Can execute JS function in the browser at KarateDriver? - karate

Question

When using KarateDriver, I want to define and execute JS function in the browser.
Is is possible?
I want to define it like:
* def someFn =
"""
function(param) {
// DOM operation in the browser
// Event handling in the browser
return
}
"""
* assert someFn('param1') == '<span>param1</span>'
Edit1:
I define and execute;
* def keyword = 'karate'
* def formSubmit =
"""
function(formId) {
var formElem = document.getElementById(formId);
formElem.submit();
}
"""
Given driver 'https://github.com/search'
And driver.input('input[name=q]', keyword)
When driver.eval(formSubmit('search_form'))
Then eval driver.waitUntil(driver.location == 'https://github.com/search?utf8=%E2%9C%93&q=' + keyword + '&ref=simplesearch')
but this feature is failure.
javascript evaluation failed: driver.eval(formSubmit('search_form')), ReferenceError: "document" is not defined in <eval> at line number 2
Can it use DOM operations?
Edit2:
I can define and execute the JS function:
* def getSubmitFn =
"""
function(formId) {
return "var formElem = document.getElementById('" + formId + "');"
+ "formElem.submit();"
}
"""

Answer 1

You can do driver.eval() where the argument is raw javascript code as a string. I think this is sufficient for your needs:
* match driver.eval("location.href") == webUrlBase + '/page-01'
* assert driver.eval('1 + 2') == 3
EDIT: the JS engine for Karate and the Browser JS engine is different and there is no connection. So you have to pass JS as raw strings to driver.eval() here is an example that works for submitting a form.
* def getSubmitFn =
"""
function(formId) {
return "document.getElementById('" + formId + "').submit()"
}
"""
* def temp = getSubmitFn('eg02FormId')
* print temp
* driver.eval(temp)
EDIT: I just remembered, * driver.eval() is valid, no need to do * eval karate.eval()
Typically what you pass to driver.eval() can be simple, but it has to be a string, and you cannot use Karate variables (you have to hard-code them when creating the JS dynamically). You can use DOM objects and functions. You can have multiple statements of JS separated by ;.