gistfile1.rb

#Ruby assignment option to assign unless nil

replacement_content = page_contents.content_label_find(item)

##########################################################
# The following is wrong, see http://gist.github.com/68772
##########################################################

# This
element.inner_html = replacement_content if replacement_content

# doesn't do what you expect. It always assigns element.inner_html,
# even if replacement_content is nil.
# It's equivalent to:
b = (a if a)

# If a is nil, the expression (a if a) evaluates to nil, which is assigned to b.

# Also this isn't what you want, but remember that there's &&= as well as ||=.
a = nil # => nil
b = 'lol' # => "lol"
a &&= b # => nil