First implement

Author: yhirano55

README.md

@@ -1,8 +1,6 @@
 # TraceLocation
 
-Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/trace_location`. To experiment with that code, run `bin/console` for an interactive prompt.
-
-TODO: Delete this and the text above, and describe your gem
+TraceLocation gem provides logs a tracing result of `:call` and `:return`. It's useful for reading the huge codes (e.g. Ruby on Rails) and tracing its process.
 
 ## Installation
 
@@ -22,17 +20,76 @@ Or install it yourself as:
 
 ## Usage
 
-TODO: Write usage instructions here
-
-## Development
+You just surround the code which you want to track the process.
+For example, when you want to track the process of Rails application request/response:
 
-After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
-
-To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
+```
+% bin/rails c
+Running via Spring preloader in process 40741
+Loading development environment (Rails 5.2.3)
+irb(main):001:0> env = Rack::MockRequest.env_for('http://localhost:3000/api/stories')
+irb(main):002:0> TraceLocation.trace { status, headers, body = Rails.application.call(env) }
+Created at /path/to/sampleapp/log/trace_location-2019050105051556706139.log
+=> true
+```
 
-## Contributing
+Then you can get a log like this:
 
-Bug reports and pull requests are welcome on GitHub at https://github.com/yhirano55/trace_location.
+```
+Logged by TraceLocation gem at 2019-05-01 05:22:19 -0500
+https://github.com/yhirano55/trace_location
+
+[Tracing events] C: Call, R: Return
+
+R <internal:prelude>:138#enable
+C /vendor/bundle/gems/railties-5.2.3/lib/rails.rb:39#application
+R /vendor/bundle/gems/railties-5.2.3/lib/rails.rb:41#application
+C /vendor/bundle/gems/railties-5.2.3/lib/rails/engine.rb:522#call
+  C /vendor/bundle/gems/railties-5.2.3/lib/rails/application.rb:607#build_request
+    C /vendor/bundle/gems/railties-5.2.3/lib/rails/engine.rb:705#build_request
+      C /vendor/bundle/gems/railties-5.2.3/lib/rails/application.rb:247#env_config
+      R /vendor/bundle/gems/railties-5.2.3/lib/rails/application.rb:275#env_config
+      C /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/request.rb:59#initialize
+        C /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:40#initialize
+          C /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/url.rb:186#initialize
+            C /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/filter_parameters.rb:34#initialize
+            R /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/filter_parameters.rb:39#initialize
+          R /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/url.rb:190#initialize
+        R /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:43#initialize
+      R /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/request.rb:67#initialize
+      C /vendor/bundle/gems/railties-5.2.3/lib/rails/engine.rb:534#routes
+      R /vendor/bundle/gems/railties-5.2.3/lib/rails/engine.rb:538#routes
+      C /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/request.rb:142#routes=
+        C /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:68#set_header
+        R /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:70#set_header
+      R /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/request.rb:144#routes=
+      C /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:129#script_name
+        C /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:52#get_header
+        R /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:54#get_header
+      R /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:129#script_name
+      C /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/request.rb:150#engine_script_name=
+        C /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/http/request.rb:138#routes
+          C /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:52#get_header
+          R /vendor/bundle/gems/rack-2.0.7/lib/rack/request.rb:54#get_header
+..................
+(an omission)
+..................
+                R /vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/middleware/static.rb:128#call
+                C /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:9#respond_to?
+                  C /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:9#respond_to?
+                    C /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:9#respond_to?
+                      C /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:9#respond_to?
+                        C /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:9#respond_to?
+                        R /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:15#respond_to?
+                      R /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:15#respond_to?
+                    R /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:15#respond_to?
+                  R /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:15#respond_to?
+                R /vendor/bundle/gems/rack-2.0.7/lib/rack/body_proxy.rb:15#respond_to?
+              R /vendor/bundle/gems/rack-2.0.7/lib/rack/sendfile.rb:140#call
+            R /vendor/bundle/gems/railties-5.2.3/lib/rails/engine.rb:525#call
+
+Result: [200, {"Content-Type"=>"application/json; charset=utf-8", "ETag"=>"W/\"42334f8fba25471804e2cfa66fa989a7\"", "Cache-Control"=>"max-age=0, private, must-revalidate", "X-Request-Id"=>"f30153ff-3446-453a-a547-34c4b3766bfc", "X-Runtime"=>"0.455604"}, #<Rack::BodyProxy:0x00007f957960a430 @body=#<Rack::BodyProxy:0x00007f957f1c1f08 @body=#<Rack::BodyProxy:0x00007f957f1a8c10 @body=#<Rack::BodyProxy:0x00007f957f198040 @body=#<Rack::BodyProxy:0x00007f957f17bf58 @body=["[{\"id\":1,\"title\":\"The boy who cried 'wolf!'\",\"parentId\":1},{\"id\":2,\"title\":\"story 2\",\"parentId\":4},{\"id\":3,\"title\":\"story 3\",\"parentId\":null},{\"id\":4,\"title\":\"story 4\",\"parentId\":null},{\"id\":5,\"title\":\"story 1\",\"parentId\":null},{\"id\":6,\"title\":\"story 6\",\"parentId\":null},{\"id\":7,\"title\":\"story 7\",\"parentId\":null},{\"id\":8,\"title\":\"story 8\",\"parentId\":null},{\"id\":9,\"title\":\"story 9\",\"parentId\":null},{\"id\":10,\"title\":\"story 10\",\"parentId\":null},{\"id\":11,\"title\":\"story 11\",\"parentId\":null},{\"id\":12,\"title\":\"story 12\",\"parentId\":null},{\"id\":13,\"title\":\"story 13\",\"parentId\":null}]"], @block=#<Proc:0x00007f957f17ae78@/path/to/sampleapp/vendor/bundle/gems/rack-2.0.7/lib/rack/etag.rb:30>, @closed=false>, @block=#<Proc:0x00007f957f1a2d38@/path/to/sampleapp/vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/middleware/executor.rb:15>, @closed=false>, @block=#<Proc:0x00007f957f1b3728@/path/to/sampleapp/vendor/bundle/gems/railties-5.2.3/lib/rails/rack/logger.rb:39>, @closed=false>, @block=#<Proc:0x00007f957f1c07c0@/path/to/sampleapp/vendor/bundle/gems/activesupport-5.2.3/lib/active_support/cache/strategy/local_cache_middleware.rb:30>, @closed=false>, @block=#<Proc:0x00007f95796096c0@/path/to/sampleapp/vendor/bundle/gems/actionpack-5.2.3/lib/action_dispatch/middleware/executor.rb:15>, @closed=false>]
+```
 
 ## License
 

Rakefile

@@ -1,6 +1,8 @@
-require "bundler/gem_tasks"
-require "rspec/core/rake_task"
+# frozen_string_literal: true
+
+require 'bundler/gem_tasks'
+require 'rspec/core/rake_task'
 
 RSpec::Core::RakeTask.new(:spec)
 
-task :default => :spec
+task default: :spec

bin/console

@@ -1,7 +1,8 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
-require "bundler/setup"
-require "trace_location"
+require 'bundler/setup'
+require 'trace_location'
 
 # You can add fixtures and/or initialization code here to make experimenting
 # with your gem easier. You can also use a different console, if you like.
@@ -10,5 +11,5 @@ require "trace_location"
 # require "pry"
 # Pry.start
 
-require "irb"
+require 'irb'
 IRB.start(__FILE__)

lib/trace_location.rb

@@ -1,6 +1,26 @@
-require "trace_location/version"
+# frozen_string_literal: true
 
-module TraceLocation
-  class Error < StandardError; end
-  # Your code goes here...
+require_relative 'trace_location/version'
+require_relative 'trace_location/config'
+require_relative 'trace_location/tracer'
+
+begin
+  require 'rails'
+  require_relative 'trace_location/railtie'
+rescue LoadError
+  nil
+end
+
+module TraceLocation # :nodoc:
+  def self.trace(options = {}, &block)
+    Tracer.new(options).call(&block)
+  end
+
+  def self.configure
+    yield config
+  end
+
+  def self.config
+    @config ||= Config.new
+  end
 end

lib/trace_location/config.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module TraceLocation
+  class Config # :nodoc:
+    attr_accessor :root_dir, :dest_dir
+
+    def initialize
+      @root_dir = Dir.pwd
+      @dest_dir = Dir.pwd
+    end
+  end
+end

lib/trace_location/railtie.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module TraceLocation
+  class Railtie < ::Rails::Railtie # :nodoc:
+    config.after_initialize do
+      ::TraceLocation.configure do |config|
+        config.root_dir = Rails.root
+        config.dest_dir = Rails.root.join('log')
+      end
+    end
+  end
+end

lib/trace_location/tracer.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+module TraceLocation
+  class Tracer # :nodoc:
+    EVENTS = { call: 'C', return: 'R' }.freeze
+    INDENT_SPACES = 2
+    INDENT_STRING = ' '
+
+    def initialize(options = {})
+      @root_dir = options.fetch(:root_dir) { TraceLocation.config.root_dir }
+      @dest_dir = options.fetch(:dest_dir) { TraceLocation.config.dest_dir }
+    end
+
+    def call(&block)
+      logs = []
+      nest = 0
+      trace_point = TracePoint.new(:call, :return) do |tp|
+        case tp.event
+        when :call
+          logs << build_log(trace_point: tp, nest: nest, root_dir: root_dir)
+          nest += 1
+        when :return
+          nest = nest.positive? ? nest - 1 : 0
+          logs << build_log(trace_point: tp, nest: nest, root_dir: root_dir)
+        end
+      end
+
+      trace_point.enable
+      result = block.call
+      trace_point.disable
+
+      current = Time.now
+      filename = "trace_location-#{current.strftime('%Y%m%d%H%m%s')}.log"
+      file_path = File.join(dest_dir, filename)
+      File.open(file_path, 'w+') do |io|
+        io.puts "Logged by TraceLocation gem at #{current}"
+        io.puts 'https://github.com/yhirano55/trace_location'
+        io.puts
+        io.puts '[Tracing events] C: Call, R: Return'
+        io.puts
+        io.puts logs.join("\n")
+        io.puts
+        io.puts "Result: #{result.inspect}"
+      end
+      $stdout.puts "Created at #{file_path}"
+      true
+    rescue StandardError => e
+      $stdout.puts "Failure: #{e.message}"
+      false
+    ensure
+      trace_point.disable if trace_point.enabled?
+    end
+
+    private
+
+    attr_reader :root_dir, :dest_dir, :block
+
+    def build_log(trace_point:, nest:, root_dir:)
+      indent    = indent(nest)
+      event     = EVENTS[trace_point.event]
+      path      = trace_point.path.to_s.gsub(/#{root_dir}/, '')
+      lineno    = trace_point.lineno
+      method_id = trace_point.method_id
+
+      %(#{indent}#{event} #{path}:#{lineno}##{method_id})
+    end
+
+    def indent(nest)
+      INDENT_STRING * (nest * INDENT_SPACES)
+    end
+  end
+end

lib/trace_location/version.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module TraceLocation
-  VERSION = "0.1.0"
+  VERSION = '0.1.0'
 end

spec/spec_helper.rb

@@ -1,9 +1,11 @@
-require "bundler/setup"
-require "trace_location"
+# frozen_string_literal: true
+
+require 'bundler/setup'
+require 'trace_location'
 
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure
-  config.example_status_persistence_file_path = ".rspec_status"
+  config.example_status_persistence_file_path = '.rspec_status'
 
   # Disable RSpec exposing methods globally on `Module` and `main`
   config.disable_monkey_patching!

spec/trace_location_spec.rb

@@ -1,9 +1,7 @@
+# frozen_string_literal: true
+
 RSpec.describe TraceLocation do
-  it "has a version number" do
+  it 'has a version number' do
     expect(TraceLocation::VERSION).not_to be nil
   end
-
-  it "does something useful" do
-    expect(false).to eq(true)
-  end
 end