Puts Debuggerer 1.0.1

Debugger-less Debugging FTW

Featured in State of the Art Rails 2023 Edition

(credit to Aaron Patterson for partial inspiration: https://tenderlovemaking.com/2016/02/05/i-am-a-puts-debuggerer.html)

If you like Awesome_Print (or Amazing_Print), you will love Puts Debuggerer (which builds upon them)!

Debuggers are great! They help us troubleshoot complicated programming problems by inspecting values produced by code, line by line. They are invaluable when trying to understand what is going on in a large application composed of thousands or millions of lines of code.

In day-to-day test-driven development and simple app debugging though, a puts statement can be a lot quicker in revealing what is going on than halting execution completely just to inspect a single value or a few. This is certainly true when writing the simplest possible code that could possibly work, and running a test every few seconds or minutes. Still, there are a number of problems with puts debugging, like difficulty in locating puts statements in a large output log, knowing which files, line numbers, and methods the puts statements were invoked from, identifying which variables were printed, and seeing the content of structured hashes and arrays in an understandable format.

Enter puts_debuggerer! A guilt-free puts debugging Ruby gem FTW that prints file names, line numbers, class names, method names, code statements, headers, footers, and stack traces; and formats output nicely courtesy of awesome_print (or amazing_print if you prefer).

puts_debuggerer automates tips mentioned in this blog post by Aaron Patterson using the pd method available everywhere after requiring the gem.

Basic Example:

# /Users/User/trivia_app.rb      # line 1
require 'pd'                     # line 2
class TriviaApp                  # line 3
  def question                   # line 4
    bug_or_band = 'Beatles'      # line 5
    pd bug_or_band               # line 6
  end                            # line 7
end                              # line 8
TriviaApp.new.question           # line 9

Output:

[PD] /Users/User/trivia_app.rb:6 in TriviaApp.question
   > pd bug_or_band               # line 6
  => "Beatles"

pd revealed that the variable contains the band name "Beatles" not the bug "Beetle", in addition to revealing the printed code statement pd bug_or_band, the file name /Users/User/trivia_app.rb, the line number 6, the class name TriviaApp, and the method name question.

Background

It can be quite frustrating to lose puts statements in a large output or log file. One way to help find them is add an announcer (e.g. puts "The Order Total") or a header (e.g. puts '>'*80) before every puts statement. Unfortunately, that leads to repetitive wasteful effort that adds up quickly over many work sessions and interrupts thinking flow while solving problems.

puts_debuggerer automates that work via the short and simple pd command, automatically printing meaningful headers for output and accelerating problem solving work due to ease of typing.

Example without pd:

puts order_total

Output:

195.50

Which gets lost in a logging stream such as:

   (2.7ms)  CREATE TABLE "ar_internal_metadata" ("key" character varying PRIMARY KEY, "value" character varying, "created_at" timestamp NOT NULL, "updated_at" timestamp NOT NULL)
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
  SQL (0.3ms)  INSERT INTO "ar_internal_metadata" ("key", "value", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "key"  [["key", "environment"], ["value", "development"], ["created_at", 2017-08-24 22:56:52 UTC], ["updated_at", 2017-08-24 22:56:52 UTC]]
   (0.3ms)  COMMIT
   195.50
  ActiveRecord::InternalMetadata Load (0.3ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
   (0.2ms)  COMMIT

Here is a simple example using pd instead, which provides everything the puts statements above provide in addition to deducing the file name, line number, class name, and method name automatically for dead-easy debugging:

pd order_total

Output:

    (2.7ms)  CREATE TABLE "ar_internal_metadata" ("key" character varying PRIMARY KEY, "value" character varying, "created_at" timestamp NOT NULL, "updated_at" timestamp NOT NULL)
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
  SQL (0.3ms)  INSERT INTO "ar_internal_metadata" ("key", "value", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "key"  [["key", "environment"], ["value", "development"], ["created_at", 2017-08-24 22:56:52 UTC], ["updated_at", 2017-08-24 22:56:52 UTC]]
   (0.3ms)  COMMIT
[PD] /Users/User/ordering/order.rb:39 in Order.calculate_order_total
  > pd order_total
 => 195.50
  ActiveRecord::InternalMetadata Load (0.3ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
   (0.2ms)  COMMIT

This is not only easy to locate in a logging stream such as the one below, but also announces the order_total variable with [PD] for easy findability among other pd statements (you may always enter [PD] or variable name order_total using the CMD+F Quick Find to instantly jump to that line in the log):

pd order_total
pd order_summary
pd order_details

Output:

   (2.7ms)  CREATE TABLE "ar_internal_metadata" ("key" character varying PRIMARY KEY, "value" character varying, "created_at" timestamp NOT NULL, "updated_at" timestamp NOT NULL)
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
[PD] /Users/User/ordering/order.rb:39 in Order.calculate_order_total
  > pd order_total
 => 195.50
   (0.2ms)  BEGIN
  SQL (0.3ms)  INSERT INTO "ar_internal_metadata" ("key", "value", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "key"  [["key", "environment"], ["value", "development"], ["created_at", 2017-08-24 22:56:52 UTC], ["updated_at", 2017-08-24 22:56:52 UTC]]
   (0.3ms)  COMMIT
[PD] /Users/User/ordering/order.rb:40 in Order.calculate_order_total
  > pd order_summary
 => "Pragmatic Ruby Book"
  ActiveRecord::InternalMetadata Load (0.3ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
   (0.2ms)  COMMIT
[PD] /Users/User/ordering/order.rb:41 in Order.calculate_order_total
  > pd order_details
 => "[Hard Cover] Pragmatic Ruby Book - English Version"

What if you would like to add a header for faster findability of groups of related pd statements? Just use the header option:

pd order_total, header: true
pd order_summary
pd order_details

Or the h shortcut:

pd order_total, h: :t
pd order_summary
pd order_details

Output:

   (2.7ms)  CREATE TABLE "ar_internal_metadata" ("key" character varying PRIMARY KEY, "value" character varying, "created_at" timestamp NOT NULL, "updated_at" timestamp NOT NULL)
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[PD] /Users/User/ordering/order.rb:39 in Order.calculate_order_total
  > pd order_total, header: true
 => 195.50
   (0.2ms)  BEGIN
  SQL (0.3ms)  INSERT INTO "ar_internal_metadata" ("key", "value", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "key"  [["key", "environment"], ["value", "development"], ["created_at", 2017-08-24 22:56:52 UTC], ["updated_at", 2017-08-24 22:56:52 UTC]]
   (0.3ms)  COMMIT
[PD] /Users/User/ordering/order.rb:40 in Order.calculate_order_total
  > pd order_summary
 => "Pragmatic Ruby Book"
  ActiveRecord::InternalMetadata Load (0.3ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
   (0.2ms)  COMMIT
[PD] /Users/User/ordering/order.rb:41 in Order.calculate_order_total
  > pd order_details
 => "[Hard Cover] Pragmatic Ruby Book - English Version"

Wanna add a footer too? No problem!

pd order_total, header: true
pd order_summary
pd order_details, footer: true

Or use the f shortcut:

pd order_total, h: :t
pd order_summary
pd order_details, f: :t

Output:

   (2.7ms)  CREATE TABLE "ar_internal_metadata" ("key" character varying PRIMARY KEY, "value" character varying, "created_at" timestamp NOT NULL, "updated_at" timestamp NOT NULL)
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
################################################################################
[PD] /Users/User/ordering/order.rb:39 in Order.calculate_order_total
  > pd order_total, header: '>'*80
 => 195.50
   (0.2ms)  BEGIN
  SQL (0.3ms)  INSERT INTO "ar_internal_metadata" ("key", "value", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "key"  [["key", "environment"], ["value", "development"], ["created_at", 2017-08-24 22:56:52 UTC], ["updated_at", 2017-08-24 22:56:52 UTC]]
   (0.3ms)  COMMIT
[PD] /Users/User/ordering/order.rb:40 in Order.calculate_order_total
  > pd order_summary
 => "Pragmatic Ruby Book"
  ActiveRecord::InternalMetadata Load (0.3ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
   (0.2ms)  COMMIT
[PD] /Users/User/ordering/order.rb:41 in Order.calculate_order_total
  > pd order_details, footer: '<'*80
 => "[Hard Cover] Pragmatic Ruby Book - English Version"
################################################################################

Need a quick stack trace? Just use the caller option (you may surround with header and footer too via wrapper).

pd order_total, caller: true, wrapper: true
pd order_summary
pd order_details

Or use the c and w shortcuts:

pd order_total, c: :t, w: :t
pd order_summary
pd order_details

Output:

   (2.7ms)  CREATE TABLE "ar_internal_metadata" ("key" character varying PRIMARY KEY, "value" character varying, "created_at" timestamp NOT NULL, "updated_at" timestamp NOT NULL)
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
********************************************************************************
[PD] /Users/User/ordering/order.rb:39 in Order.calculate_order_total
  > pd order_total, caller: true, wrapper: true
 => 195.50
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/activesupport-5.2.4.3/lib/active_support/dependencies.rb:291:in `block in require'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/activesupport-5.2.4.3/lib/active_support/dependencies.rb:257:in `load_dependency'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/activesupport-5.2.4.3/lib/active_support/dependencies.rb:291:in `require'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/railties-5.2.4.3/lib/rails/commands/server/server_command.rb:145:in `block in perform'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/railties-5.2.4.3/lib/rails/commands/server/server_command.rb:142:in `tap'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/railties-5.2.4.3/lib/rails/commands/server/server_command.rb:142:in `perform'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/thor-1.0.1/lib/thor/command.rb:27:in `run'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/thor-1.0.1/lib/thor/invocation.rb:127:in `invoke_command'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/thor-1.0.1/lib/thor.rb:392:in `dispatch'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/railties-5.2.4.3/lib/rails/command/base.rb:69:in `perform'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/railties-5.2.4.3/lib/rails/command.rb:46:in `invoke'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/railties-5.2.4.3/lib/rails/commands.rb:18:in `<main>'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require_with_bootsnap_lfi'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:31:in `require'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/activesupport-5.2.4.3/lib/active_support/dependencies.rb:291:in `block in require'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/activesupport-5.2.4.3/lib/active_support/dependencies.rb:257:in `load_dependency'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/activesupport-5.2.4.3/lib/active_support/dependencies.rb:291:in `require'
     /Users/User/code/sample-glimmer-dsl-opal-rails5-app/bin/rails:9:in `<top (required)>'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in `load'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in `call'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/spring-2.1.0/lib/spring/client/command.rb:7:in `call'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/spring-2.1.0/lib/spring/client.rb:30:in `run'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/spring-2.1.0/bin/spring:49:in `<top (required)>'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/spring-2.1.0/lib/spring/binstub.rb:11:in `load'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/spring-2.1.0/lib/spring/binstub.rb:11:in `<top (required)>'
     /Users/User/code/sample-glimmer-dsl-opal-rails5-app/bin/spring:15:in `require'
     /Users/User/code/sample-glimmer-dsl-opal-rails5-app/bin/spring:15:in `<top (required)>'
     bin/rails:3:in `load'
     bin/rails:3:in `<main>'
********************************************************************************
   (0.2ms)  BEGIN
  SQL (0.3ms)  INSERT INTO "ar_internal_metadata" ("key", "value", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "key"  [["key", "environment"], ["value", "development"], ["created_at", 2017-08-24 22:56:52 UTC], ["updated_at", 2017-08-24 22:56:52 UTC]]
   (0.3ms)  COMMIT
[PD] /Users/User/ordering/order.rb:40 in Order.calculate_order_total
  > pd order_summary
 => "Pragmatic Ruby Book"
  ActiveRecord::InternalMetadata Load (0.3ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
   (0.2ms)  COMMIT
[PD] /Users/User/ordering/order.rb:41 in Order.calculate_order_total
  > pd order_details
 => "[Hard Cover] Pragmatic Ruby Book - English Version"

Is the stack trace too long? Shorten it by passing number of lines to display to caller option.

pd order_total, caller: 3, wrapper: true
pd order_summary
pd order_details

Or use shortcut syntax:

pd order_total, c: 3, w: :t
pd order_summary
pd order_details

   (2.7ms)  CREATE TABLE "ar_internal_metadata" ("key" character varying PRIMARY KEY, "value" character varying, "created_at" timestamp NOT NULL, "updated_at" timestamp NOT NULL)
  ActiveRecord::InternalMetadata Load (0.4ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
********************************************************************************
[PD] /Users/User/ordering/order.rb:39 in Order.calculate_order_total
  > pd order_total, caller: 3, wrapper: true
 => 195.50
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `require'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:23:in `block in require_with_bootsnap_lfi'
     /Users/User/.rvm/gems/ruby-2.7.1/gems/bootsnap-1.4.6/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
********************************************************************************
   (0.2ms)  BEGIN
  SQL (0.3ms)  INSERT INTO "ar_internal_metadata" ("key", "value", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "key"  [["key", "environment"], ["value", "development"], ["created_at", 2017-08-24 22:56:52 UTC], ["updated_at", 2017-08-24 22:56:52 UTC]]
   (0.3ms)  COMMIT
[PD] /Users/User/ordering/order.rb:40 in Order.calculate_order_total
  > pd order_summary
 => "Pragmatic Ruby Book"
  ActiveRecord::InternalMetadata Load (0.3ms)  SELECT  "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2  [["key", :environment], ["LIMIT", 1]]
   (0.2ms)  BEGIN
   (0.2ms)  COMMIT
[PD] /Users/User/ordering/order.rb:41 in Order.calculate_order_total
  > pd order_details
 => "[Hard Cover] Pragmatic Ruby Book - English Version"

There are many more options and features in puts_debuggerer as detailed below.

Instructions

Option 1: Bundler

This is the recommended way for installing in Rails apps in addition to configuring the app_path option.

Add the following to bundler's Gemfile (in Rails, you can optionally limit to the :development and :test groups).

gem 'puts_debuggerer', '~> 1.0.1'

Run:

bundle

Optionally, you may configure the Rails initializer config/initializers/puts_debuggerer_options.rb with further customizations as per the Options section below.

Also, you may want to add the following to the initializer too if you limited the puts_debuggerer gem to the :development and :test groups:

unless Rails.env.development? || Rails.env.test?
  def pd(*args, &block) # `pd(...)` in Ruby 2.7+
    # No Op (just a stub in case developers forget troubleshooting pd calls in the code and deploy to production)
  end
end

The Rails config.log_level is assumed to be :debug. If you have it set to something else like :info, then you need to update PutsDebuggerer.printer to print at a different log level (e.g. :info) by adding the following code to the initializer above (this code is a modification of the default at PutsDebuggerer::PRINTER_RAILS):

PutsDebuggerer.printer = lambda do |output| 
  puts output if Rails.env.test?
  Rails.logger.info(output)  
end

Option 2: Manual

Or manually install and require library.

gem install puts_debuggerer -v1.0.1

require 'puts_debuggerer'

Or the shorter form (often helpful to quickly troubleshoot an app):

require 'pd'

Awesome Print

puts_debuggerer comes with awesome_print.

It is the default PutsDebuggerer.print_engine

Still, if you do not need it, you may disable by setting PutsDebuggerer.print_engine to another value. Example:

PutsDebuggerer.print_engine = :puts

If you also avoid requiring 'awesome_print', PutsDebuggerer will NOT require it either if it sees that you have a different print_engine. In fact, you may switch to another print engine if you prefer like amazing_print as explained here.

You may also avoid requiring in Bundler Gemfile with require: false:

gem "awesome_print", require: false
gem "puts_debuggerer"

Usage

First, add pd method anywhere in your code to display details about an object or expression (if you're used to awesome_print, you're in luck! puts_debuggerer includes awesome_print (or amazing_print if preferred) as the default print engine for output).

Example:

# /Users/User/trivia_app.rb      # line 1
require 'pd'                     # line 2
class TriviaApp                  # line 3
  def question                   # line 4
    bug_or_band = 'Beatles'      # line 5
    pd bug_or_band               # line 6
  end                            # line 7
end                              # line 8
TriviaApp.new.question           # line 9

Output:

[PD] /Users/User/trivia_app.rb:6 in TriviaApp.question
   > pd bug_or_band               # line 6
  => "Beatles"

In addition to the object/expression output, you get to see the source file name, line number, class name, method name, and source code to help you debug and troubleshoot problems quicker (it even works in IRB).

You can use pd at the top-level main object too, and it prings Object.<main> for the class/method.

Example:

# /Users/User/finance_calculator_app/pd_test.rb           # line 1
bug = 'Beetle'                                            # line 2
pd "Show me the source of the bug: #{bug}"                # line 3
pd "Show me the result of the calculation: #{(12.0/3.0)}" # line 4

Output:

[PD] /Users/User/finance_calculator_app/pd_test.rb:3 in Object.<main>
   > pd "Show me the source of the bug: #{bug}"
  => "Show me the source of the bug: Beetle"
[PD] /Users/User/finance_calculator_app/pd_test.rb:4 in Object.<main>
   > pd "Show me the result of the calculation: #{(12.0/3.0)}"
  => "Show me the result of the calculation: 4.0"

Second, quickly locate printed lines using the Find feature (e.g. CTRL+F) by looking for:

[PD]
file:line_number
class.method
known ruby expression.

Third, easily remove your pd statements via the source code Find feature once done debugging.

Note that pd returns the passed in object or expression argument unchanged, permitting debugging with shorter syntax than tap, and supporting chaining of extra method invocations afterward.

Example:

# /Users/User/greeting_app/pd_test.rb                     # line 1
name = 'Robert'                                           # line 2
greeting = "Hello #{pd(name)}"                            # line 3

Output:

[PD] /Users/User/greeting_app/pd_test.rb:3 in Object.<main>
   > greeting = "Hello #{pd(name)}"
  => "Hello Robert"

Happy puts_debuggerering!

`pd_inspect` kernel method

You may want to just return the string produced by the pd method without printing it.

In that case, you may use the pd alternative to object.inspect:

object.pd_inspect
obj.pdi (shorter alias)

This returns the pd formatted string without printing to the terminal or log files.

Ruby Logger and Logging::Logger

Ruby Logger and Logging::Logger (from logging gem) are supported as printers (learn more under PutsDebuggerer#printer).

Options

Options enable more data to be displayed with puts_debuggerer, such as the caller backtrace, header, and footer. They also allow customization of output format.

Options can be set as a global configuration or piecemeal per puts statement.

Global configuration is done via PutsDebuggerer module attribute writers. On the other hand, piecemeal options can be passed to the pd global method as the second argument.

Example 1:

# File Name: /Users/User/project/piecemeal.rb
data = [1, [2, 3]]
pd data, header: true

Prints out:

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[PD] /Users/User/project/piecemeal.rb:3 in Object.<main>
   > pd data, header: true
  => [1, [2, 3]]

Example 2:

# File Name: /Users/User/project/piecemeal.rb
data = [1, [2, 3]]
pd data, header: '>'*80, footer: '<'*80, announcer: "   -<[PD]>-\n  "

Prints out:

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
   -<[PD]>-
   /Users/User/project/piecemeal.rb:3 in Object.<main>
   > pd data, header: '>'*80, footer: '<'*80, announcer: "   -<[PD]>-\n  "
  => [1, [2, 3]]
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Details about all the available options are included below.

`PutsDebuggerer.app_path`

(default = nil)

Sets absolute application path. Makes pd file path output relative to it.

In Rails, you can add the following code to a config/initializers/puts_debuggerer_options.rb file to make all output relative to Rails application path:

PutsDebuggerer.app_path = Rails.root.to_s

Example:

# /Users/User/finance_calculator_app/pd_test.rb                                 # line 1
PutsDebuggerer.app_path = File.join('/Users', 'User', 'finance_calculator_app') # line 2
bug = 'Beetle'                                                                  # line 3
pd "Show me the source of the bug: #{bug}"                                      # line 4

Example Printout:

[PD] /pd_test.rb:4 in Object.<main>
   > pd "Show me the source of the bug: #{bug}"
  => "Show me the source of the bug: Beetle"

`PutsDebuggerer.header`

(default = '>'*80) [shortcut: h]

Header to include at the top of every print out.

Default value is nil
Value true enables header as '>'*80
Value false, nil, or empty string disables header
Any other string value gets set as a custom header

Example:

pd (x=1), header: true

Prints out:

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[PD] /Users/User/example.rb:1 in Object.<main>
   > pd (x=1), header: true
  => "1"

Shortcut Example:

pd (x=1), h: :t

Prints out:

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[PD] /Users/User/example.rb:1 in Object.<main>
   > pd (x=1), h: :t
  => "1"

Global Option Example:

PutsDebuggerer.header = true
pd (x=1)
pd (x=2)

Prints out:

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[PD] /Users/User/example.rb:2 in Object.<main>
   > pd (x=1)
  => "1"
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[PD] /Users/User/example.rb:3 in Object.<main>
   > pd (x=2)
  => "2"

`PutsDebuggerer.footer`

(default = '<'*80) [shortcut: f]

Footer to include at the bottom of every print out.

Default value is nil
Value true enables footer as '<'*80
Value false, nil, or empty string disables footer
Any other string value gets set as a custom footer

Example:

pd (x=1), footer: true

Prints out:

[PD] /Users/User/example.rb:1 in Object.<main>
   > pd (x=1), footer: true
  => "1"
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Shortcut Example:

pd (x=1), f: :t

Prints out:

[PD] /Users/User/example.rb:1 in Object.<main>
   > pd (x=1), f: :t
  => "1"
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Global Option Example:

PutsDebuggerer.footer = true
pd (x=1)
pd (x=2)

Prints out:

[PD] /Users/User/example.rb:2 in Object.<main>
   > pd (x=1)
  => "1"
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
[PD] /Users/User/example.rb:3 in Object.<main>
   > pd (x=2)
  => "2"
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

`PutsDebuggerer.wrapper`

(default = '*'*80) [shortcut: w]

Wrapper to include at the top and bottom of every print out (both header and footer).

Default value is nil
Value true enables wrapper as '*'*80
Value false, nil, or empty string disables wrapper
Any other string value gets set as a custom wrapper

Example:

pd (x=1), wrapper: true

Prints out:

********************************************************************************
[PD] /Users/User/example.rb:1 in Object.<main>
   > pd x=1, wrapper: true
  => "1"
********************************************************************************

Shortcut Example:

pd (x=1), w: :t

Prints out:

********************************************************************************
[PD] /Users/User/example.rb:1 in Object.<main>
   > pd x=1, w: :t
  => "1"
********************************************************************************

Global Option Example:

PutsDebuggerer.wrapper = true
pd (x=1)
pd (x=2)

Prints out:

********************************************************************************
[PD] /Users/User/example.rb:2 in Object.<main>
   > pd (x=1)
  => "1"
********************************************************************************
********************************************************************************
[PD] /Users/User/example.rb:3 in Object.<main>
   > pd (x=2)
  => "2"
********************************************************************************

`PutsDebuggerer.source_line_count`

(default = 1)

Prints multiple source code lines as per count specified. Useful when a statement is broken down on multiple lines or when there is a need to get more context around the line printed.

Example:

pd (true ||
  false), source_line_count: 2

Prints out:

[PD] /Users/User/example.rb:1 in Object.<main>
   > pd (true ||
       false), source_line_count: 2
  => "true"

Example:

PutsDebuggerer.source_line_count = 2 # setting via global option
pd (true ||
  false)

Prints out:

[PD] /Users/User/example.rb:2 in Object.<main>
   > pd (true ||
       false), source_line_count: 2
  => "true"

`PutsDebuggerer.printer`

(default = :puts)

Printer is a global method symbol, lambda expression, or logger to use in printing to the user.

Examples of a global method are :puts and :print. An example of a lambda expression is lambda {|output| Rails.logger.info(output)} Examples of a logger are a Ruby Logger instance or Logging::Logger instance

When a logger is supplied, it is automatically enhanced with a PutsDebuggerer formatter to use when calling logger methods outside of PutsDebuggerer (e.g. logger.error('msg') will use pd)

Printer may be set to false to avoid printing and only return the formatted string. It is equivalent of just calling .pd_inspect (or alias .pdi) on the object

Defaults to :puts In Rails, it defaults to:

lambda do |output|
  puts output if Rails.env.test?
  Rails.logger.debug(output)
end

Example of adding the following code to config/initializers/puts_debuggerer_options.rb:

# File Name: /Users/user/railsapp/config/initializers/puts_debuggerer_options.rb
PutsDebuggerer.printer = lambda do |output|
  puts output
end
str = "Hello"
pd str

Prints out the following in standard out stream only (not in log files):

[PD] /Users/user/railsapp/config/initializers/puts_debuggerer_options.rb:6
   > pd str
  => Hello

`PutsDebuggerer.print_engine`

(default = :ap)

Print engine is similar to printer, except it is focused on the scope of formatting the data object being printed (excluding metadata such as file name, line number, class name, method name, and expression, which are handled by the printer). As such, it is also a global method symbol or lambda expression. Examples of global methods are :p, :ap, and :pp. An example of a lambda expression is lambda {|object| puts object.to_a.join(" | ")}

Defaults to awesome_print. It does not load the library however until the first use of the pd command.

If you want to avoid loading awesome_print to use an alternative instead like amazing_print, make sure to load amazing_print and call PutsDebuggerer.print_engine = :ap before the first pd call (amazing_print works through ap just like awesome_print).

Example:

# File Name: /Users/User/example.rb
PutsDebuggerer.print_engine = :p
array = [1, [2, 3]]
pd array

Prints out:

[PD] /Users/User/example.rb:4 in Object.<main>
   > pd array
  => [1, [2, 3]]

`PutsDebuggerer.announcer`

(default = "[PD]") [shortcut: a]

Announcer (e.g. [PD]) to announce every print out with (default: "[PD]")

Example:

PutsDebuggerer.announcer = "*** PD ***\n  "
pd (x=1)

Prints out:

*** PD ***
   /Users/User/example.rb:2 in Object.<main>
   > pd x=1
  => "1"

`PutsDebuggerer.formatter`

(default = PutsDebuggerer::FORMATTER_DEFAULT)

Formatter used in every print out Passed a data argument with the following keys:

:announcer (String)
:caller (Array)
:class (String)
:file (String)
:footer (String)
:header (String)
:line_number (String)
:method (String)
:pd_expression (String)
:object (Object)
:object_printer (Proc)

NOTE: data for :object_printer is not a string, yet a proc that must be called to output value. It is a proc as it automatically handles usage of print_engine and encapsulates its details. In any case, data for :object is available should one want to avoid altogether.

Example:

PutsDebuggerer.formatter = -> (data) {
  puts "-<#{data[:announcer]}>-"
  puts "HEADER: #{data[:header]}"
  puts "FILE: #{data[:file]}"
  puts "LINE: #{data[:line_number]}"
  puts "CLASS: #{data[:class]}"
  puts "METHOD: #{data[:method]}"
  puts "EXPRESSION: #{data[:pd_expression]}"
  print "PRINT OUT: "
  data[:object_printer].call
  puts "CALLER: #{data[:caller].to_a.first}"
  puts "FOOTER: #{data[:footer]}"
}
pd (x=1)

Prints out:

-<[PD]>-
HEADER: ********************************************************************************
FILE: /Users/User/example.rb
LINE: 9
CLASS: Example
METHOD: test
EXPRESSION: x=1
PRINT OUT: 1
CALLER: #/Users/User/master_examples.rb:83:in `block (3 levels) in <top (required)>'
FOOTER: ********************************************************************************

`PutsDebuggerer.caller`

(default = nil) [shortcut: c]

Caller backtrace included at the end of every print out Passed an argument of true/false, nil, or depth as an integer.

true and -1 means include full caller backtrace
false and nil means do not include caller backtrace
depth (0-based) means include limited caller backtrace depth

Example:

# File Name: /Users/User/sample_app/lib/sample.rb
class Sample
  pd (x=1), caller: 3
end

Prints out (fictional):

[PD] /Users/User/sample_app/lib/sample.rb:3 in Sample.<class:Sample>
    > pd x=1, caller: 3
   => 1
     /Users/User/sample_app/lib/master_samples.rb:368:in \`block (3 levels) in <top (required)>\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/workspace.rb:87:in \`eval\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/workspace.rb:87:in \`evaluate\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/context.rb:381:in \`evaluate\'

Shortcut Example:

# File Name: /Users/User/sample_app/lib/sample.rb
class Sample
  pd (x=1), c: 3
end

Prints out (fictional):

[PD] /Users/User/sample_app/lib/sample.rb:3 in Sample.<class:Sample>
    > pd x=1, caller: 3
   => 1
     /Users/User/sample_app/lib/master_samples.rb:368:in \`block (3 levels) in <top (required)>\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/workspace.rb:87:in \`eval\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/workspace.rb:87:in \`evaluate\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/context.rb:381:in \`evaluate\'

Global Option Example:

# File Name: /Users/User/sample_app/lib/sample.rb
PutsDebuggerer.caller = 3 # always print 3 lines only of the stack trace
class Sample
  class << self
    def test
      pd (x=1)
      pd (x=2)
    end
  end
end
Sample.test

Prints out:

[PD] /Users/User/sample_app/lib/sample.rb:6 in Sample.test
    > pd (x=1)
   => 1
     /Users/User/sample_app/lib/master_samples.rb:368:in \`block (3 levels) in <top (required)>\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/workspace.rb:87:in \`eval\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/workspace.rb:87:in \`evaluate\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/context.rb:381:in \`evaluate\'
[PD] /Users/User/sample_app/lib/sample.rb:7 in Sample.test
    > pd (x=2)
   => 2
     /Users/User/sample_app/lib/master_samples.rb:368:in \`block (3 levels) in <top (required)>\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/workspace.rb:87:in \`eval\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/workspace.rb:87:in \`evaluate\'
     /Users/User/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/irb/context.rb:381:in \`evaluate\'

`PutsDebuggerer.run_at`

(default = nil)

Set condition for when to run as specified by an index, array, or range.

Default value is nil meaning always
Value as an Integer index (1-based) specifies at which run to print once
Value as an Array of indices specifies at which runs to print multiple times
Value as a range specifies at which runs to print multiple times, indefinitely if it ends with ..-1 or ...-1

Can be set globally via PutsDebuggerer.run_at or piecemeal via pd object, run_at: run_at_value

Global usage should be good enough for most cases. When there is a need to track a single expression among several, you may add the option piecemeal, but it expects the same exact object passed to pd for counting.

Examples (global):

  PutsDebuggerer.run_at = 1
  pd (x=1) # prints standard PD output
  pd (x=1) # prints nothing

  PutsDebuggerer.run_at = 2
  pd (x=1) # prints nothing
  pd (x=1) # prints standard PD output

  PutsDebuggerer.run_at = [1, 3]
  pd (x=1) # prints standard PD output
  pd (x=1) # prints nothing
  pd (x=1) # prints standard PD output
  pd (x=1) # prints nothing

  PutsDebuggerer.run_at = 3..5
  pd (x=1) # prints nothing
  pd (x=1) # prints nothing
  pd (x=1) # prints standard PD output
  pd (x=1) # prints standard PD output
  pd (x=1) # prints standard PD output
  pd (x=1) # prints nothing
  pd (x=1) # prints nothing

  PutsDebuggerer.run_at = 3...6
  pd (x=1) # prints nothing
  pd (x=1) # prints nothing
  pd (x=1) # prints standard PD output
  pd (x=1) # prints standard PD output
  pd (x=1) # prints standard PD output
  pd (x=1) # prints nothing

  PutsDebuggerer.run_at = 3..-1
  pd (x=1) # prints nothing
  pd (x=1) # prints nothing
  pd (x=1) # prints standard PD output
  pd (x=1) # ... continue printing indefinitely on all subsequent runs

  PutsDebuggerer.run_at = 3...-1
  pd (x=1) # prints nothing
  pd (x=1) # prints nothing
  pd (x=1) # prints standard PD output
  pd (x=1) # ... continue printing indefinitely on all subsequent runs

You may reset the run_at number counter via: PutsDebuggerer.reset_run_at_global_number for global usage.

And: PutsDebuggerer.reset_run_at_number or PutsDebuggerer.reset_run_at_numbers for piecemeal usage.

Bonus API

puts_debuggerer comes with the following bonus API methods:

`__caller_line_number__(caller_depth=0)`

Provides caller line number starting 1 level above caller of this method (with default caller_depth=0).

Example:

# File Name: lib/example.rb             # line 1
# Print out __caller_line_number__      # line 2
puts __caller_line_number__             # line 3

Prints out 3

`__caller_file__(caller_depth=0)`

Provides caller file starting 1 level above caller of this method (with default caller_depth=0).

Example:

# File Name: lib/example.rb
puts __caller_file__

Prints out lib/example.rb

`__caller_source_line__(caller_depth=0)`

Provides caller source line starting 1 level above caller of this method (with default caller_depth=0).

Example:

puts __caller_source_line__

Prints out puts __caller_source_line__

Compatibility

puts_debuggerer is fully compatible with:

Ruby
JRuby
IRB (including Rails Console)
Pry (experimental and fragile because Pry's API is not reliable)

Opal Ruby

puts_debuggerer provides partial-compatibility in Opal Ruby with everything working except:

AwesomePrint (using the :p printer instead)
Source code display

puts_debuggerer renders clickable source file/line links in Opal Ruby that take you to the source code in the web browser.

Here is an example of pd output in Opal:

[PD] http://localhost:3000/assets/views/garderie_rainbow_daily_agenda/app_view.self-72626d75e0f68a619b1c8ad139535d799d45ab6c730d083820b790d71338e983.js?body=1:72:12
   >
  => "body"

Note that it ignores the configured printer when printing exceptions as it relies on Opal's $stderr.puts instead to show the stack trace in the web console.

Change Log

CHANGELOG.md

TODO

TODO.md

Contributing

Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.
Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.
Fork the project.
Change directory into project
Run gem install bundler && bundle && rake and make sure RSpec tests are passing
Start a feature/bugfix branch.
Write RSpec tests, Code, Commit and push until you are happy with your contribution.
Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright

MIT

puts_debuggerer

Development

Runtime

Puts Debuggerer 1.0.1

Debugger-less Debugging FTW

Featured in State of the Art Rails 2023 Edition

Background

Instructions

Option 1: Bundler

Option 2: Manual

Awesome Print

Usage

`pd_inspect` kernel method

Ruby Logger and Logging::Logger

Options

`PutsDebuggerer.app_path`

`PutsDebuggerer.header`

`PutsDebuggerer.footer`

`PutsDebuggerer.wrapper`

`PutsDebuggerer.source_line_count`

`PutsDebuggerer.printer`

`PutsDebuggerer.print_engine`

`PutsDebuggerer.announcer`

`PutsDebuggerer.formatter`

`PutsDebuggerer.caller`

`PutsDebuggerer.run_at`

Bonus API

`__caller_line_number__(caller_depth=0)`

`__caller_file__(caller_depth=0)`

`__caller_source_line__(caller_depth=0)`

Compatibility

Opal Ruby

Change Log

TODO

Contributing

Copyright

puts_debuggerer

Development

Runtime

Puts Debuggerer 1.0.1

Debugger-less Debugging FTW

Featured in State of the Art Rails 2023 Edition

Background

Instructions

Option 1: Bundler

Option 2: Manual

Awesome Print

Usage

pd_inspect kernel method

Ruby Logger and Logging::Logger

Options

PutsDebuggerer.app_path

PutsDebuggerer.header

PutsDebuggerer.footer

PutsDebuggerer.wrapper

PutsDebuggerer.source_line_count

PutsDebuggerer.printer

PutsDebuggerer.print_engine

PutsDebuggerer.announcer

PutsDebuggerer.formatter

PutsDebuggerer.caller

PutsDebuggerer.run_at

Bonus API

__caller_line_number__(caller_depth=0)

__caller_file__(caller_depth=0)

__caller_source_line__(caller_depth=0)

Compatibility

Opal Ruby

Change Log

TODO

Contributing

Copyright

`pd_inspect` kernel method

`PutsDebuggerer.app_path`

`PutsDebuggerer.header`

`PutsDebuggerer.footer`

`PutsDebuggerer.wrapper`

`PutsDebuggerer.source_line_count`

`PutsDebuggerer.printer`

`PutsDebuggerer.print_engine`

`PutsDebuggerer.announcer`

`PutsDebuggerer.formatter`

`PutsDebuggerer.caller`

`PutsDebuggerer.run_at`

`__caller_line_number__(caller_depth=0)`

`__caller_file__(caller_depth=0)`

`__caller_source_line__(caller_depth=0)`