From: "Volkmann, Mark" Date: 2002-10-04T22:43:46+09:00 Subject: assertions in Ruby This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C26BAB.E5DE3580 Content-Type: text/plain; charset="iso-8859-1" Is anyone aware of a Ruby module that adds support for assertions such as what is supported in Java 1.4? I wrote such a thing yesterday and am considering releasing it if I'm not duplicating what someone else has already done. I've included some examples below showing how mine is used. When an assertion fails, a stack trace is output, a message describing the failed assertion is output and execution stops (actually it raises an AssertionError which typically would not be caught). This is primarily for use during initial development of new code. Assertions are disabled by default. To enable them, the global variable $enable_assertions must be set to true (Should I use some other mechanism besides a global variable to do this?). Even when assertions are disabled, they provide good documentation on what your code expects. --- require 'Assertions' $enable_assertions = true # Assert that the value of temperature is in the range 0 to 100. # The first parameter is the condition to be tested (should evaluate to true or false) # and the last parameter is a description of what is being asserted. assert((0..100).include?(temperature), "valid temperature returned") # Assert that the object wsdl responds to the messages "proxy" and "service". # The first parameter is the value to be tested and the remaining parameters # are any number of symbols referring to messages. assert_responds(wsdl, :proxy, :service) # Assert that the object currently referred to by operationName is a kind of String. # The first parameter is the value to be tested and the # remaining parameters are the allowed types for the value. assert_type(operationName, String, QName) # Assert that localName is a kind of String, namespace is a kind of String and # prefix is either a kind of String or is nil. # Each parameter is an array containing a value to be tested # and the types allowed for that value. # NilClass is used to specify that a value can be nil. assert_types([localName, String], [namespace, String], [prefix, String, NilClass]) I understand all the debate over whether checking types in Ruby code is a good idea. Even if you decide not to use assert_responds, assert_type and assert_types, using just the assert method to test certain conditions is useful on its own. *********************************************************************************** WARNING: All e-mail sent to and from this address will be received or otherwise recorded by the A.G. Edwards corporate e-mail system and is subject to archival, monitoring or review by, and/or disclosure to, someone other than the recipient. ************************************************************************************ ------_=_NextPart_001_01C26BAB.E5DE3580 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable assertions in Ruby

Is anyone aware of a Ruby module that adds support for as= sertions such as what is supported in Java 1.4?  I wrote such a thing = yesterday and am considering releasing it if I'm not duplicating what someo= ne else has already done.

I've included some examples below showing how mine is use= d.

When an assertion fails, a stack trace is output, a messa= ge describing the failed assertion is output and execution stops (actually = it raises an AssertionError which typically would not be caught).  Thi= s is primarily for use during initial development of new code.  Assert= ions are disabled by default.  To enable them, the global variable $en= able_assertions must be set to true (Should I use some other mechanism besi= des a global variable to do this?).  Even when assertions are disabled= , they provide good documentation on what your code expects.

---

require 'Assertions'

$enable_assertions =3D true

# Assert that the value of temperature is in the range 0 = to 100.
# The first parameter is the condition to be tested (sho= uld evaluate to true or false)
# and the last parameter is a description of what is bei= ng asserted.
assert((0..100).include?(temperature), "valid tempe= rature returned")

# Assert that the object wsdl responds to the messages &q= uot;proxy" and "service".
# The first parameter is the value to be tested and the = remaining parameters
# are any number of symbols referring to messages.
assert_responds(wsdl, :proxy, :service) 

# Assert that the object currently referred to by operati= onName is a kind of String.
# The first parameter is the value to be tested and the<= /FONT>
# remaining parameters are the allowed types for the val= ue.
assert_type(operationName, String, QName)

# Assert that localName is a kind of String, namespace is= a kind of String and
# prefix is either a kind of String or is nil.
# Each parameter is an array containing a value to be te= sted
# and the types allowed for that value.
# NilClass is used to specify that a value can be nil.
assert_types([localName, String],
         &n= bsp;   [namespace, String],
         &n= bsp;   [prefix, String, NilClass])

I understand all the debate over whether checking types i= n Ruby code is a good idea.  Even if you decide not to use assert_resp= onds, assert_type and assert_types, using just the assert method to test ce= rtain conditions is useful on its own.



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