foobar

.gitignore

@@ -0,0 +1,11 @@
+/.bundle/
+/.yardoc
+/Gemfile.lock
+/_yardoc/
+/coverage/
+/doc/
+/pkg/
+/spec/reports/
+/tmp/
+/email/
+/log/

.rubocop.yml

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+Encoding:
+  Enabled: false
+
+LineLength:
+  Enabled: true
+  Max: 128
+
+Documentation:
+  Enabled: false
+
+MethodLength:
+  Enabled: false

.travis.yml

@@ -0,0 +1,5 @@
+language: ruby
+rvm:
+  - 2.2.3
+before_install: gem install bundler -v 1.10.6
+script: bundle install && bundle exec rake full_build

Gemfile

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+source 'https://rubygems.org'
+
+# Specify your gem's dependencies in demo_logger.gemspec
+gemspec

README.md

@@ -1,2 +1,72 @@
+[![Build Status](https://travis-ci.org/CivJ/demo_logger.svg?branch=zen_hw)](https://travis-ci.org/CivJ/demo_logger)
+
 # demo_logger
-Experimenting with logging features
+
+This logging library layers additional features on top of Ruby's [logger](http://ruby-doc.org/stdlib-2.2.3/libdoc/logger/rdoc/Logger.html)
+
+## Installation
+
+Add this line to your application's Gemfile:
+
+    gem 'demo_logger'
+
+And then execute:
+
+    $ bundle install
+
+Or install it yourself as:
+
+    $ gem install demo_logger
+
+## Building
+See tasks: `bundle exec rake -T`
+
+Full build: `bundle exec rake full_build`
+
+Tests only: `bundle exec rake spec`
+
+## Usage
+
+```
+require 'demo_logger'
+logger = DemoLogger::DemoLogger.new
+```
+
+## Design Overview
+I use a `MultiLogger` class to dispatch messages to `FileLogger`, `StdoutLogger` and `EmailLogger`. Each of these
+classes depends on Ruby's built in `Logger` class. The logic is pretty simple, each class will always relieve all
+the logging calls, but will ignore or execute them according to their configuration. Please see `lib/demo_logger` 
+for the implementation. Tests are located at `spec/`.
+
+
+## Configuration
+
+Configuration is provided via [clean_config](https://github.com/opower/clean_config), an open source library I wrote.
+Please see that project's README for details on how configuration works.
+
+A basic example is
+
+```
+# <your-top-level-project>/config/config.yml <-- this location is required
+:demo_logger:
+  :level: info
+```
+
+## E2E tests
+The tests at `spec/e2e/core/spec/unit` show what happens when you actually include this as a separate library
+into a new project. That is the appropriate location to test config value overrides and 'require' statements. Those
+tests should guarantee this project will work as expected from another project. 
+
+The `Core` project is just a dummy project that depends on `demo-logger`. The only files of interest are:
+
+* spec/e2e/core/lib/core.rb
+* spec/e2e/core/spec/unit/core_spec.rb
+
+## TODOs
+Most of the obvious improvements that I am intentionally omitting are marked with TODO. 
+
+### Other omissions given that this is an interview question
+* Actually sending email: It should be easy to plug this in. Let's talk about it!
+* Integrating with a log aggregator (e.g. Logstash, Splunk)
+* Making everything configurable
+* Aging log files (the underlying library supports this)

Rakefile

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+require 'bundler/gem_tasks'
+require 'rspec/core/rake_task'
+require 'rubocop/rake_task'
+
+RSpec::Core::RakeTask.new(:spec)
+RuboCop::RakeTask.new
+
+namespace :rm do
+  desc 'Remove ./log files'
+  task :log do
+    FileUtils.rm_rf('log')
+  end
+
+  desc 'Remove ./email files'
+  task :email do
+    FileUtils.rm_rf('email')
+  end
+end
+
+desc 'Run style check, tests and build'
+task full_build: [:'rm:log', :'rm:email', :rubocop, :spec, :build]

config/config.yml

@@ -0,0 +1,7 @@
+# debug info log warn severe
+
+:demo_logger:
+  :file: info
+  :stdout: debug
+  :email: severe
+

demo_logger.gemspec

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+# coding: utf-8
+lib = File.expand_path('../lib', __FILE__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+require 'demo_logger/version'
+
+Gem::Specification.new do |spec|
+  spec.name          = 'demo_logger'
+  spec.version       = DemoLogger::VERSION
+  spec.authors       = ['john-crimmins']
+  spec.email         = ['john.crimmins@gmail.com']
+
+  spec.summary       = 'An example logger layered on top of the built in Ruby logger'
+  spec.description   = ''
+  spec.homepage      = 'http://github.com/CivJ/demo_logger'
+  spec.required_ruby_version = '~> 2.2'
+
+  # Prevent pushing this gem to RubyGems.org by setting 'allowed_push_host', or
+  # delete this section to allow pushing this gem to any host.
+  if spec.respond_to?(:metadata)
+    spec.metadata['allowed_push_host'] = 'http://mygemserver.com'
+  else
+    fail 'RubyGems 2.0 or newer is required to protect against public gem pushes.'
+  end
+
+  # rubocop:disable Style/RegexpLiteral
+  spec.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
+  spec.require_paths = ['lib']
+
+  spec.add_runtime_dependency 'clean_config', '= 0.0.2'
+
+  spec.add_development_dependency 'bundler', '~> 1.10'
+  spec.add_development_dependency 'rake', '~> 10.0'
+  spec.add_development_dependency 'should_not', '~> 1.1'
+  spec.add_development_dependency 'rspec', '~> 3.3'
+  spec.add_development_dependency 'rubocop', '= 0.26.0'
+end

lib/demo_logger.rb

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+require_relative 'demo_logger/version'
+require_relative 'demo_logger/multi_logger'
+require_relative 'demo_logger/file_logger'
+require_relative 'demo_logger/stdout_logger'

lib/demo_logger/email_logger.rb

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+require 'logger'
+require 'stringio'
+
+module DemoLogger
+  # TODO: This could share a common superclass with FileLogger
+  # TODO: Sending emails
+  class EmailLogger < Logger
+    attr_reader :email_file
+    attr_accessor :send_mail
+
+    def initialize(level, send_mail = false)
+      log_file_dir = File.expand_path(File.join(Dir.pwd, 'email'))
+      FileUtils.mkdir_p(log_file_dir)
+      log_file_path = File.join(log_file_dir, 'logger.log')
+      @email_file = File.open(File.join(log_file_path), 'a')
+      @send_mail = send_mail
+
+      # We are setting sync = true because of the following line from the spec:
+      # "You need to build a framework that will continuously dump the logger output to a file."
+      # This sounds like an instruction to avoid buffering, so that's what we're doing.
+      # Obvious performance hit.
+      @email_file.sync = true
+      super(@email_file)
+      self.level = level || Logger::WARN
+    end
+  end
+end

lib/demo_logger/file_logger.rb

@@ -0,0 +1,25 @@
+require 'logger'
+require 'clean_config'
+require 'fileutils'
+
+module DemoLogger
+  class FileLogger < Logger
+    attr_accessor :log_file
+
+    # @param level [String] log level for files
+    def initialize(level)
+      log_file_dir = File.expand_path(File.join(Dir.pwd, 'log'))
+      FileUtils.mkdir_p(log_file_dir)
+      log_file_path = File.join(log_file_dir, 'logger.log')
+      @log_file = File.open(File.join(log_file_path), 'a')
+
+      # We are setting sync = true because of the following line from the spec:
+      # "You need to build a framework that will continuously dump the logger output to a file."
+      # This sounds like an instruction to avoid buffering, so that's what we're doing.
+      # Obvious performance hit.
+      @log_file.sync = true
+      super(@log_file)
+      self.level = level || Logger::WARN
+    end
+  end
+end

lib/demo_logger/multi_logger.rb

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+require 'logger'
+require 'clean_config'
+require_relative 'file_logger'
+require_relative 'stdout_logger'
+require_relative 'email_logger'
+
+module DemoLogger
+  class MultiLogger
+    include CleanConfig::Configurable
+    attr_reader :logs
+
+    # TODO: :log and :info are the same. How should #log map onto logger's api?
+    LOGGER_CONST_MAP = {
+      debug: Logger::DEBUG, # 0
+      info: Logger::INFO, # 1
+      log: Logger::INFO,
+      warn: Logger::WARN, # 2
+      severe: Logger::FATAL # 4
+    }
+    FILE = :file
+    STDOUT = :stdout
+    EMAIL = :email
+
+    # @param  config [Hash] config options
+    # @option config [String] :file log level for file
+    # @option config [String] :stdout log level for stdout
+    # @option config [String] :email log level for email
+    def initialize(config = {})
+      defaults = {
+        demo_logger: { file: 'warn', stdout: 'warn', email: 'warn' }
+      }
+      config = defaults.merge(CleanConfig::Configuration.instance).merge(config)
+
+      @logs = {}
+      file_level = config[:demo_logger][:file]
+      stdout_level = config[:demo_logger][:stdout]
+      email_level = config[:demo_logger][:email]
+      @logs[MultiLogger::FILE] = FileLogger.new(translate_level(file_level))
+      @logs[MultiLogger::STDOUT] = StdoutLogger.new(translate_level(stdout_level))
+      @logs[MultiLogger::EMAIL] = EmailLogger.new(translate_level(email_level))
+    end
+
+    # TODO: We could probably clean this repetition up with something clever like Forwardable.
+    def debug(message)
+      @logs.each { |_type, log| log.debug(message) }
+    end
+
+    def info(message)
+      @logs.each { |_type, log| log.info(message) }
+    end
+
+    # TODO: how should we map #log onto Logger's api?
+    def log(message)
+      @logs.each { |_type, log| log.info(message) }
+    end
+
+    def warn(message)
+      @logs.each { |_type, log| log.warn(message) }
+    end
+
+    def severe(message)
+      @logs.each { |_type, log| log.fatal(message) }
+    end
+
+    def close
+      @logs.each { |_type, log| log.close }
+    end
+
+    # rubocop:disable Style/TrailingWhitespace
+
+    private
+
+    def translate_level(level)
+      LOGGER_CONST_MAP[level.downcase.to_sym]
+    end
+
+    def from_config(key)
+      CleanConfig::Configuration.instance[:demo_logger][key]
+    end
+  end
+end

lib/demo_logger/stdout_logger.rb

@@ -0,0 +1,15 @@
+require 'logger'
+
+module DemoLogger
+  class StdoutLogger < Logger
+    # @param level [String] log level for STDOUT
+    def initialize(level)
+      super(STDOUT)
+      self.level = level || Logger::WARN
+    end
+
+    # Don't close STDOUT.
+    def close
+    end
+  end
+end

lib/demo_logger/version.rb

@@ -0,0 +1,3 @@
+module DemoLogger
+  VERSION = '0.1.0'
+end

spec/e2e/core/.gitignore

@@ -0,0 +1,19 @@
+*.gem
+*.rbc
+.bundle
+.config
+.yardoc
+Gemfile.lock
+InstalledFiles
+_yardoc
+coverage
+doc/
+lib/bundler/man
+pkg
+rdoc
+spec/reports
+test/tmp
+test/version_tmp
+tmp
+vendor
+*.log

spec/e2e/core/.rspec

@@ -0,0 +1 @@
+--require spec_helper

spec/e2e/core/.rubocop.yml

@@ -0,0 +1,22 @@
+#do not check for utf stamp
+Encoding:
+  Enabled: false
+
+LineLength:
+  Enabled: true
+  Max: 128
+
+# The rubocop Documentation cop is a duplicate of the Reek IrresponsibleModule
+# check.
+Documentation:
+  Enabled: false
+
+CaseIndentation:
+  Enabled: false
+
+# MethodLength is superseded by Reek's TooManyStatements smell-finder.
+MethodLength:
+  Enabled: false
+
+CyclomaticComplexity:
+  Max: 10

spec/e2e/core/Gemfile

@@ -0,0 +1,5 @@
+source :rubygems
+
+# Specify your gem's dependencies in core.gemspec
+gemspec
+gem 'demo_logger', path: '../../..'

spec/e2e/core/Rakefile

@@ -0,0 +1 @@
+require_relative 'lib/tasks'

spec/e2e/core/config/config.yml

@@ -0,0 +1,4 @@
+:demo_logger:
+    :file: debug
+    :email: debug
+    :stdout: debug