pry-byebug
Fast execution control in Pry
Adds step, next, finish and continue commands and breakpoints to Pry using byebug.
To use, invoke pry normally. No need to start your script or app differently.
Execution will stop in the first statement after your binding.pry
.
def some_method
puts 'Hello World' # Run 'step' in the console to move here
end
binding.pry
some_method # Execution will stop here.
puts 'Goodbye World' # Run 'next' in the console to move here.
Installation
Drop
gem 'pry-byebug'
in your Gemfile and run
bundle install
Make sure you include the gem globally or inside the :test
group if you plan
to use it to debug your tests!
Execution Commands
step: Step execution into the next line or method. Takes an optional numeric argument to step multiple times.
next: Step over to the next line within the same frame. Also takes an optional numeric argument to step multiple lines.
finish: Execute until current stack frame returns.
continue: Continue program execution and end the Pry session.
Matching Byebug Behaviour
If you're coming from Byebug or from Pry-Byebug versions previous to 3.0, you
may be lacking the 'n', 's', 'c' and 'f' aliases for the stepping commands.
These aliases were removed by default because they usually conflict with
scratch variable names. But it's very easy to reenable them if you still want
them, just add the following shortcuts to your ~/.pryrc
file:
if defined?(PryByebug)
Pry.commands.alias_command 'c', 'continue'
Pry.commands.alias_command 's', 'step'
Pry.commands.alias_command 'n', 'next'
Pry.commands.alias_command 'f', 'finish'
end
Also, you might find useful as well the repeat the last command by just hitting
the Enter
key (e.g., with step
or next
). To achieve that, add this to
your ~/.pryrc
file:
# Hit Enter to repeat last command
Pry::Commands.command /^$/, "repeat last command" do
_pry_.run_command Pry.history.to_a.last
end
Breakpoints
You can set and adjust breakpoints directly from a Pry session using the following commands:
break: Set a new breakpoint from a line number in the current file, a file and line number, or a method. Pass an optional expression to create a conditional breakpoint. Edit existing breakpoints via various flags.
Examples:
break SomeClass#run # Break at the start of `SomeClass#run`.
break Foo#bar if baz? # Break at `Foo#bar` only if `baz?`.
break app/models/user.rb:15 # Break at line 15 in user.rb.
break 14 # Break at line 14 in the current file.
break --condition 4 x > 2 # Change condition on breakpoint #4 to 'x > 2'.
break --condition 3 # Remove the condition on breakpoint #3.
break --delete 5 # Delete breakpoint #5.
break --disable-all # Disable all breakpoints.
break # List all breakpoints. (Same as `breakpoints`)
break --show 2 # Show details about breakpoint #2.
Type break --help
from a Pry session to see all available options.
breakpoints: List all defined breakpoints. Pass -v
or --verbose
to see
the source code around each breakpoint.
Caveats
Only supports MRI 2.0.0 or newer. For MRI 1.9.3 or older, use pry-debugger
Credits
- Gopal Patel (@nixme), creator of pry-debugger, and everybody who contributed to it. pry-byebug is a fork of pry-debugger so it wouldn't exist as it is without those contributions.
- John Mair (@banister), creator of pry.
Patches and bug reports are welcome.