Class: Diffy::Diff

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/diffy/diff.rb

Constant Summary collapse

ORIGINAL_DEFAULT_OPTIONS = 
{
  :diff => '-U10000',
  :source => 'strings',
  :include_diff_info => false,
  :include_plus_and_minus_in_html => false,
  :context => nil,
  :allow_empty_diff => true,
}

Class Attribute Summary collapse

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(string1, string2, options = {}) ⇒ Diff

supported options

:diff

A cli options string passed to diff

:source

Either strings or files. Determines whether string1 and string2 should be interpreted as strings or file paths.

:include_diff_info

Include diff header info

:include_plus_and_minus_in_html

Show the +, -, ‘ ’ at the beginning of lines in html output.



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# File 'lib/diffy/diff.rb', line 35

def initialize(string1, string2, options = {})
  @options = self.class.default_options.merge(options)
  if ! ['strings', 'files'].include?(@options[:source])
    raise ArgumentError, "Invalid :source option #{@options[:source].inspect}. Supported options are 'strings' and 'files'."
  end
  @string1, @string2 = string1, string2
end

Class Attribute Details

.default_format ⇒ Object 



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# File 'lib/diffy/diff.rb', line 14

def default_format
  @default_format ||= :text
end

.default_options ⇒ Object 



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# File 'lib/diffy/diff.rb', line 20

def default_options
  @default_options ||= ORIGINAL_DEFAULT_OPTIONS.dup
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/diffy/diff.rb', line 26

def options
  @options
end

#string1 ⇒ Object (readonly)

Returns the value of attribute string1.



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# File 'lib/diffy/diff.rb', line 26

def string1
  @string1
end

#string2 ⇒ Object (readonly)

Returns the value of attribute string2.



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# File 'lib/diffy/diff.rb', line 26

def string2
  @string2
end

Instance Method Details

#diff ⇒ Object 



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# File 'lib/diffy/diff.rb', line 43

def diff
  @diff ||= begin
    @paths = case options[:source]
      when 'strings'
        [tempfile(string1), tempfile(string2)]
      when 'files'
        [string1, string2]
      end

    diff, _stderr, _process_status = Open3.capture3(diff_bin, *(diff_options + @paths))
    diff.force_encoding('ASCII-8BIT') if diff.respond_to?(:valid_encoding?) && !diff.valid_encoding?
    if diff =~ /\A\s*\Z/ && !options[:allow_empty_diff]
      diff = case options[:source]
      when 'strings' then string1
      when 'files' then File.read(string1)
      end.gsub(/^/, " ")
    end
    diff
  end
ensure
  # unlink the tempfiles explicitly now that the diff is generated
  if defined? @tempfiles # to avoid Ruby warnings about undefined ins var.
    Array(@tempfiles).each do |t|
      begin
        # check that the path is not nil and file still exists.
        # REE seems to be very agressive with when it magically removes
        # tempfiles
        t.unlink if t.path && File.exist?(t.path)
      rescue => e
        warn "#{e.class}: #{e}"
        warn e.backtrace.join("\n")
      end
    end
  end
end

#each ⇒ Object 



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# File 'lib/diffy/diff.rb', line 79

def each
  lines = case @options[:include_diff_info]
  when false
    # this "primes" the diff and sets up the paths we'll reference below.
    diff

    # caching this regexp improves the performance of the loop by a
    # considerable amount.
    regexp = /^(--- "?#{@paths[0]}"?|\+\+\+ "?#{@paths[1]}"?|@@|\\\\)/

    diff.split("\n").reject{|x| x =~ regexp }.map {|line| line + "\n" }

  when true
    diff.split("\n").map {|line| line + "\n" }
  end

  if block_given?
    lines.each{|line| yield line}
  else
    lines.to_enum
  end
end

#each_chunk ⇒ Object 



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# File 'lib/diffy/diff.rb', line 102

def each_chunk
  old_state = nil
  chunks = inject([]) do |cc, line|
    state = line.each_char.first
    if state == old_state
      cc.last << line
    else
      cc.push line.dup
    end
    old_state = state
    cc
  end

  if block_given?
    chunks.each{|chunk| yield chunk }
  else
    chunks.to_enum
  end
end

#tempfile(string) ⇒ Object 



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# File 'lib/diffy/diff.rb', line 122

def tempfile(string)
  t = Tempfile.new('diffy')
  # ensure tempfiles aren't unlinked when GC runs by maintaining a
  # reference to them.
  @tempfiles ||=[]
  @tempfiles.push(t)
  t.print(string)
  t.flush
  t.close
  t.path
end

#to_s(format = nil) ⇒ Object 



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# File 'lib/diffy/diff.rb', line 134

def to_s(format = nil)
  format ||= self.class.default_format
  formats = Format.instance_methods(false).map{|x| x.to_s}
  if formats.include? format.to_s
    enum = self
    enum.extend Format
    enum.send format
  else
    raise ArgumentError,
      "Format #{format.inspect} not found in #{formats.inspect}"
  end
end