some description

snapshot.ts

import fs from 'node:fs';
import path from 'node:path';

// a comment

export class SnapshotState {
  private snapshotPath: string;
  private id: number;

  constructor(snapshotDir: string, id: number) {
    this.id = id;
    this.snapshotPath = path.join(process.cwd(), snapshotDir, 'test.snap');
  }

  loadSnapshot<T>(actual: T): T | undefined {
    try {
      const data = fs.readFileSync(this.snapshotPath, 'utf-8');
      const snapshots = JSON.parse(data) as Record<number, T>;
      return snapshots[this.id];
    } catch (e: any) {
      return undefined;
    }
  }

  saveSnapshot<T>(actual: T) {
    let snapshots: Record<number, T> = {};
    try {
      const data = fs.readFileSync(this.snapshotPath, 'utf-8');
      snapshots = JSON.parse(data) as Record<number, T>;
    } catch (e) {
      // File doesn't exist or is invalid, start with empty snapshots
    }
    snapshots[this.id] = actual;
    fs.writeFileSync(this.snapshotPath, JSON.stringify(snapshots, null, 2));
  }
}