schnitzel

A high-level DSL for defining arbitrarily complex UI tests

---

Overview

UI tests are generally cumbersome to define and maintain, and even more so to develop usefully complex ones that can serve as both regression tests and development drivers. Schnitzelscript is intended to be a very simple abstraction over Python and webdriver, allowing rapid development of arbitrarily complex UI tests with strong validation, usable by (technical) non- programmers. Here's a quick example that loads a webpage, enters text and clicks a button:

loadpage "https://www.goodeggs.com"
entertext #username "testpassword"
click #submit

As you can see, schnitzelscript comprises commands and 'operands'. Here's a list of common commands:

• loadpage
• click
• entertext
• scroll
• screenshot

Schnitzelscript also understands functions, inasmuch as you can label groups of commands to be executed by named invocation:

define login:
    loadpage "https://www.goodeggs.com"
    entertext #email "sam.wainwright@goodeggs.com"
    entertext #password "testpassword"
    click #submit
    
login()

An important function of UI tests is content/behavior validation. Schnitzelscript provides a number of ways to perform assertions with commands:

login()

assert-pagename is "market"

login()

assert-text #banner is "Welcome!"

Because the real crux of the complexity of UI tests is element identification, which would generally rely on some type of selector derived system and thus require extra work/maintenance on the engineering side, schnitzelscript allows you to identify elements based on content, context or position as well:

entertext input (has-label: "password") "password"
click button (contains-text: "submit")
click button (directly-below: #signup)
click button (color: green, right-of: #logout)
entertext input (directly-below: input (color: green, has-label: "password"))

You can also define variables for reuse throughout scripts. These variables can be strings, numbers, or color hex literals:

let label = "label"
let counter = 1
let red = #0xff0000

Simple control flow constructs also exist to make some complex assertions more simple. You can iterate through elements by using foreach:

foreach input as i:
    entertext i "hello ${i}"

You can also branch conditionally using if statements. If statements can compare two values of the same type, e.g. two strings, two numbers, or two colors.

Schnitzel supports simple moduling for script organization and uses relative filepaths by default. You can also set import paths by setting the SCHNITZ_PATH env var. The loaded modules will execute before the file importing them, so any function names will be available but any top-level commands will also be run:

import ./login.sch
import ./logout.sch as logout  # elect to namespace any imported symbols
import navigate_market.sch  # discovered on SCHNITZ_PATH 

For a complete language specification, see this page.