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Monday, July 03, 2006

Unit testing


Good karma for Ruby and for Extreme Programming today.
I've just tried to port libgmp-ruby from handmade testing system to Test::Unit.

It is totally sweet:


#!/usr/bin/ruby

require 'test/unit'
require 'gmp'

class TC_Z < Test::Unit::TestCase
def test_init_null
assert_equal(GMP::Z.new(), 0, "GMP::Z.new() should initialize to 0")
end

def test_init_fixnum
assert_equal(GMP::Z.new(1), 1, "GMP::Z.new(x : Fixnum) should initialize to x")
end

def test_init_z
b = GMP::Z.new(1)
assert_equal(GMP::Z.new(b), b, "GMP::Z.new(x : GMP::Z) should initialize to x")
end

def test_init_string
assert_equal(GMP::Z.new("1"), 1, "GMP::Z.new(x : String) should initialize to x")
end

def test_init_bignum
assert_equal(GMP::Z.new(2**32), 2**32, "GMP::Z.new(x : Bignum) should initialize to x")
end
end


Executing this script runs all the tests:

$ ./unit_tests_1.rb
Loaded suite ./unit_tests_1
Started
.....
Finished in 0.006574 seconds.

5 tests, 5 assertions, 0 failures, 0 errors


Do you see any executable code, any list of tests to run ? Nah, it works by smoke and mirrors. We're going to leave XML BDSM to Java programmers, they seem to like it. ;-)

It even found an actual bug in libgmp-ruby (something was pointing the wrong way around) in the first 5 minutes of testing. That's kinda cool.

You can use multiple assertions per test, fixtures and so on. It still works by magic.


class TC_Q_Basic < Test::Unit::TestCase
def setup
@a=GMP::Q.new(100,11)
@b=GMP::Q.new(200,17)
@c=GMP::Z.new(40)
@d=2**32
end

def test_add
assert_equal(@a + @b, GMP::Q(3900, 187), "GMP::Q should add GMP::Q correctly")
assert_equal(@a + @c, GMP::Q(540, 11), "GMP::Q should add GMP::Z correctly")
assert_equal(@c + @a, GMP::Q(540, 11), "GMP::Z should add GMP::Q correctly")
assert_equal(@a + 2, GMP::Q(122, 11), "GMP::Z should add Fixnum correctly")
assert_equal(@a + @d, GMP::Q(47244640356, 11), "GMP::Z should add Bignum correctly")
assert_equal( 2 + @a, GMP::Q(122, 11), "Fixnum should add GMP::Q correctly")
assert_equal(@d + @a, GMP::Q(47244640356, 11), "Bignum should add GMP::Q correctly")
end
end

3 comments:

Alexey said...

What is the current status of libgmp-ruby? It seems the only available version is 1.0 cached at RAA, all other links are pointing to 0xDEADBEEF.
This library rocks - i've used it to bypass ruby's "warning: in a**b, b may be too big".

Please, publish the recent sources. And a todo list for them too - improving the library seems to be a good Ruby-C task for me. =)

taw said...

Alexey: I'll try to make some publishable version in the next few days.

taw said...

Alexey: I released a tarball. Tell me if you need some help with getting it working.