OVERVIEW
========

Testable Logger acts as a buffered proxy in front of the normal Logger object
when running in a test environment.  It will store the messages that are logged
during a test run and make them available for testing through the assertions
`assert_logged` and `assert_nothing_logged`.


LOGGING ASSERTIONS
==================

assert_logged
-------------

`assert_logged [level [, match]] [&block]`

Verifies that a message was logged at the given `level`
(:debug, :info, :warn, :error, :fatal or :any [default])
since the last `flush`.  `match` can be a String or a Regexp and if
provided it will be compared against each message logged at the
given level, returning true if it matches and false otherwise.
If a block is given, `match` will be ignored and the block will be
called with an array of message strings as it's only parameter.  The
block should return true for a match and false otherwise.
All parameters are optional: if called with no parameters, it will
pass if anything was logged at any level.


assert\_nothing_logged
----------------------

`assert_nothing_logged [level [, match]] [&block]`

Verifies that a message was not logged at the given `level`.
With no `match` parameter, verifies that nothing was logged at the given
log level.  If `match` is given, verifies that nothing was logged at the
given level that matches the Regexp (if `match` is a Regexp) or is equal to
the String (if `match` is a String).
If a block is given, `match` will be ignored and the block will be called
with an array of message strings as it's only parameter.  The block should
return true for a match and false otherwise.
All parameters are optional: if called with no parameters, it will
only pass if nothing was logged at any level.


USING TESTABLE_LOGGER
=====================

The testable logger will automatically insert itself into your app's logging
mechanism when it is run in the "test" environment.  It will have no effect
on the "development" and "production" environments.  Unless overridden,
testable logger will automatically clear its buffers before each test case.

Here are some ridiculously contrived examples of testable logger's usage:

    class UserTest < Test::Unit::TestCase
	  fixtures  :users
	
	  def test_should_log_error_message
	    # try to find a non-existent user
		u = User.find_by_nickname('Bremelo')
		assert u.nil?
		# make sure an error was logged
		assert_logged :error
	  end
	
	  def test_should_refuse_access_to_sensitive_data
	    # try to look up restricted information
	    a = Address.find_by_last_name_and_manager_id('Alba', users(:crazy_stalker).id)
		assert a.nil?
		# make sure a "Security Violation" error was logged
		assert_logged :error, /Security Violation/
	  end
	
	  def test_should_create_new_user
	    u = User.create(:first_name => 'Bonita', :last_name => 'Applebaum')
	    assert u.gotta_put_me_on
		# make sure no errors were logged
	    assert_nothing_logged :error
	  end
	
	  def test_should_log_more_than_one_warning
	    u = users(:jessep)
	    u.testify
	    assert u.guilty?
	    assert_logged :warn do |messages|
	      count = 0
	      messages_each do |m|
	        case m
	        when /can't handle the truth/ ; count += 1
	        when /need me on that wall/   ; count += 1
	        when /job you sent me to do/  ; count += 1
	        end
	      end
	      count > 1
	    end
	  end
	end

	
OPTIONS
======

Testable Logger hooks into the the setup method of a Test Case and automatically invokes
its `flush` method to clear its internal buffers before each test case.  This feature can
be disabled by setting the instance variable `use_manual_flushing` to `true`.  If you
enable this feature, you will need to call `flush` manually or else the buffers will
retain the logged messages from all previous test cases.


INSTALLATION
============

TestableLogger is a standard Ruby on Rails plugin.  For information about how to install
plugins, type "ruby script/plugin --help" from within a rails project.


KNOWN ISSUES
============

Testable Logger assumes that all Rails objects that use the logger are using the same
Logger object.  If you have a crazy advanced logger setup in your app, this might
cause problems for you.


BUGS, FEEDBACK & PATCHES
========================

Please send any bugs, feedback or (preferably) patches to <[email protected]>.
You can always find the latest information about this plug-in
at <http://github.com/mikedemers/testable-logger/tree>.