Increase Selenium tests stability via JavaScript

Igor Khrolhttp://www.khroliz.com

About myself• Igor Khrol• QA Automation Team Lead at

Wargaming• >8 years in test automation• Dozens of projects• Engineer, trainer, consultant,

manager, speaker• Working experience with Selenium

>5 years• My blog: http://en.khroliz.com

Agenda

• Theory and some reasoning• Practical cases

Dependency between testing level and support

Support

Test count

Tech level

UI-tests are unstable

UI-tests are unstable

One of the reasons – modern user interfaces:– Complex– Asynchronous

Modern user interfaces are based on prepared and already made components

Modern user interfaces are based on prepared and already made components

Already made components could be less tested by ourselves

Custom components could be tested separately

Majority of modern UI has internal API

API benefits

• Build to interact with UI components• Synchronous (or there are methods to sync)

1. UI based on already made components2. Already made components could be left

untested or could be tested separately3. Components have its own API4. That API is more reliable than WebDriver API

Use JavaScript API instead of WebDriver

Life example

User interface characteristics:• Lots of frames• ActiveX

Initial solution

driver.findElement(By.id(“fancy-id”)).click();

Browser

WebDriver API

Difficulties

• Interface is very asynchronous, methods work unstably

• Lots of frames (more than five nested) – hard to reach required control

• Impossible to work with ActiveX

Browser Script API

http://docs.oracle.com/cd/B40099_02/books/OIRef/OIRefBrowseScript.html

Browser Script HTTP Server Script

Examples

Final result

• Quick• Reliable• Synchronous

Problems

Synchronous methods and Alert

• Method call is not finished while Alert is not closed

• alert.accept() can’t be called as previous command is not finished yet

window.setTimeout

Lost 100% end user simulation

Other cases for such approach

jQuery based sites - 60%

Synchronization

Convert jQuery objects to WebElement and vise versa

Find elements

Get parent element

Ease interaction with complex elements

Calendar Thanks to @barancev

Custom controls

Custom controls

Common schema

Web Server

Browser

HTTP

Tests

Visible UI

Library

API Components

Core

WebDriver API

WebDriver APIJavaScriptExecutor

Temporary workaround existing WebDriver issues

Workaround wisely

• Only temporary workaround• Important to understand why standard

approach doesn’t work

Summary• Digging into technical details allows writing more

reliable tests• Learning JavaScript and UI-libraries – natural next

step for UI test automation• But we have to understand what we are missing

and find balance

Igor Khrolhttp://en.khroliz.comi_khrol@wargaming.net / khroliz@gmail.com

Thank you!Questions?