Function getFileAtRef

packages/cli/src/undo.ts:77–87

* Gets the content of a file at a given git ref. * Returns null if the file doesn't exist at that ref.

(projectCwd: string, gitRef: string, relPath: string)

 * Returns null if the file doesn't exist at that ref.
 */
function getFileAtRef(projectCwd: string, gitRef: string, relPath: string): string | null {
    try {
        return execSync(`git show ${gitRef}:${relPath}`, {
            cwd: projectCwd,
            stdio: ['pipe', 'pipe', 'pipe'],
            maxBuffer: 10 * 1024 * 1024, // 10MB
        }).toString();
    } catch {
        return null; // File didn't exist at that ref
    }
}

/**
 * Discovers files that changed since the session baseline by combining