capybara-webkit evaluate_script vs execute_script

gistfile1.rb

Regarding this article: http://makandracards.com/makandra/12317-capybara-selenium-evaluate_script-might-freeze-your-browser-use-execute_script


code:
puts page.evaluate_script("2+3;").to_i

output:
Started "Evaluate(2+3;)"
Finished "Evaluate(2+3;)" with response "Success(5)"
Wrote response true "5"
5



code:
puts page.execute_script("return 2+3;").to_i;

output:
Started "Execute(return 2+3;)"
undefined|1|SyntaxError: Return statements are only valid inside functions
Finished "Execute(return 2+3;)" with response "Failure({"class":"InvalidResponseError","message":"Javascript failed to execute"})"
Wrote response false "{"class":"InvalidResponseError","message":"Javascript failed to execute"}"


# so presumably you need to wrap it in a self-executing anonymous function like below

code:
puts page.execute_script(%Q{ (function(){ return 2+3; })(); }).to_i;

output:
Started "Execute( (function(){ return 2+3; })(); )"
Finished "Execute( (function(){ return 2+3; })(); )" with response "Success()"
Wrote response true ""
0

# but it still doesn't actually return the value to the surrounding context
# So I'm not seeing the following behavior as mentioned in the article:

page.execute_script("return 2 + 3")
# => 5