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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== IMPORTANT: CrossStub is no longer maintained, use it at your own risk, & expect no bug fixes.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

  1. 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)

  2. 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)

  1. Is there any better serialization strategy instead of the current Marshal load/dump?

== Contacts

Written since 2009 by:

  1. NgTzeYang, contact ngty77[at]gmail[dot]com or http://github.com/ngty

  2. WongLiangZan, contact liangzan[at]gmail[dot]com or http://github.com/liangzan

Released under the MIT license