Class: HashDeepDiff::Delta

Inherits:
Object
  • Object
show all
Includes:
ActsAsHash
Defined in:
lib/hash_deep_diff/delta.rb

Overview

Representation of the diff of two values examples:

- diff of { a: a } and {} is { a: { left: a, right: HashDeepDiff::NO_VALUE } }
- diff of { a: a } and { a: b } is { a: { left: a, right: b } }
- diff of {} and { a: b } is { a: { left: HashDeepDiff::NO_VALUE, right: b } }

Instance Method Summary collapse

Methods included from ActsAsHash

included

Constructor Details

#initialize(path:, value:) ⇒ Delta (private)

Returns a new instance of Delta.

Parameters:

  • path (Array, Object) —

    list of keys to fetch values we’re comparing

  • value (Hash<(:left, :right), Object>) —

    Hash object with two keys - :left and :right, that represents compared original value (at :left) and value we compare to (at :right)



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# File 'lib/hash_deep_diff/delta.rb', line 53

def initialize(path:, value:)
  # TOFIX this may prohibit usage of hashes with Array keys
  # TOFIX extract path to a separate object
  if path.respond_to?(:to_ary)
    @delta = { path[-1] => value }
    @value = value
    @prefix = path[0..-2]
  else
    @delta = { path => value }
    @value = value
    @prefix = []
  end
end

Instance Method Details

#addition ⇒ NillClass, String (private)

Visual representation of deletions

Returns:

  • (NillClass, String) 


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# File 'lib/hash_deep_diff/delta.rb', line 77

def addition
  return nil if right == NO_VALUE

  Report.new(path: path, value: right)
end

#complex? ⇒ Bool

Returns true if we have nested Hashes

Returns:

  • (Bool) 


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# File 'lib/hash_deep_diff/delta.rb', line 23

def complex?
  left.respond_to?(:to_hash) && right.respond_to?(:to_hash)
end

#deletion ⇒ NillClass, String (private)

Visual representation of additions

Returns:

  • (NillClass, String) 


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# File 'lib/hash_deep_diff/delta.rb', line 69

def deletion
  return nil if left == NO_VALUE

  Report.new(path: path, value: left, mode: Report::Mode::DELETION)
end

#left ⇒ Object

Original value



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# File 'lib/hash_deep_diff/delta.rb', line 34

def left
  @value[:left]
end

#path ⇒ Array

Keys needed to fetch values that we’re comparing

Returns:

  • (Array) 


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# File 'lib/hash_deep_diff/delta.rb', line 29

def path
  @prefix + [@delta.keys.first]
end

#right ⇒ Object

Value we compare to



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# File 'lib/hash_deep_diff/delta.rb', line 39

def right
  @value[:right]
end

#to_s ⇒ Object

See #to_str



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# File 'lib/hash_deep_diff/delta.rb', line 44

def to_s
  to_str
end

#to_str ⇒ String

Visual representation of additions and deletiond at given path

Returns:

  • (String) 


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# File 'lib/hash_deep_diff/delta.rb', line 17

def to_str
  [deletion, addition].compact.join("\n")
end