catch {
        // New file — default umask applies.
    }
    renameSync(tmpPath, targetPath);
}