cross-stub
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Simple cross process stubbing
= CROSS-STUB makes cross process stubbing possible !!
== IMPORTANT: CrossStub is no longer maintained, use it at your own risk, & expect no bug fixes.
== Introduction
Existing mocking/stubbing frameworks support only stubbing in the current process. This is OK most of the time. However, when running cucumber integration test suite in another process, these in-process stubbing frameworks simply doesn't help. Eg. I want Time.now to always return a timing that should be a Sunday, how do I do that when running cucumber using selenium, culerity, steam, blah, blah driver? It doesn't seem straight-forward me.
(Let's not argue whether stubbing should be encouraged. It is an itch, the poor itch needs to be scratched.)
== Getting Started
It's hosted on gemcutter.org.
$ gem install cross-stub
== Setting Up
=== 1. Rails-3.*
$ rails g cucumber:install $ rails g cross_stub
=== 2. Rails-2.*
$ ./script/generate cucumber $ ./script/generate cross_stub
=== 3. Others (back to basics)
In the test setup method:
CrossStub.setup :file => <CACHE_FILE>
In the test teardown method:
CrossStub.clear
Find an entry point in your target application, eg. in a server, the
point where all request handling starts:
CrossStub.refresh :file => <CACHE_FILE>
For a full list of available cache stores, scroll down to take a look at the 'Cache Stores' section.
== Using It
Cross-stubbing is simple:
=== 1. Simple returning of nil or non-nil value:
==== 1.1. Class method:
class Someone def self.say 'hello' end end
Someone.xstub(:say) Someone.say # yields: nil
Someone.xstub(:say => 'HELLO') Someone.say # yields: 'HELLO'
==== 1.2. Instance method:
Someone.xstub(:say, :instance => true) Someone.new.say # yields: nil
Someone.xstub({:say => 'HELLO'}, :instance => true) Someone.new.say # yields: 'HELLO'
=== 2. If a stubbed method requires argument, pass xstub a proc:
==== 2.1. Class method:
Someone.xstub do def say(something) 'saying "%s"' % something end end
Someone.say('HELLO') # yields: 'saying "HELLO"'
==== 2.2. Instance method:
Someone.xstub(:instance => true) do def say(something) 'saying "%s"' % something end end
Someone.new.say('HELLO') # yields: 'saying "HELLO"'
=== 3. Something more complicated:
something = 'hello' Someone.xstub do def say 'saying "%s"' % something end end
Someone.say # failure !!
The above fails as a result of undefined variable/method 'something', to workaround we can have:
Someone.xstub(:something => 'HELLO') do def say 'saying "%s"' % something end end
Someone.say # yields: 'saying "HELLO"'
== Cache Stores
Cache stores are needed to allow stubs to be made available for different processes. The following describes all cache stores available:
=== 1. File
Setting up (current process)
CrossStub.setup :file => '<CACHE_FILE>'
Refreshing (other process)
CrossStub.refresh :file => '<CACHE_FILE>'
=== 2. Memcache (requires memcache-client gem)
Setting up (current process)
CrossStub.setup :memcache => 'localhost:11211/<CACHE_ID>'
Refreshing (other process)
CrossStub.refresh :memcache => 'localhost:11211/<CACHE_ID>'
=== 3. Redis (requires redis gem)
Setting up (current process)
CrossStub.setup :redis => 'localhost:6379/<CACHE_ID>'
Refreshing (other process)
CrossStub.refresh :redis => 'localhost:6379/<CACHE_ID>'
Adding new store is super easy (w.r.t testing & actual implementation), let me know if u need more :]
== Caveats
-
CrossStub uses ruby's Marshal class to dump & load the stubs, thus it has the same limitations as Marshal (pls note abt a 1.9.1 specific marshal bug at http://redmine.ruby-lang.org/issues/show/3729)
-
Under the hood, CrossStub uses Sourcify (http://github.com/ngty/sourcify) for extracting the methods defined within the proc, u may wish to read Sourcify's gotchas to avoid unnecessary headaches.
== TODO(s)
- Is there any better serialization strategy instead of the current Marshal load/dump?
== Contacts
Written since 2009 by:
-
NgTzeYang, contact ngty77[at]gmail[dot]com or http://github.com/ngty
-
WongLiangZan, contact liangzan[at]gmail[dot]com or http://github.com/liangzan
Released under the MIT license