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pry--pry/lib/pry/method.rb

569 lines
20 KiB
Ruby

# -*- coding: utf-8 -*-
require 'pry/helpers/documentation_helpers'
class Pry
class << self
# If the given object is a `Pry::Method`, return it unaltered. If it's
# anything else, return it wrapped in a `Pry::Method` instance.
def Method(obj)
if obj.is_a? Pry::Method
obj
else
Pry::Method.new(obj)
end
end
end
# This class wraps the normal `Method` and `UnboundMethod` classes
# to provide extra functionality useful to Pry.
class Method
include RbxMethod if Helpers::BaseHelpers.rbx?
include Helpers::DocumentationHelpers
class << self
# Given a string representing a method name and optionally a binding to
# search in, find and return the requested method wrapped in a `Pry::Method`
# instance.
#
# @param [String, nil] name The name of the method to retrieve, or `nil` to
# delegate to `from_binding` instead.
# @param [Binding] target The context in which to search for the method.
# @param [Hash] options
# @option options [Boolean] :instance Look for an instance method if `name` doesn't
# contain any context.
# @option options [Boolean] :methods Look for a bound/singleton method if `name` doesn't
# contain any context.
# @return [Pry::Method, nil] A `Pry::Method` instance containing the requested
# method, or `nil` if no method could be located matching the parameters.
def from_str(name, target=TOPLEVEL_BINDING, options={})
if name.nil?
from_binding(target)
elsif name.to_s =~ /(.+)\#(\S+)\Z/
context, meth_name = $1, $2
from_module(target.eval(context), meth_name)
elsif name.to_s =~ /(.+)\.(\S+)\Z/
context, meth_name = $1, $2
from_obj(target.eval(context), meth_name)
elsif options[:instance]
from_module(target.eval("self"), name)
elsif options[:methods]
from_obj(target.eval("self"), name)
else
from_str(name, target, :instance => true) or
from_str(name, target, :methods => true)
end
end
# Given a `Binding`, try to extract the `::Method` it originated from and
# use it to instantiate a `Pry::Method`. Return `nil` if this isn't
# possible.
#
# @param [Binding] b
# @return [Pry::Method, nil]
#
def from_binding(b)
meth_name = b.eval('::Kernel.__method__')
if [:__script__, nil].include?(meth_name)
nil
else
method = begin
if Object === b.eval('self')
new(Kernel.instance_method(:method).bind(b.eval("self")).call(meth_name))
else
new(b.eval('class << self; self; end.instance_method(::Kernel.__method__).bind(self)'))
end
rescue NameError, NoMethodError
Disowned.new(b.eval('self'), meth_name.to_s)
end
# it's possible in some cases that the method we find by this approach is a sub-method of
# the one we're currently in, consider:
#
# class A; def b; binding.pry; end; end
# class B < A; def b; super; end; end
#
# Given that we can normally find the source_range of methods, and that we know which
# __FILE__ and __LINE__ the binding is at, we can hope to disambiguate these cases.
#
# This obviously won't work if the source is unavaiable for some reason, or if both
# methods have the same __FILE__ and __LINE__, or if we're in rbx where b.eval('__LINE__')
# is broken.
#
guess = method
while guess
# needs rescue if this is a Disowned method or a C method or something...
# TODO: Fix up the exception handling so we don't need a bare rescue
if (guess.source_file && guess.source_range rescue false) &&
File.expand_path(guess.source_file) == File.expand_path(b.eval('__FILE__')) &&
guess.source_range.include?(b.eval('__LINE__'))
return guess
else
guess = guess.super
end
end
# Uhoh... none of the methods in the chain had the right __FILE__ and __LINE__
# This may be caused by rbx https://github.com/rubinius/rubinius/issues/953,
# or other unknown circumstances (TODO: we should warn the user when this happens)
method
end
end
# Given a `Class` or `Module` and the name of a method, try to
# instantiate a `Pry::Method` containing the instance method of
# that name. Return `nil` if no such method exists.
#
# @param [Class, Module] klass
# @param [String] name
# @return [Pry::Method, nil]
def from_class(klass, name)
new(safe_send(klass, :instance_method, name)) rescue nil
end
alias from_module from_class
# Given an object and the name of a method, try to instantiate
# a `Pry::Method` containing the method of that name bound to
# that object. Return `nil` if no such method exists.
#
# @param [Object] obj
# @param [String] name
# @return [Pry::Method, nil]
def from_obj(obj, name)
new(safe_send(obj, :method, name)) rescue nil
end
# Get all of the instance methods of a `Class` or `Module`
# @param [Class,Module] klass
# @param [Boolean] include_super Whether to include methods from ancestors.
# @return [Array[Pry::Method]]
def all_from_class(klass, include_super=true)
all_from_common(klass, :instance_method, include_super)
end
# Get all of the methods on an `Object`
# @param [Object] obj
# @param [Boolean] include_super Whether to include methods from ancestors.
# @return [Array[Pry::Method]]
def all_from_obj(obj, include_super=true)
all_from_common(obj, :method, include_super)
end
# Get every `Class` and `Module`, in order, that will be checked when looking
# for an instance method to call on this object.
# @param [Object] obj
# @return [Array[Class, Module]]
def resolution_order(obj)
if Class === obj
singleton_class_resolution_order(obj) + instance_resolution_order(Class)
else
klass = singleton_class(obj) rescue obj.class
instance_resolution_order(klass)
end
end
# Get every `Class` and `Module`, in order, that will be checked when looking
# for methods on instances of the given `Class` or `Module`.
# This does not treat singleton classes of classes specially.
# @param [Class, Module] klass
# @return [Array[Class, Module]]
def instance_resolution_order(klass)
# include klass in case it is a singleton class,
([klass] + klass.ancestors).uniq
end
private
# See all_from_class and all_from_obj.
# If method_type is :instance_method, obj must be a `Class` or a `Module`
# If method_type is :method, obj can be any `Object`
#
# N.B. we pre-cache the visibility here to avoid O(N²) behaviour in "ls".
def all_from_common(obj, method_type, include_super=true)
%w(public protected private).map do |visibility|
safe_send(obj, :"#{visibility}_#{method_type}s", include_super).map do |method_name|
new(safe_send(obj, method_type, method_name), :visibility => visibility.to_sym)
end
end.flatten(1)
end
# Acts like send but ignores any methods defined below Object or Class in the
# inheritance hierarchy.
# This is required to introspect methods on objects like Net::HTTP::Get that
# have overridden the `method` method.
def safe_send(obj, method, *args, &block)
(Module === obj ? Module : Object).instance_method(method).bind(obj).call(*args, &block)
end
public :safe_send
# Get the singleton classes of superclasses that could define methods on
# the given class object, and any modules they include.
# If a module is included at multiple points in the ancestry, only
# the lowest copy will be returned.
def singleton_class_resolution_order(klass)
resolution_order = klass.ancestors.map do |anc|
[singleton_class(anc)] + singleton_class(anc).included_modules if anc.is_a?(Class)
end.compact.flatten(1)
resolution_order.reverse.uniq.reverse - Class.included_modules
end
def singleton_class(obj); class << obj; self; end end
end
# A new instance of `Pry::Method` wrapping the given `::Method`, `UnboundMethod`, or `Proc`.
#
# @param [::Method, UnboundMethod, Proc] method
# @param [Hash] known_info Can be used to pre-cache expensive to compute stuff.
# @return [Pry::Method]
def initialize(method, known_info={})
@method = method
@visibility = known_info[:visibility]
end
# Get the name of the method as a String, regardless of the underlying Method#name type.
# @return [String]
def name
@method.name.to_s
end
# Get the owner of the method as a Pry::Module
# @return [Pry::Module]
def wrapped_owner
@wrapped_owner ||= Pry::WrappedModule.new(owner)
end
# Is the method undefined? (aka `Disowned`)
# @return [Boolean] false
def undefined?
false
end
# Get the name of the method including the class on which it was defined.
# @example
# method(:puts).method_name
# => "Kernel.puts"
# @return [String]
def name_with_owner
"#{wrapped_owner.method_prefix}#{name}"
end
# @return [String, nil] The source code of the method, or `nil` if it's unavailable.
def source
@source ||= case source_type
when :c
info = pry_doc_info
if info and info.source
code = strip_comments_from_c_code(info.source)
end
when :ruby
# clone of MethodSource.source_helper that knows to use our
# hacked version of source_location for rbx core methods, and
# our input buffer for methods defined in (pry)
file, line = *source_location
raise SourceNotFoundError, "Could not locate source for #{name_with_owner}!" unless file
begin
code = Pry::Code.from_file(file).expression_at(line)
rescue SyntaxError => e
raise MethodSource::SourceNotFoundError.new(e.message)
end
strip_leading_whitespace(code)
end
end
# Can we get the source code for this method?
# @return [Boolean]
def source?
!!source
rescue MethodSource::SourceNotFoundError
false
end
# @return [String, nil] The documentation for the method, or `nil` if it's
# unavailable.
# @raise [CommandError] Raises when the method was defined in the REPL.
def doc
@doc ||= case source_type
when :c
info = pry_doc_info
info.docstring if info
when :ruby
if Helpers::BaseHelpers.rbx? && !pry_method?
strip_leading_hash_and_whitespace_from_ruby_comments(core_doc)
elsif pry_method?
strip_leading_hash_and_whitespace_from_ruby_comments(doc_for_pry_method)
else
strip_leading_hash_and_whitespace_from_ruby_comments(@method.comment)
end
end
end
# @return [Symbol] The source type of the method. The options are
# `:ruby` for Ruby methods or `:c` for methods written in C.
def source_type
source_location.nil? ? :c : :ruby
end
def source_location
if @method.source_location && Helpers::BaseHelpers.rbx?
file, line = @method.source_location
[RbxPath.convert_path_to_full(file), line]
else
@method.source_location
end
end
# @return [String, nil] The name of the file the method is defined in, or
# `nil` if the filename is unavailable.
def source_file
if source_location.nil?
if !Helpers::BaseHelpers.rbx? and source_type == :c
info = pry_doc_info
info.file if info
end
else
source_location.first
end
end
# @return [Fixnum, nil] The line of code in `source_file` which begins
# the method's definition, or `nil` if that information is unavailable.
def source_line
source_location.nil? ? nil : source_location.last
end
# @return [Range, nil] The range of lines in `source_file` which contain
# the method's definition, or `nil` if that information is unavailable.
def source_range
source_location.nil? ? nil : (source_line)..(source_line + source.lines.count - 1)
end
# @return [Symbol] The visibility of the method. May be `:public`,
# `:protected`, or `:private`.
def visibility
@visibility ||= if owner.public_instance_methods.any? { |m| m.to_s == name }
:public
elsif owner.protected_instance_methods.any? { |m| m.to_s == name }
:protected
elsif owner.private_instance_methods.any? { |m| m.to_s == name }
:private
else
:none
end
end
# @return [String] A representation of the method's signature, including its
# name and parameters. Optional and "rest" parameters are marked with `*`
# and block parameters with `&`. If the parameter names are unavailable,
# they're given numbered names instead.
# Paraphrased from `awesome_print` gem.
def signature
if respond_to?(:parameters)
args = parameters.inject([]) do |arr, (type, name)|
name ||= (type == :block ? 'block' : "arg#{arr.size + 1}")
arr << case type
when :req then name.to_s
when :opt then "#{name}=?"
when :rest then "*#{name}"
when :block then "&#{name}"
else '?'
end
end
else
args = (1..arity.abs).map { |i| "arg#{i}" }
args[-1] = "*#{args[-1]}" if arity < 0
end
"#{name}(#{args.join(', ')})"
end
# @return [Pry::Method, nil] The wrapped method that is called when you
# use "super" in the body of this method.
def super(times=1)
if UnboundMethod === @method
sup = super_using_ancestors(Pry::Method.instance_resolution_order(owner), times)
else
sup = super_using_ancestors(Pry::Method.resolution_order(receiver), times)
sup &&= sup.bind(receiver)
end
Pry::Method.new(sup) if sup
end
# @return [String, nil] The original name the method was defined under,
# before any aliasing, or `nil` if it can't be determined.
def original_name
return nil if source_type != :ruby
method_name_from_first_line(source.lines.first)
end
# @return [Boolean] Was the method defined outside a source file?
def dynamically_defined?
!!(source_file and source_file =~ /(\(.*\))|<.*>/)
end
# @return [Boolean] Was the method defined within the Pry REPL?
def pry_method?
source_file == Pry.eval_path
end
# @return [Array<String>] All known aliases for the method.
# @note On Ruby 1.8 this method always returns an empty Array for methods
# implemented in C.
def aliases
owner = @method.owner
# Avoid using `to_sym` on {Method#name}, which returns a `String`, because
# it won't be garbage collected.
name = @method.name
alias_list = owner.instance_methods.combination(2).select do |pair|
pair.include?(name) &&
owner.instance_method(pair.first) == owner.instance_method(pair.last)
end.flatten
alias_list.delete(name)
alias_list.map(&:to_s)
end
# @return [Boolean] Is the method definitely an alias?
def alias?
name != original_name
end
# @return [Boolean]
def ==(obj)
if obj.is_a? Pry::Method
obj == @method
else
@method == obj
end
end
# @param [Class] klass
# @return [Boolean]
def is_a?(klass)
klass == Pry::Method or @method.is_a?(klass)
end
alias kind_of? is_a?
# @param [String, Symbol] method_name
# @return [Boolean]
def respond_to?(method_name)
super or @method.respond_to?(method_name)
end
# Delegate any unknown calls to the wrapped method.
def method_missing(method_name, *args, &block)
@method.send(method_name, *args, &block)
end
private
# @return [YARD::CodeObjects::MethodObject]
# @raise [CommandError] Raises when the method can't be found or `pry-doc` isn't installed.
def pry_doc_info
if Pry.config.has_pry_doc
Pry::MethodInfo.info_for(@method) or raise CommandError, "Cannot locate this method: #{name}. (source_location returns nil)"
else
raise CommandError, "Cannot locate this method: #{name}. Try `gem install pry-doc` to get access to Ruby Core documentation."
end
end
# FIXME: a very similar method to this exists on WrappedModule: extract_doc_for_candidate
def doc_for_pry_method
_, line_num = source_location
buffer = ""
Pry.line_buffer[0..(line_num - 1)].each do |line|
# Add any line that is a valid ruby comment,
# but clear as soon as we hit a non comment line.
if (line =~ /^\s*#/) || (line =~ /^\s*$/)
buffer << line.lstrip
else
buffer.replace("")
end
end
buffer
end
# @param [Class, Module] ancestors The ancestors to investigate
# @return [Method] The unwrapped super-method
def super_using_ancestors(ancestors, times=1)
next_owner = self.owner
times.times do
i = ancestors.index(next_owner) + 1
while ancestors[i] && !(ancestors[i].method_defined?(name) || ancestors[i].private_method_defined?(name))
i += 1
end
next_owner = ancestors[i] or return nil
end
next_owner.instance_method(name) rescue nil
end
# @param [String] first_ln The first line of a method definition.
# @return [String, nil]
def method_name_from_first_line(first_ln)
return nil if first_ln.strip !~ /^def /
tokens = CodeRay.scan(first_ln, :ruby)
tokens = tokens.tokens.each_slice(2) if tokens.respond_to?(:tokens)
tokens.each_cons(2) do |t1, t2|
if t2.last == :method || t2.last == :ident && t1 == [".", :operator]
return t2.first
end
end
nil
end
# A Disowned Method is one that's been removed from the class on which it was defined.
#
# e.g.
# class C
# def foo
# C.send(:undefine_method, :foo)
# Pry::Method.from_binding(binding)
# end
# end
#
# In this case we assume that the "owner" is the singleton class of the receiver.
#
# This occurs mainly in Sinatra applications.
class Disowned < Method
attr_reader :receiver, :name
# Create a new Disowned method.
#
# @param [Object] receiver
# @param [String] method_name
def initialize(receiver, method_name)
@receiver, @name = receiver, method_name
end
# Is the method undefined? (aka `Disowned`)
# @return [Boolean] true
def undefined?
true
end
# Can we get the source for this method?
# @return [Boolean] false
def source?
false
end
# Get the hypothesized owner of the method.
#
# @return [Object]
def owner
class << receiver; self; end
end
# Raise a more useful error message instead of trying to forward to nil.
def method_missing(meth_name, *args, &block)
raise "Cannot call '#{meth_name}' on an undef'd method." if method(:name).respond_to?(meth_name)
Object.instance_method(:method_missing).bind(self).call(meth_name, *args, &block)
end
end
end
end