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Testable Logger

Enables the use of fragment caching in ActionMailer views.

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.

Resources

• Source: http://github.com/mikedemers/testable-logger
• Support: http://github.com/mikedemers/testable-logger/issues

Installation

script/plugin install git://github.com/mikedemers/testable-logger.git

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.

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.

Usage

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

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.