I have been having an issue lately. When trying to debug anything I run my file and use Byebug. However when I run any command on Byebug my main menu command line of terminal appears. Ex:
*****$: ruby file.rb
require "byebug"
debugger
1: def array(array_1, array_2)
if array_1 == array_2
true
else
false
end
end
(byebug) c
*****$:
Related
I am trying to pause an rspec test using binding.pry to understand why it fails. Here is a simplified version:
def copy_db
binding.pry
puts 'hello world'
end
The binding.pry pauses execution but any input in the session causes it to end. Any ideas why this would be? This is not a rails project.
I'm not sure if the previous answer was sufficient, but another thing you could try besides binding.pry is using the byebug gem.
In your Gemfile add:
gem "byebug"
In the terminal (at the root of the project directory) run:
$ bundle install
Require 'byebug' at the top of your code and insert a 'debugger' wherever you want to set a breakpoint:
require 'byebug'
def copy_db
debugger
puts 'hello world'
end
And it will pause rspec and enter the byebug debugger, which lets you display the values of various variables as you step through each line.
[1, 4] in path/to/your/file.rb
1: def copy_db
2: debugger
=> 3: puts 'hello world'
4: end
(byebug)_
When I'm using pry, the history of pry keeps overwriting my irb history and it is very annoying. If i'm using pry, i'd like to see pry history and if i'm using irb, i'd like to see irb history. Is there an obvious problem in my configuration?
~/.irbrc looks like
IRB.conf[:AUTO_INDENT] = true
IRB.conf[:USE_READLINE] = true
IRB.conf[:LOAD_MODULES] = [] unless IRB.conf.key?(:LOAD_MODULES)
unless IRB.conf[:LOAD_MODULES].include?('irb/completion')
IRB.conf[:LOAD_MODULES] << 'irb/completion'
end
IRB.conf[:SAVE_HISTORY] = 1000
my .pryrc file is empty, which based on docs indicates to me that pry should be using .pry_history, which appears to be happening.
/etc/irbrc looks like
# Some default enhancements/settings for IRB, based on
# http://wiki.rubygarden.org/Ruby/page/show/Irb/TipsAndTricks
unless defined? ETC_IRBRC_LOADED
# Require RubyGems by default.
require 'rubygems'
# Activate auto-completion.
require 'irb/completion'
# Use the simple prompt if possible.
IRB.conf[:PROMPT_MODE] = :SIMPLE if IRB.conf[:PROMPT_MODE] == :DEFAULT
# Setup permanent history.
HISTFILE = "~/.irb_history"
MAXHISTSIZE = 100
begin
histfile = File::expand_path(HISTFILE)
if File::exists?(histfile)
lines = IO::readlines(histfile).collect { |line| line.chomp }
puts "Read #{lines.nitems} saved history commands from '#{histfile}'." if $VERBOSE
Readline::HISTORY.push(*lines)
else
puts "History file '#{histfile}' was empty or non-existant." if $VERBOSE
end
Kernel::at_exit do
lines = Readline::HISTORY.to_a.reverse.uniq.reverse
lines = lines[-MAXHISTSIZE, MAXHISTSIZE] if lines.nitems > MAXHISTSIZE
puts "Saving #{lines.length} history lines to '#{histfile}'." if $VERBOSE
File::open(histfile, File::WRONLY|File::CREAT|File::TRUNC) { |io| io.puts lines.join("\n") }
end
rescue => e
puts "Error when configuring permanent history: #{e}" if $VERBOSE
end
ETC_IRBRC_LOADED=true
end
Why the problem happens
Both Pry and IRB write their histories to Readline::HISTORY. When you enter Pry from IRB (or rails console) you have all your IRB history already in Readline::HISTORY. Pry then loads its history on top of that. When you exit Pry Readline::HISTORY isn't changed so you end up back in IRB with all of Pry's history appending to IRB's history. Finally, when you exit IRB it writes the history including Pry's to IRB's history file thus clobbering it.
Current state of the issue
I did some searching and found this is a known issue with Pry. I was also really interested in the problem so I managed to work up a solution that is awaiting a pull request review.
Workaround until merged
If you'd like to try it out before it get's merged you can grab the version from the branch I made on my fork of Pry. You can find it at https://github.com/agrberg/pry under branch save_irb_history_and_replace_on_close. If you use bundler all you need to do is add or update your line for pry to:
gem 'pry', git: 'git#github.com:agrberg/pry.git', branch: 'save_irb_history_and_replace_on_close'
I'm new to programming. Just about to start learning Ruby. I already took a console class, but I am stuck here.
I'm using a mac 10.6.8. I have done a quick 1+2 in the sublime text editor. I saved it. I went over to my console typed irb and then typed ruby example.rb. I have read elsewhere here that typing require './example' would help....it didn't. I am getting the following
NameError: undefined local variable or method `example' for main:Object
from (irb):2
from /usr/local/rvm/rubies/ruby-1.9.3-p392/bin/irb:16:in `<main>'
I don't understand what I am doing wrong. Thank you for your help. I really appreciate it.
-L
I would do as below:
kirti#kirti-Aspire-5733Z:~$ irb
2.0.0p0 :001 > require 'fileutils'
=> true
2.0.0p0 :002 > FileUtils.pwd
=> "/home/kirti"
2.0.0p0 :003 > FileUtils.cd "/home/kirti/ruby"
=> nil
2.0.0p0 :004 > load "./SO.rb"
3
=> true
2.0.0p0 :005 > require "./SO.rb"
3
=> true
My SO.rb file contains the below line :
puts 1+2
May be you wanna give a try.
Step 1: Navigate to your project/file folder by using command "cd folder_name/folder_location"
Step 2: load './example.rb'
For better solution you may wanna define some function inside example.rb
Like:
def sum
1 + 2
end
And to get the output enter sum in irb after loading the example.rb file.
irb is the interactive ruby shell. Within the shell, everything you type is interpreted as Ruby code, not bash commands. So, for example:
bash> puts 1 + 2
# command not found: puts
# this happens because you're not in a Ruby shell
bash> irb
# now you're in a Ruby shell
irb> puts 1 + 2
# 3
If you wrote some code in example.rb, you have two options:
From the bash shell, run ruby example.rb (from the same directory where your example.rb file is saved.
From the irb console, you can require 'example', which will load the contents of example.rb into your interpreter. In this case, it will immediately execute the Ruby code. If you wrapped the contents of example.rb in a class, it would load the class, but not execute code within it until you instantiated/called it.
Hopefully that helps!
My guess is that you are typing (into irb):
require example.rb
When you need to type:
require './example.rb'
The first tells ruby: "require what is in a variable called example". Because you did not define a variable called example, it results in the no variable or method error.
The second tells ruby: "require a string './example.rb'". Since the require method essentially knows how to find the file name passed as a string and evaluate the file, you'll get the right output
By the way, for this example, example.rb needs to be in the same directory. If example.rb is in another directory, you'll need to use the full path (I won't expand on it here) to source it.
You'll also notice that the output will look something like this:
3
=> true
This is because the file was evaluated (executing the code: puts 1+2) and the require method returns true to indicate it evaluated the file.
If you require the file again, you'll get false because the file is already loaded.
Currently, I'm running all selenium scripts in my test suite (written by Selenium Ruby Webdriver) at one time by using rake gem in "Start Command Prompt with Ruby" terminal.
To do this I have to create a file with name "rakefile.rb" with below content and just call "rake" in my terminal: (I have known this knowledge based on the guide of a person in my previous post how to export results when running selenium ruby webdriver scripts to output files from command prompt ruby window).
task :default do
$stdout = File.new('console.out', 'w')
$stdout.sync = true
FileList['test*.rb'].each { |file|
begin
ruby file
rescue
puts "The following tests reported unexpected behavior:"
puts "#{file} \n"
end
}
end
However, I do not know how to modify "rakefile.rb" to be able to export the content of executing each failed tests (that being displayed on my Terminal) to each output file ? It means that I expect the content of executing each my script will be written to output files instead of displaying on my Ruby terminal (ex: when I'm running the test script "test_GI-1.rb", then the content of executing this script will be written to an output file "test_GI-1.rb.out" instead of showing in my Terminal.
I modified my "rakefile.rb" to something like ruby file >> test.rb.out, but it does not work at all (this thing only works when I type directly the thing like ruby test.rb >> output.out on my Ruby Terminal). Anybody please guide me a way. Thanks so much.
I have not tried this out, but I guess this should work
task :default do
FileList['test*.rb'].each { |file|
begin
system("ruby #{file} > #{file}.log")
rescue
puts "The following tests reported unexpected behavior:"
puts "#{file} \n"
end
}
end
Based on new requirements -
UPDATE
task :default do
logfile.new("console.out", "w")
FileList['test*.rb'].each { |file|
begin
system("ruby #{file} > #{file}.log")
rescue
logfile.puts("The following tests reported unexpected behavior:")
logfile.puts("#{file} \n")
end
}
end
Can I drop to an IRB prompt from a running Ruby script?
I want to run a script, but then have it give me an IRB prompt at a point in the program with the current state of the program, but not just by running rdebug and having a breakpoint.
Pry (an IRB alternative) also lets you do this, in fact it was designed from the ground up for exactly this use case :)
It's as easy as putting binding.pry at the point you want to start the session:
require 'pry'
x = 10
binding.pry
And inside the session:
pry(main)> puts x
=> 10
Check out the website: http://pry.github.com
Pry let's you:
drop into a session at any point in your code
view method source code
view method documentation (not using RI so you dont have to pre-generate it)
pop in and out of different contexts
syntax highlighting
gist integration
view and replay history
open editors to edit methods using edit obj.my_method syntax
A tonne more great and original features
you can use ruby-debug to get access to irb
require 'rubygems'
require 'ruby-debug'
x = 23
puts "welcome"
debugger
puts "end"
when program reaches debugger you will get access to irb.
apparently it requires a chunk of code to drop into irb.
Here's the link (seems to work well).
http://jameskilton.com/2009/04/02/embedding-irb-into-your-ruby-application
require 'irb'
module IRB
def self.start_session(binding) # call this method to drop into irb
unless #__initialized
args = ARGV
ARGV.replace(ARGV.dup)
IRB.setup(nil)
ARGV.replace(args)
#__initialized = true
end
workspace = WorkSpace.new(binding)
irb = Irb.new(workspace)
#CONF[:IRB_RC].call(irb.context) if #CONF[:IRB_RC]
#CONF[:MAIN_CONTEXT] = irb.context
catch(:IRB_EXIT) do
irb.eval_input
end
end
end
This feature is available from Ruby 2.4. You can just use binding.irb
E.g.
require 'irb'
a = 10
binding.irb
puts a
If you run above code, you will get irb console, so that you can inspect values of local variables and anything else that is in scope.
Source: http://blog.redpanthers.co/new-binding-irb-introduced-ruby-2-4/
Ruby commit: https://github.com/ruby/ruby/commit/493e48897421d176a8faf0f0820323d79ecdf94a
Just add this line to where you want the breakpoint:
require 'ruby-debug';debugger
but i suggest use pry instead of irb, which is super handy, insert the following line instead:
require 'pry'; binding.pry
I'm quite late to the game but if you're loading a script from within irb/pry already, a simple raise also works to pop you back out to the irb/pry prompt. I use this quite often when writing one off scripts within the rails console.