import wrap = require('spawn-wrap');

const wrapFile = require.resolve('./spawnWrapper');

export class SpawnWrapperUtils {
  private static unwrapFn: () => void;

  static wrap() {
    if (!SpawnWrapperUtils.unwrapFn) {
      SpawnWrapperUtils.unwrapFn = wrap([wrapFile]);
    }
  }

  static unwrap() {
    if (SpawnWrapperUtils.unwrapFn) {
      this.unwrapFn();
      this.unwrapFn = null;
    }
  }

  static async transaction(fn) {
    SpawnWrapperUtils.wrap();
    let ret;
    let caughtError;
    try {
      ret = await fn();
    } catch (error) {
      caughtError = error;
    } finally {
      SpawnWrapperUtils.unwrap();
    }
    if (caughtError) {
      throw caughtError;
    }
    return ret;
  }

}