Attractive Ruby tests that use multi-line strings
Attractive Ruby tests that use multi-line strings
Submitted by Brian Marick's blog on Wed, 16/11/2005 - 14:07.Suppose you're testing some method whose input is a multi-line string. You could write something like this:
def test_tags_can_be_deeply_nested table = "<table> <tr><td> <table> <tr> <td> <table> <tr> <td> Way nested </td> </tr> </table> </td> </tr> </table> </td></tr> </table>" slices = TagSlices.new(table, "table") # blah blah blah end |
That's fine - unless whitespace in the middle of the string is significant. The above method has no whitespace on the string's first line, but a whole lot on the others. What if I needed it all to be flush left? This is ugly:
def test_tags_can_be_deeply_nested table ="<table> <tr><td> <table> <tr> <td> <table> <tr> <td> Way nested </td> </tr> </table> </td> </tr> </table> </td></tr> </table>" slices = TagSlices.new(table, "table") # blah blah blah end |
I could argue that the ugliness makes it too hard to see the structure of the test and too hard to skim a file quickly and see what the tests are. That argument may even be true, but the real reason I don't like it is that it's ugly.
So I write such tests like this:
def test_tags_can_be_deeply_nested table = "<table> . <tr><td> . <table> . <tr> . <td> . <table> . <tr> . <td> . Way nested . </td> . </tr> . </table> . </td> . </tr> . </table> . . </td></tr> .</table>".unindent slices = TagSlices.new(table, "table") # blah blah blah end |
unindent removes the whitespace at the beginnings of lines, together with the discrete margin made of dots. Its code looks like this:
class String def unindent gsub(/^\s*\./m, '') endend |
I've fiddled around with unindent to a ridiculous degree, changing its name, how it works, how the margin is indicated. I think I've settled on this one.