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pry--pry/lib/pry/command.rb
2014-03-25 16:13:05 +01:00

692 lines
21 KiB
Ruby

require 'delegate'
require 'pry/helpers/documentation_helpers'
class Pry
# The super-class of all commands, new commands should be created by calling
# {Pry::CommandSet#command} which creates a BlockCommand or {Pry::CommandSet#create_command}
# which creates a ClassCommand. Please don't use this class directly.
class Command
extend Helpers::DocumentationHelpers
extend CodeObject::Helpers
# represents a void return value for a command
VOID_VALUE = Object.new
# give it a nice inspect
def VOID_VALUE.inspect() "void" end
# Properties of the command itself (as passed as arguments to
# {CommandSet#command} or {CommandSet#create_command}).
class << self
attr_writer :block
attr_writer :description
attr_writer :command_options
attr_writer :match
def match(arg=nil)
if arg
@command_options ||= default_options(arg)
@command_options[:listing] = arg.is_a?(String) ? arg : arg.inspect
@match = arg
end
@match ||= nil
end
# Define or get the command's description
def description(arg=nil)
@description = arg if arg
@description ||= nil
end
# Define or get the command's options
def command_options(arg=nil)
@command_options ||= default_options(match)
@command_options.merge!(arg) if arg
@command_options
end
# backward compatibility
alias_method :options, :command_options
alias_method :options=, :command_options=
# Define or get the command's banner
def banner(arg=nil)
@banner = arg if arg
@banner || description
end
def block
@block || instance_method(:process)
end
def source
file, line = block.source_location
strip_leading_whitespace(Pry::Code.from_file(file).expression_at(line))
end
def doc
new.help
end
def source_location
block.source_location
end
def source_file
Array(block.source_location).first
end
alias_method :file, :source_file
def source_line
Array(block.source_location).last
end
alias_method :line, :source_line
def default_options(match)
{
:requires_gem => [],
:keep_retval => false,
:argument_required => false,
:interpolate => true,
:shellwords => true,
:listing => (String === match ? match : match.inspect),
:use_prefix => true,
:takes_block => false
}
end
end
# Make those properties accessible to instances
def name; self.class.name; end
def match; self.class.match; end
def description; self.class.description; end
def block; self.class.block; end
def command_options; self.class.options; end
def command_name; self.class.command_name; end
def source; self.class.source; end
def source_location; self.class.source_location; end
class << self
def name
super.to_s == "" ? "#<class(Pry::Command #{match.inspect})>" : super
end
def inspect
name
end
def command_name
self.options[:listing]
end
# Create a new command with the given properties.
# @param [String, Regex] match The thing that triggers this command
# @param [String] description The description to appear in `help`
# @param [Hash] options Behavioral options (see {Pry::CommandSet#command})
# @param [Module] helpers A module of helper functions to be included.
# @yield optional, used for BlockCommands
# @return [Class] (a subclass of {Pry::Command})
def subclass(match, description, options, helpers, &block)
klass = Class.new(self)
klass.send(:include, helpers)
klass.match = match
klass.description = description
klass.command_options = options
klass.block = block
klass
end
# Should this command be called for the given line?
# @param [String] val A line input at the REPL
# @return [Boolean]
def matches?(val)
command_regex =~ val
end
# How well does this command match the given line?
#
# Higher scores are better because they imply that this command matches
# the line more closely.
#
# The score is calculated by taking the number of characters at the start
# of the string that are used only to identify the command, not as part of
# the arguments.
#
# @example
# /\.(.*)/.match_score(".foo") #=> 1
# /\.*(.*)/.match_score("...foo") #=> 3
# 'hi'.match_score("hi there") #=> 2
#
# @param [String] val A line input at the REPL
# @return [Fixnum]
def match_score(val)
if command_regex =~ val
Regexp.last_match.size > 1 ? Regexp.last_match.begin(1) : Regexp.last_match.end(0)
else
-1
end
end
# Store hooks to be run before or after the command body.
# @see {Pry::CommandSet#before_command}
# @see {Pry::CommandSet#after_command}
def hooks
@hooks ||= {:before => [], :after => []}
end
def command_regex
pr = Pry.respond_to?(:config) ? Pry.config.command_prefix : ""
prefix = convert_to_regex(pr)
prefix = "(?:#{prefix})?" unless options[:use_prefix]
/^#{prefix}#{convert_to_regex(match)}(?!\S)/
end
def convert_to_regex(obj)
case obj
when String
Regexp.escape(obj)
else
obj
end
end
# The group in which the command should be displayed in "help" output.
# This is usually auto-generated from directory naming, but it can be
# manually overridden if necessary.
# Group should not be changed once it is initialized.
def group(name=nil)
@group ||= if name
name
else
case Pry::Method(block).source_file
when %r{/pry/.*_commands/(.*).rb}
$1.capitalize.gsub(/_/, " ")
when %r{(pry-\w+)-([\d\.]+([\w\.]+)?)}
name, version = $1, $2
"#{name.to_s} (v#{version.to_s})"
when /pryrc/
"~/.pryrc"
else
"(other)"
end
end
end
end
# Properties of one execution of a command (passed by {Pry#run_command} as a hash of
# context and expanded in `#initialize`
attr_accessor :output
attr_accessor :target
attr_accessor :captures
attr_accessor :eval_string
attr_accessor :arg_string
attr_accessor :context
attr_accessor :command_set
attr_accessor :_pry_
# The block we pass *into* a command so long as `:takes_block` is
# not equal to `false`
# @example
# my-command | do
# puts "block content"
# end
attr_accessor :command_block
# Run a command from another command.
# @param [String] command_string The string that invokes the command
# @param [Array] args Further arguments to pass to the command
# @example
# run "show-input"
# @example
# run ".ls"
# @example
# run "amend-line", "5", 'puts "hello world"'
def run(command_string, *args)
command_string = _pry_.config.command_prefix.to_s + command_string
complete_string = "#{command_string} #{args.join(" ")}".rstrip
command_set.process_line(complete_string, context)
end
def commands
command_set.to_hash
end
def text
Pry::Helpers::Text
end
def void
VOID_VALUE
end
include Pry::Helpers::BaseHelpers
include Pry::Helpers::CommandHelpers
# Instantiate a command, in preparation for calling it.
# @param [Hash] context The runtime context to use with this command.
def initialize(context={})
self.context = context
self.target = context[:target]
self.output = context[:output]
self.eval_string = context[:eval_string]
self.command_set = context[:command_set]
self._pry_ = context[:pry_instance]
end
# @return [Object] The value of `self` inside the `target` binding.
def target_self; target.eval('self'); end
# @return [Hash] Pry commands can store arbitrary state
# here. This state persists between subsequent command invocations.
# All state saved here is unique to the command, it does not
# need to be namespaced.
# @example
# state.my_state = "my state" # this will not conflict with any
# # `state.my_state` used in another command.
def state
_pry_.command_state[match] ||= Pry::Config.from_hash({})
end
# Revaluate the string (str) and perform interpolation.
# @param [String] str The string to reevaluate with interpolation.
#
# @return [String] The reevaluated string with interpolations
# applied (if any).
def interpolate_string(str)
dumped_str = str.dump
if dumped_str.gsub!(/\\\#\{/, '#{')
target.eval(dumped_str)
else
str
end
end
# Display a warning if a command collides with a local/method in
# the current scope.
def check_for_command_collision(command_match, arg_string)
collision_type = target.eval("defined?(#{command_match})")
collision_type ||= 'local-variable' if arg_string.match(%r{\A\s*[-+*/%&|^]*=})
if collision_type
output.puts "#{text.bold('WARNING:')} Calling Pry command '#{command_match}', which conflicts with a #{collision_type}.\n\n"
end
rescue Pry::RescuableException
end
# Extract necessary information from a line that Command.matches? this
# command.
#
# Returns an array of four elements:
#
# ```
# [String] the portion of the line that matched with the Command match
# [String] a string of all the arguments (i.e. everything but the match)
# [Array] the captures caught by the command_regex
# [Array] the arguments obtained by splitting the arg_string
# ```
#
# @param [String] val The line of input
# @return [Array]
def tokenize(val)
val.replace(interpolate_string(val)) if command_options[:interpolate]
self.class.command_regex =~ val
# please call Command.matches? before Command#call_safely
raise CommandError, "fatal: called a command which didn't match?!" unless Regexp.last_match
captures = Regexp.last_match.captures
pos = Regexp.last_match.end(0)
arg_string = val[pos..-1]
# remove the one leading space if it exists
arg_string.slice!(0) if arg_string.start_with?(" ")
# process and pass a block if one is found
pass_block(arg_string) if command_options[:takes_block]
if arg_string
args = command_options[:shellwords] ? Shellwords.shellwords(arg_string) : arg_string.split(" ")
else
args = []
end
[val[0..pos].rstrip, arg_string, captures, args]
end
# Process a line that Command.matches? this command.
# @param [String] line The line to process
# @return [Object, Command::VOID_VALUE]
def process_line(line)
command_match, arg_string, captures, args = tokenize(line)
check_for_command_collision(command_match, arg_string) if Pry.config.collision_warning
self.arg_string = arg_string
self.captures = captures
call_safely(*(captures + args))
end
# Pass a block argument to a command.
# @param [String] arg_string The arguments (as a string) passed to the command.
# We inspect these for a '| do' or a '| {' and if we find it we use it
# to start a block input sequence. Once we have a complete
# block, we save it to an accessor that can be retrieved from the command context.
# Note that if we find the '| do' or '| {' we delete this and the
# elements following it from `arg_string`.
def pass_block(arg_string)
# Workaround for weird JRuby bug where rindex in this case can return nil
# even when there's a match.
arg_string.scan(/\| *(?:do|\{)/)
block_index = $~ && $~.offset(0)[0]
return if !block_index
block_init_string = arg_string.slice!(block_index..-1)[1..-1]
prime_string = "proc #{block_init_string}\n"
if !Pry::Code.complete_expression?(prime_string)
block_string = _pry_.r(target, prime_string)
else
block_string = prime_string
end
begin
self.command_block = target.eval(block_string)
rescue Pry::RescuableException
raise CommandError, "Incomplete block definition."
end
end
private :pass_block
# Run the command with the given `args`.
#
# This is a public wrapper around `#call` which ensures all preconditions
# are met.
#
# @param [Array<String>] args The arguments to pass to this command.
# @return [Object] The return value of the `#call` method, or
# {Command::VOID_VALUE}.
def call_safely(*args)
unless dependencies_met?
gems_needed = Array(command_options[:requires_gem])
gems_not_installed = gems_needed.select { |g| !Rubygem.installed?(g) }
output.puts "\nThe command '#{command_name}' is #{text.bold("unavailable")} because it requires the following gems to be installed: #{(gems_not_installed.join(", "))}"
output.puts "-"
output.puts "Type `install-command #{command_name}` to install the required gems and activate this command."
return void
end
if command_options[:argument_required] && args.empty?
raise CommandError, "The command '#{command_name}' requires an argument."
end
ret = call_with_hooks(*args)
command_options[:keep_retval] ? ret : void
end
# Are all the gems required to use this command installed?
#
# @return Boolean
def dependencies_met?
@dependencies_met ||= command_dependencies_met?(command_options)
end
# Generate completions for this command
#
# @param [String] search The line typed so far
# @return [Array<String>] Completion words
def complete(search)
[]
end
private
# Run the `#call` method and all the registered hooks.
# @param [Array<String>] args The arguments to `#call`
# @return [Object] The return value from `#call`
def call_with_hooks(*args)
self.class.hooks[:before].each do |block|
instance_exec(*args, &block)
end
ret = call(*args)
self.class.hooks[:after].each do |block|
ret = instance_exec(*args, &block)
end
ret
end
# Fix the number of arguments we pass to a block to avoid arity warnings.
# @param [Fixnum] arity The arity of the block
# @param [Array] args The arguments to pass
# @return [Array] A (possibly shorter) array of the arguments to pass
def correct_arg_arity(arity, args)
case
when arity < 0
args
when arity == 0
[]
when arity > 0
args.values_at(*(0..(arity - 1)).to_a)
end
end
end
# A super-class for Commands that are created with a single block.
#
# This class ensures that the block is called with the correct number of arguments
# and the right context.
#
# Create subclasses using {Pry::CommandSet#command}.
class BlockCommand < Command
# backwards compatibility
alias_method :opts, :context
# Call the block that was registered with this command.
# @param [Array<String>] args The arguments passed
# @return [Object] The return value of the block
def call(*args)
instance_exec(*correct_arg_arity(block.arity, args), &block)
end
def help
"#{command_options[:listing].to_s.ljust(18)} #{description}"
end
end
# A super-class of Commands with structure.
#
# This class implements the bare-minimum functionality that a command should
# have, namely a --help switch, and then delegates actual processing to its
# subclasses.
#
# Create subclasses using {Pry::CommandSet#create_command}, and override the
# `options(opt)` method to set up an instance of Slop, and the `process`
# method to actually run the command. If necessary, you can also override
# `setup` which will be called before `options`, for example to require any
# gems your command needs to run, or to set up state.
class ClassCommand < Command
class << self
# Ensure that subclasses inherit the options, description and
# match from a ClassCommand super class.
def inherited(klass)
klass.match match
klass.description description
klass.command_options options
end
def source
source_object.source
end
def doc
new.help
end
def source_location
source_object.source_location
end
def source_file
source_object.source_file
end
alias_method :file, :source_file
def source_line
source_object.source_line
end
alias_method :line, :source_line
private
# The object used to extract the source for the command.
#
# This should be a `Pry::Method(block)` for a command made with `create_command`
# and a `Pry::WrappedModule(self)` for a command that's a standard class.
# @return [Pry::WrappedModule, Pry::Method]
def source_object
@source_object ||= if name =~ /^[A-Z]/
Pry::WrappedModule(self)
else
Pry::Method(block)
end
end
end
attr_accessor :opts
attr_accessor :args
# Set up `opts` and `args`, and then call `process`.
#
# This method will display help if necessary.
#
# @param [Array<String>] args The arguments passed
# @return [Object] The return value of `process` or VOID_VALUE
def call(*args)
setup
self.opts = slop
self.args = self.opts.parse!(args)
if opts.present?(:help)
output.puts slop.help
void
else
process(*correct_arg_arity(method(:process).arity, args))
end
end
# Return the help generated by Slop for this command.
def help
slop.help
end
# Return an instance of Slop that can parse either subcommands or the
# options that this command accepts.
def slop
Slop.new do |opt|
opt.banner(unindent(self.class.banner))
subcommands(opt)
options(opt)
opt.on :h, :help, 'Show this message.'
end
end
# Generate shell completions
# @param [String] search The line typed so far
# @return [Array<String>] the words to complete
def complete(search)
slop.map do |opt|
[opt.long && "--#{opt.long} " || opt.short && "-#{opt.short}"]
end.flatten(1).compact + super
end
# A method called just before `options(opt)` as part of `call`.
#
# This method can be used to set up any context your command needs to run,
# for example requiring gems, or setting default values for options.
#
# @example
# def setup
# require 'gist'
# @action = :method
# end
def setup; end
# A method to setup Slop commands so it can parse the subcommands your
# command expects. If you need to set up default values, use `setup`
# instead.
#
# @example A minimal example
# def subcommands(cmd)
# cmd.command :download do |opt|
# description 'Downloads a content from a server'
#
# opt.on :verbose, 'Use verbose output'
#
# run do |options, arguments|
# ContentDownloader.download(options, arguments)
# end
# end
# end
#
# @example Define the invokation block anywhere you want
# def subcommands(cmd)
# cmd.command :download do |opt|
# description 'Downloads a content from a server'
#
# opt.on :verbose, 'Use verbose output'
# end
# end
#
# def process
# # Perform calculations...
# opts.fetch_command(:download).run do |options, arguments|
# ContentDownloader.download(options, arguments)
# end
# # More calculations...
# end
def subcommands(cmd); end
# A method to setup Slop so it can parse the options your command expects.
#
# @note Please don't do anything side-effecty in the main part of this
# method, as it may be called by Pry at any time for introspection reasons.
# If you need to set up default values, use `setup` instead.
#
# @example
# def options(opt)
# opt.banner "Gists methods or classes"
# opt.on(:c, :class, "gist a class") do
# @action = :class
# end
# end
def options(opt); end
# The actual body of your command should go here.
#
# The `opts` mehod can be called to get the options that Slop has passed,
# and `args` gives the remaining, unparsed arguments.
#
# The return value of this method is discarded unless the command was
# created with `:keep_retval => true`, in which case it is returned to the
# repl.
#
# @example
# def process
# if opts.present?(:class)
# gist_class
# else
# gist_method
# end
# end
def process; raise CommandError, "command '#{command_name}' not implemented" end
end
end