##はじめに
本日はデバッガに関してまとめていきます。
というのも、私はdebuggerを利用していたのですが、binding.pryというデバッガの存在を知り、
双方がどのように異なるのか？理解出来ていなかったからです・・・
##結論
先に結論から申しますと、
ほぼ同じものだということです！
debuggerの後継にあたるものがbinding.pryだそうです。
とは言っても、導入の仕方や機能も多少異なりますので以下にまとめたいと思います。
##デバッガとは？
因みにですが、デバッガとは以下のことを示します。
デバッガとは、デバッグを支援するプログラムのこと。対話的に利用者がプログラムを動作させたり、プログラムが使っている変数等を表示させる機能がある。近年では統合開発環境に含まれていることが多い。
因みに僕は、viewやテストが通らない際に、変数に何が与えられているのか確認するために使用することが多いです！
##導入の仕方
debuggerを使用するためには
$ gem install byebug
binding.pryを実行するためには
$ gem install pry-byebug
というようにそれぞれのgemをinstallする必要があります。
##使用できる機能
dubugger
(byebug) help
break -- Sets breakpoints in the source code
catch -- Handles exception catchpoints
condition -- Sets conditions on breakpoints
continue -- Runs until program ends, hits a breakpoint or reaches aline
debug -- Spawns a subdebugger
delete -- Deletes breakpoints
disable -- Disables breakpoints or displays
display -- Evaluates expressions every time the debugger stops
down -- Moves to a lower frame in the stack trace
edit -- Edits source files
enable -- Enables breakpoints or displays
finish -- Runs the program until frame returns
frame -- Moves to a frame in the call stack
help -- Helps you using byebug
history -- Shows byebug's history of commands
info -- Shows several informations about the program being debugged
interrupt -- Interrupts the program
irb -- Starts an IRB session
kill -- Sends a signal to the current process
list -- Lists lines of source code
method -- Shows methods of an object, class or module
next -- Runs one or more lines of code
pry -- Starts a Pry session
quit -- Exits byebug
restart -- Restarts the debugged program
save -- Saves current byebug session to a file
set -- Modifies byebug settings
show -- Shows byebug settings
source -- Restores a previously saved byebug session
step -- Steps into blocks or methods one or more times
thread -- Commands to manipulate threads
tracevar -- Enables tracing of a global variable
undisplay -- Stops displaying all or some expressions when program stops
untracevar -- Stops tracing a global variable
up -- Moves to a higher frame in the stack trace
var -- Shows variables and its values
where -- Displays the backtrace
binding.pry
[1] pry(#<RSpec::ExampleGroups::Products>)> help
Help
help Show a list of commands or information about a specific command.
Context
cd Move into a new context (object or scope).
find-method Recursively search for a method within a class/module or the current namespace.
ls Show the list of vars and methods in the current scope.
pry-backtrace Show the backtrace for the pry session.
raise-up Raise an exception out of the current pry instance.
reset Reset the repl to a clean state.
watch Watch the value of an expression and print a notification whenever it changes.
whereami Show code surrounding the current context.
wtf? Show the backtrace of the most recent exception.
Editing
/^\s*!\s*$/ Clear the input buffer.
amend-line Amend a line of input in multi-line mode.
edit Invoke the default editor on a file.
hist Show and replay readline history.
play Playback a string variable, method, line, or file as input.
show-input Show the contents of the input buffer for the current multi-line expression.
Introspection
ri View ri documentation.
show-doc Show the documentation for a method or class.
stat View method information and set _file_ and _dir_ locals.
Gems
gem-cd Change working directory to specified gem's directory.
gem-install Install a gem and refresh the gem cache.
gem-list List and search installed gems.
gem-open Opens the working directory of the gem in your editor.
gem-readme Show the readme bundled with a rubygem
gem-search Search for a gem with the rubygems.org json api
Commands
import-set Import a pry command set.
install-command Install a disabled command.
Aliases
!!! Alias for `exit-program`
!!@ Alias for `exit-all`
$ Alias for `show-source`
(?-mix:whereami[!?]+) Alias for `whereami`
? Alias for `show-doc`
@ Alias for `whereami`
clipit Alias for `gist --clip`
file-mode Alias for `shell-mode`
find-routes Alias for `find-route`
history Alias for `hist`
quit Alias for `exit`
quit-program Alias for `exit-program`
reload-method Alias for `reload-code`
show-method Alias for `show-source`
Byebug
backtrace Display the current stack.
break Set or edit a breakpoint.
continue Continue program execution and end the pry session.
down Move current frame down.
finish Execute until current stack frame returns.
frame Move to specified frame #.
next Execute the next line within the current stack frame.
step Step execution into the next line or method.
up Move current frame up.
Input and output
.<shell command> All text following a '.' is forwarded to the shell.
cat Show code from a file, pry's input buffer, or the last exception.
change-inspector Change the current inspector proc.
change-prompt Change the current prompt.
fix-indent Correct the indentation for contents of the input buffer
list-inspectors List the inspector procs available for use.
list-prompts List the prompts available for use.
save-file Export to a file using content from the repl.
shell-mode Toggle shell mode. bring in pwd prompt and file completion.
Misc
gist Upload code, docs, history to https://gist.github.com/.
pry-version Show pry version.
reload-code Reload the source file that contains the specifiedcode object.
toggle-color Toggle syntax highlighting.
Navigating pry
!pry Start a pry session on current self.
disable-pry Stops all future calls to pry and exits the current session.
exit Pop the previous binding.
exit-program End the current program.
jump-to Jump to a binding further up the stack.
nesting Show nesting information.
switch-to Start a new subsession on a binding in the currentstack.
Rails
find-route See which urls match a given controller.
recognize-path See which route matches a url.
show-middleware Show all middleware (that rails knows about).
show-model Show the given model.
show-models Show all models.
show-routes Show all routes in match order.
Prompts
simple-prompt Toggle the simple prompt.
Pry-byebug (v3.6.0)
exit-all End the current pry session.
Pry-doc (v0.13.4)
show-source Show the source for a method or class.
ふむふむ。
実際に使用できる機能はbinding.pryの方が多いようですし、コマンドも微妙に異なりますね。
たとえばbinding.pryを実行した際ではrestartコマンドが使えなかったりします。
##最後に
どちらかを使わないといけないなど決まりはありませんが、
調べてみたところbinding.pryの方が新しいこともあり、ネット上に情報が多いですね。
どちらを使用するか迷っている人は、binding.pryの方がオススメかもしれません。