helpers.js

/* globals communicate */

this.helpers = (function() {
  const exports = {};

  exports.Runner = class Runner {
    constructor() {
      this._logMessages = [];
    }

    log(...args) {
      this._logMessages.push(args);
    }

    querySelector(selector) {
      const element = document.querySelector(selector);
      if (!element) {
        const e = new Error(`Could not find element ${selector}`);
        e.name = "ElementNotFound";
        throw e;
      }
      return element;
    }

    querySelectorAll(selector) {
      return document.querySelectorAll(selector);
    }

    setReactInputValue(input, value) {
      // See https://hustle.bizongo.in/simulate-react-on-change-on-controlled-components-baa336920e04
      // for the why of this
      const nativeInputValueSetter = Object.getOwnPropertyDescriptor(
        window.HTMLInputElement.prototype,
        "value"
      ).set;
      nativeInputValueSetter.call(input, value);
      const inputEvent = new Event("input", { bubbles: true });
      input.dispatchEvent(inputEvent);
    }

    waitForSelector(selector, options) {
      const interval = (options && options.interval) || 50;
      const timeout = (options && options.timeout) || 1000;
      const minCount = (options && options.minCount) || 1;
      return new Promise((resolve, reject) => {
        const start = Date.now();
        const id = setInterval(() => {
          const result = document.querySelectorAll(selector);
          if (result.length && result.length >= minCount) {
            clearTimeout(id);
            if (options && options.all) {
              resolve(result);
            } else {
              resolve(result[0]);
            }
            return;
          }
          if (Date.now() > start + timeout) {
            const e = new Error(`Timeout waiting for ${selector}`);
            e.name = "TimeoutError";
            clearTimeout(id);
            reject(e);
          }
        }, interval);
      });
    }
  };

  exports.Runner.register = function() {
    const Class = this;
    for (const name of Object.getOwnPropertyNames(Class.prototype)) {
      if (name.startsWith("action_")) {
        const actionName = name.substr("action_".length);
        communicate.register(actionName, message => {
          const instance = new Class();
          try {
            return instance[name](message);
          } catch (e) {
            e.log = instance._logMessages;
            throw e;
          }
        });
      }
    }
  };

  return exports;
})();