cli-engine/lib/cache.js

Generic CLI Framework

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _fsExtra = require('fs-extra');

var _fsExtra2 = _interopRequireDefault(_fsExtra);

var _moment = require('moment');

var _moment2 = _interopRequireDefault(_moment);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

// TODO: move to its own package

exports.default = class {
  static async fetch(cachePath, cacheDuration, options) {
    let cachePresent = await _fsExtra2.default.exists(cachePath);
    if (cachePresent && !this._isStale(cachePath, cacheDuration)) {
      return _fsExtra2.default.readJSON(cachePath);
    }
    const cache = await options.cacheFn();
    // TODO: move this to a fork
    await this._updateCache(cachePath, cache);
    return cache;
  }

  static async _updateCache(cachePath, cache) {
    await _fsExtra2.default.ensureFile(cachePath);
    await _fsExtra2.default.writeJSON(cachePath, cache);
  }

  static _isStale(cachePath, cacheDuration) {
    return this._mtime(cachePath).isBefore((0, _moment2.default)().subtract(cacheDuration, 'seconds'));
  }

  static _mtime(f) {
    return (0, _moment2.default)(_fsExtra2.default.statSync(f).mtime);
  }
};