Executing Javascript on the Browser

These commands allow you execute Javascript on the browser during the test.

UI.execute

Executes Javascript on the browser.

Note that the script will run in the browser's context, and will have no access to any variables declared in the scope of the test scripts. It will have access to variables available in the browser, such as window, document, and libraries exposed by the webpage such as jQuery.

Usage

UI.execute(script, args)
Parameter Type Remarks
script function \ string Javascript to execute on the browser.
args any \ Array Optional. Arguments to pass to the javascript function.

Returns: The return value of the script.

Example(s)

Executing Javascript as function

You can pass the script to execute as a function, and provide the arguments for the function as such:

var value = UI.execute(function () { 
    return 42
}); // value is 42
Executing Javascript as string

You can pass the script to execute as a string.

var value = UI.execute("return 1 + 2"); // value is 3
var value = UI.execute("var i = 42"); // value is `undefined`
Script runs in the browser's context

The script is sent to the browser for execution and has access to variables available to the context of the browsers.

UI.execute(function () { 
    // Runs in the browser's context
    document.title = "Hello world" // Changes the page title to "Hello world"
});

The script cannot access the variables in the context of the test.

var title = "Hello world"
UI.execute(function () { 
    // Runs in the browser's context
    document.title = title // opps, this does not work!
});

To make the previous example work, you can use args to pass variables from the test context to the browser.

var title = "Hello world"
UI.execute(function (title) { 
    // Runs in the browser's context
    document.title = title // Hooray, this will work!
}, title);

If the function takes in more than one argument, you can provide the arguments as an array.

var value = UI.execute(function (a, b) {
    return a + b;
}, [1, 2]); // value is 3
When errors occur

When an error is thrown during the execution of the script, the command results in a test failure, and the value return will be undefined.

var value = UI.execute("throw 'The meaning of life, the universe, and everything.'"); // value is `undefined`