In many of my tests, I do something along the lines of
assert_match(/foobar/, content)
When the assertion fails, it prints out something resembling the
inspect of the content. In some cases, it's much more readable to print
something different. How do I do that for this one case, but leave the
default behaviour for other cases in the program.
I thought it would be as simple as overriding the inspect method on
content, but that doesn't do the trick.
I've been through the internals of Test::Unit::Assertion, and it seems
to frustrate this effort.
cjs
···
--
Curt Sampson <cjs@cynic.net> +81 90 7737 2974 http://www.starling-software.com
The power of accurate observation is commonly called cynicism
by those who have not got it. --George Bernard Shaw
Never mind, this does actually work if I set it in a different place.
There's some weird thing happening between defining inspect on an object
inside or outside a block to which a custom assert method yields, but I
can't be bothered to debug it.
cjs
···
On Fri, 10 Aug 2007, Curt Sampson wrote:
I thought it would be as simple as overriding the inspect method on
content, but that doesn't do the trick.
--
Curt Sampson <cjs@cynic.net> +81 90 7737 2974 http://www.starling-software.com
The power of accurate observation is commonly called cynicism
by those who have not got it. --George Bernard Shaw
I know you said, "Nevermind," but I wanted to add this bit:
Don't forget about the third parameter to the assert messages. It is
very useful for either giving hints about the meaning of the
assertion, or to diagnose what went wrong, either of which can be
helpful for posterity.
It's important to know that assert_match(pat,obj) essentially matches
`obj.to_s =~ pat`. The output gives the impression that it's matching
`obj.inspect =~ pat`, but that's just sort of an artifact of
AssertionMessage#convert.
Here's some code/output:
require 'test/unit'
class Sampson
def initialize @riddle = '"Out of the eater, something to eat;' +
'out of the strong, something sweet."'
end
class PhilistineTest < Test::Unit::TestCase
def test_quiz
nazirite = Sampson.new
pat = %r/eater/
assert_match(pat, nazirite, "#{nazirite} !~ /#{pat}/")
end
end
end
Loaded suite /home/rking/src/scrap
Started
F
Finished in 0.047188 seconds.
1) Failure:
test_quiz(Sampson::PhilistineTest) [/home/rking/src/scrap.rb:36]:
#<Sampson:0xb7ca2c74> !~ /(?-mix:eater)/.
<#<Sampson:0xb7ca2c74
@riddle=
"\"Out of the eater, something to eat;out of the strong, something
sweet.\"">> expected to be =~
</eater/>.
1 tests, 1 assertions, 1 failures, 0 errors
See that line immediately after the test_quiz(...) line? That's my
custom-provided line. It's kind of buried, but having it is at least
clearer than the lines below, which are a little misleading.
See that line immediately after the test_quiz(...) line? That's my
custom-provided line. It's kind of buried, but having it is at least
clearer than the lines below, which are a little misleading.
When inventing a new assertion - maybe an arbitrarily complex one - you can't leave its user with "nil should not be nil". You should reflect anything you know into the diagnostic. All assertions should take a 'message' field, for the user to add to the explanation.
When a test fails, maximizing the information output helps the user rapidly decide whether to debug the failure, or just revert the code.