Using webDriverIO helper properly

What are you trying to achieve? To use webdriverio helper

What do you get instead? An error “Cannot read property ‘promise’ of undefined”.

webdriverIO test --
 try to locate element
 • I am on page "http://codecept.io/" (13.999 sec)
 • I try locate  (0.001 sec)
 ✖ FAILED in 16342ms


-- FAILURES:

  1) webdriverIO test: try to locate element:
     Cannot read property 'promise' of undefined
  
  Scenario Steps:
  
  - I.tryLocate() at Test.<anonymous> (livetv_test.js:5:7)
  - I.amOnPage("http://codecept.io/") at Test.<anonymous> (livetv_test.js:4:7)
  
  
  
  Run with --verbose flag to see NodeJS stacktrace


  FAIL  | 0 passed, 1 failed   // 16s

Provide test source code if related some_test.js:

Feature('webdriverIO test');

Scenario("try to locate element", function * (I) {
    I.amOnPage("http://codecept.io/");
    I.tryLocate();
});

WebDriverIOHelper.js:

'use strict';

class WebDriverIOHelper extends Helper {
    tryLocate() {
        const element = this.helpers['WebDriverIO'].browser.element;
        return element('h1');
    }
}

module.exports = WebDriverIOHelper;

Details

• CodeceptJS version: v1.0.0
• NodeJS Version: v8.4.0
• Operating System: macOs Sierra v 10.12.6
• SeleniumWebDriver version: ‘3.4.0’
• Configuration file:

{
  "output": "./output",
  "helpers": {
    "WebDriverIO": {
      "url": "http://localhost:3000",
      "windowSize": "maximize",
      "browser": "chrome",
      "restart": true,
      "smartWait": 15000
    },
    "WebDriverIOHelper": {
      "require": "./WebDriverIOHelper.js"
    }
  },
  "include": {
    "I": "./custom_steps.js"
  },
  "mocha": {
    "reporterOptions": {
      "mochaFile": "./output/result.xml"
    }
  },
  "bootstrap": "./bootstrap.js",
  "teardown": null,
  "hooks": [],
  "tests": "./*_test.js",
  "timeout": 5000,
  "multiple": {
    "default": {
      "grep": "signin",
      "browsers": [
        "chrome",
        "safari"
      ]
    }
  },
  "name": "tests"
}

[reubenmiller]

You’re welcome. I just noticed that you have a small typo in the test scenario aync.

Also the advantage of having the helper function return a promise instead of being an async function is that you can call it from the interactive shell and it behaves as expected.

Don’t forget to close the issue if everything works.

[alias8]

Awesome, thank you so much for your help! I adjusted the function to return the text in that element. I’ve updated the github repo with the changes.

    tryLocate(selector = 'h1') {
        const browser = this.helpers['WebDriverIO'].browser;

        return browser.element(selector).getText()
            .then((res) => {
                return res;
            })
            .catch((err) => {
                // Catch the error because webdriver.io throws if the element could not be found
                // Source: https://github.com/webdriverio/webdriverio/blob/master/lib/protocol/element.js
                return null;
            });
    }

and call it by using:

Feature('HomePage Tests');

Scenario('Check home page', async function (I) {
    I.amOnPage('http://codecept.io/');
    if(await I.tryLocate('h1') === "CodeceptJS") {
        console.log("text found!")
    } else {
        console.log("text not found!")
    }
    I.wait(10);
});