(credit to Aaron Patterson for partial inspiration: https://tenderlovemaking.com/2016/02/05/i-am-a-puts-debuggerer.html)
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 methods and line numbers were invoked, 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, code statements, headers, footers, stack traces, and formats output nicely courtesy of awesome_print.
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
bug_or_band = 'beattle' # line 3
pd bug_or_band # line 4
Output:
[PD] /Users/User/trivia_app.rb:4
> pd bug_or_band # line 4
=> "beattle"
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 and line number 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
> 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
> 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
> 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
> 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
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
> 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
> 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
> pd order_details
=> "[Hard Cover] Pragmatic Ruby Book - English Version"
Wanna customize the header and add a footer too? No problem:
pd order_total, header: '>'*80
pd order_summary
pd order_details, footer: '<'*80
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
> 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
> 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
> 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
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
> 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
> 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
> 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
(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
> 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
> 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
> pd order_details
=> "[Hard Cover] Pragmatic Ruby Book - English Version"
There are many more options and powerful features in puts_debuggerer as detailed below.
Add the following to bundler's Gemfile
.
gem 'puts_debuggerer', '~> 0.12.0'
This is the recommended way for Rails apps. Optionally, you may create an initializer under config/initializers
named puts_debuggerer_options.rb
to enable further customizations as per the Options section below.
Or manually install and require library.
gem install puts_debuggerer -v0.12.0
require 'puts_debuggerer'
Or the shorter form (often helpful to quickly troubleshoot an app):
require 'pd'
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 won't require it either if it sees that you have a different print_engine
You may also avoid requiring in Bundler Gemfile
with require: false
:
gem "awesome_print", require: false
gem "puts_debuggerer"
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 as the default print engine for output).
Example:
# /Users/User/finance_calculator_app/pd_test.rb # line 1
bug = 'beattle' # 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
> pd "Show me the source of the bug: #{bug}"
=> "Show me the source of the bug: beattle"
[PD] /Users/User/finance_calculator_app/pd_test.rb:4
> pd "Show me the result of the calculation: #{(12.0/3.0)}"
=> "Show me the result of the calculation: 4.0"
In addition to the main object/expression output, you get to see the source file name, line number, and source code to help you debug and troubleshoot problems quicker (it even works in IRB and Pry).
Second, quickly locate printed lines using the Find feature (e.g. CTRL+F) by looking for:
- [PD]
- file:line_number
- 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
> greeting = "Hello #{pd(name)}"
=> "Hello Robert"
Happy puts_debuggerering!
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 (from logging gem) are supported as printers (learn more under PutsDebuggerer#printer).
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
> 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
> pd data, header: '>'*80, footer: '<'*80, announcer: " -<[PD]>-\n "
=> [1, [2, 3]]
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Details about all the available options are included below.
(default = nil
)
Sets absolute application path. Makes pd
file output relative to it.
If Rails was detected, it is automatically defaulted to Rails.root.to_s
# /Users/User/finance_calculator_app/pd_test.rb # line 1
PutsDebuggerer.app_path = File.join('/Users', 'User', 'finance_calculator_app') # line 2
bug = 'beattle' # line 3
pd "Show me the source of the bug: #{bug}" # line 4
Example Printout:
[PD] /pd_test.rb:4
> pd "Show me the source of the bug: #{bug}"
=> "Show me the source of the bug: beattle"
(default = '>'*80
)
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
> pd (x=1), header: true
=> "1"
Global Option Example:
PutsDebuggerer.header = true
pd (x=1)
pd (x=2)
Prints out:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[PD] /Users/User/example.rb:2
> pd (x=1)
=> "1"
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
[PD] /Users/User/example.rb:3
> pd (x=2)
=> "2"
(default = '<'*80
)
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
> pd (x=1), footer: true
=> "1"
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Global Option Example:
PutsDebuggerer.footer = true
pd (x=1)
pd (x=2)
Prints out:
[PD] /Users/User/example.rb:2
> pd (x=1)
=> "1"
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
[PD] /Users/User/example.rb:3
> pd (x=2)
=> "2"
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
(default = '*'*80
)
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
> pd x=1, wrapper: true
=> "1"
********************************************************************************
Global Option Example:
PutsDebuggerer.wrapper = true
pd (x=1)
pd (x=2)
Prints out:
********************************************************************************
[PD] /Users/User/example.rb:2
> pd (x=1)
=> "1"
********************************************************************************
********************************************************************************
[PD] /Users/User/example.rb:3
> pd (x=2)
=> "2"
********************************************************************************
(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
> 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
> pd (true ||
false), source_line_count: 2
=> "true"
(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:
# File Name: /Users/User/example.rb
PutsDebuggerer.printer = lambda {|output| Rails.logger.error(output)}
str = "Hello"
pd str
Prints out in the Rails app log as error lines:
[PD] /Users/User/example.rb:5
> pd str
=> Hello
(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,
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.
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
> pd array
=> [1, [2, 3]]
(default = "[PD]"
)
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
> pd x=1
=> "1"
(default = PutsDebuggerer::FORMATTER_DEFAULT
)
Formatter used in every print out Passed a data argument with the following keys:
- :announcer (string)
- :caller (array)
- :file (string)
- :footer (string)
- :header (string)
- :line_number (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 "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]>-
FILE: /Users/User/example.rb
HEADER: ********************************************************************************
LINE: 9
EXPRESSION: x=1
PRINT OUT: 1
CALLER: #/Users/User/master_examples.rb:83:in `block (3 levels) in <top (required)>'
FOOTER: ********************************************************************************
(default = nil)
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
PutsDebuggerer.caller = 3
pd (x=1)
Prints out:
[PD] /Users/User/sample_app/lib/sample.rb:3
> 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\'
Global Option Example:
# File Name: /Users/User/sample_app/lib/sample.rb
PutsDebuggerer.caller = 3 # always print 3 lines only of the stack trace
pd (x=1)
pd (x=2)
Prints out:
[PD] /Users/User/sample_app/lib/sample.rb:2
> 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:3
> 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\'
(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.
puts_debuggerer comes with the following bonus API methods:
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
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
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__
puts_debuggerer is fully compatible with:
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.
- 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 (c) 2017-2020 - Andy Maleh.