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Can't use WebDriver grab methods - unexpected identifier

See original GitHub issue

I’m using Selenium and Firefox. I’m trying to use I.grabTextFrom or I.grabAttributeFrom, and I get the error:

CodeceptJS v0.3.3
Test root is assumed to be /Users/andrew/code/myapp

Unexpected identifier

SyntaxError:
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:404:25)
    at Object.Module._extensions..js (module.js:432:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:313:12)
    at Module.require (module.js:366:17)
    at require (module.js:385:17)
    at /Users/andrew/.nvm/versions/node/v5.1.1/lib/node_modules/codeceptjs/node_modules/mocha/lib/mocha.js:219:27
    at Array.forEach (native)
    at Mocha.loadFiles (/Users/andrew/.nvm/versions/node/v5.1.1/lib/node_modules/codeceptjs/node_modules/mocha/lib/mocha.js:216:14)

I’ve defined an element in my dom, with an id ‘test’, and a value ‘foo’:

<div id="test">Foo</div>

And I try to grab the value:

    var test = yield I.grabTextFrom('#test');

This causes the above error. Not sure why.

Issue Analytics

State:
Created 7 years ago
Comments:5 (1 by maintainers)

Top GitHub Comments

9reactions

neil-scommented, Jun 25, 2016

@andrewhl , I’ve figured out the reason, at least for my instance of the bug, and it’s entirely user error. When I RTFM, I realized that I wasn’t using a generator function for the scenario. From the documentation:

All actions starting with grab prefix are expected to return data. In order to synchronize this step with a scenario you should pause test execution with yield keyword of ES6. To make it work your test should be written inside a generator function (notice * in its definition):

Scenario('use page title', function*(I) {
  // ...
  var password = yield I.grabTextFrom('#password');
  I.fillField('password', password);
});

Without it being a generator function, that yield keyword is nonsense to the JS engine, hence the unknown identifier error.

2reactions

neil-scommented, Jun 24, 2016

I am reproducing this same error.

Feature('Hello');

Scenario('test something', (I) => {
    I.amOnPage('/');
    var title = yield I.grabTitle();
});

{
  "tests": "./*_test.js",
  "timeout": 10000,
  "output": "./output",
  "helpers": {
    "WebDriverIO": {
      "url": "http://www.google.com",
      "browser": "chrome"
    }
  },
  "include": {
    "I": "./steps_file.js"
  },
  "bootstrap": false,
  "mocha": {},
  "name": "somename"
}

So simply going to Google and getting the title causes this issue. Removing the grabTitle line makes the error go away. Stacktrace is the same as OP.

Unexpected identifier

SyntaxError:
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:373:25)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at Module.require (module.js:353:17)
    at require (internal/module.js:12:17)
    at C:\Users\Neil\AppData\Roaming\nvm\v4.4.5\node_modules\codeceptjs\node_modules\mocha\lib\mocha.js:220:27
    at Array.forEach (native)
    at Mocha.loadFiles (C:\Users\Neil\AppData\Roaming\nvm\v4.4.5\node_modules\codeceptjs\node_modules\mocha\lib\mocha.js:217:14)

Versions: Codecept: 0.3.5 Node: 4.4.5 Windows: 10