Module: Canon::Comparison::XmlNodeComparison

Defined in:
lib/canon/comparison/xml_node_comparison.rb

Overview

XML Node Comparison Utilities

Provides public comparison methods for XML/HTML nodes. This module extracts shared comparison logic that was previously accessed via send() from HtmlComparator.

Class Method Summary collapse

Class Method Details

.add_difference(node1, node2, diff1, diff2, dimension, opts, differences) ⇒ Object

Add a difference to the differences array

Parameters:

  • node1 (Object) —

    First node

  • node2 (Object) —

    Second node

  • diff1 (Symbol) —

    Difference type for node1

  • diff2 (Symbol) —

    Difference type for node2

  • dimension (Symbol) —

    The dimension of the difference

  • opts (Hash) —

    Comparison options

  • differences (Array) —

    Array to append difference to



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 271

def self.add_difference(node1, node2, diff1, diff2, dimension, opts,
differences)
  return unless opts[:verbose]

  require_relative "xml_comparator"
  XmlComparator.add_difference(node1, node2, diff1, diff2, dimension,
                               opts, differences)
end

.comment_node?(node) ⇒ Boolean

Check if a node is a comment node

Parameters:

  • node (Object) —

    Node to check

Returns:

  • (Boolean) —

    true if node is a comment



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 176

def self.comment_node?(node)
  node.respond_to?(:comment?) && node.comment? ||
    node.respond_to?(:node_type) && node.node_type == :comment
end

.compare_document_fragments(node1, node2, opts, child_opts, diff_children, differences) ⇒ Symbol

Compare document fragments by comparing their children

Parameters:

  • node1 (Nokogiri::XML::DocumentFragment) —

    First fragment

  • node2 (Nokogiri::XML::DocumentFragment) —

    Second fragment

  • opts (Hash) —

    Comparison options

  • child_opts (Hash) —

    Options for child comparison

  • diff_children (Boolean) —

    Whether to diff children

  • differences (Array) —

    Array to append differences to

Returns:

  • (Symbol) —

    Comparison result constant



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 79

def self.compare_document_fragments(node1, node2, opts, child_opts,
                                    diff_children, differences)
  childrenode1 = node1.children.to_a
  childrenode2 = node2.children.to_a

  if childrenode1.length != childrenode2.length
    add_difference(node1, node2, Comparison::UNEQUAL_ELEMENTS,
                   Comparison::UNEQUAL_ELEMENTS, :text_content, opts,
                   differences)
    Comparison::UNEQUAL_ELEMENTS
  elsif childrenode1.empty?
    Comparison::EQUIVALENT
  else
    # Compare each pair of children
    result = Comparison::EQUIVALENT
    childrenode1.zip(childrenode2).each do |child1, child2|
      child_result = compare_nodes(child1, child2, opts, child_opts,
                                   diff_children, differences)
      result = child_result unless result == Comparison::EQUIVALENT
    end
    result
  end
end

.compare_nodes(node1, node2, opts, child_opts, diff_children, differences) ⇒ Symbol

Main comparison dispatcher for XML nodes

This method handles the high-level comparison logic, delegating to specific comparison methods based on node types.

Parameters:

  • node1 (Object) —

    First node

  • node2 (Object) —

    Second node

  • opts (Hash) —

    Comparison options

  • child_opts (Hash) —

    Options for child comparison

  • diff_children (Boolean) —

    Whether to diff children

  • differences (Array) —

    Array to append differences to

Returns:

  • (Symbol) —

    Comparison result constant



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 23

def self.compare_nodes(node1, node2, opts, child_opts, diff_children,
differences)
  # Handle DocumentFragment nodes - compare their children instead
  if node1.is_a?(Nokogiri::XML::DocumentFragment) &&
      node2.is_a?(Nokogiri::XML::DocumentFragment)
    return compare_document_fragments(node1, node2, opts, child_opts,
                                      diff_children, differences)
  end

  # Check if nodes should be excluded
  return Comparison::EQUIVALENT if node_excluded?(node1, opts) &&
    node_excluded?(node2, opts)

  if node_excluded?(node1, opts) || node_excluded?(node2, opts)
    add_difference(node1, node2, Comparison::MISSING_NODE,
                   Comparison::MISSING_NODE, :text_content, opts,
                   differences)
    return Comparison::MISSING_NODE
  end

  # Check node types match
  unless same_node_type?(node1, node2)
    add_difference(node1, node2, Comparison::UNEQUAL_NODES_TYPES,
                   Comparison::UNEQUAL_NODES_TYPES, :text_content, opts,
                   differences)
    return Comparison::UNEQUAL_NODES_TYPES
  end

  # Dispatch based on node type
  dispatch_by_node_type(node1, node2, opts, child_opts, diff_children,
                        differences)
end

.dispatch_by_node_type(node1, node2, opts, child_opts, diff_children, differences) ⇒ Symbol

Dispatch comparison based on node type

Parameters:

  • node1 (Object) —

    First node

  • node2 (Object) —

    Second node

  • opts (Hash) —

    Comparison options

  • child_opts (Hash) —

    Options for child comparison

  • diff_children (Boolean) —

    Whether to diff children

  • differences (Array) —

    Array to append differences to

Returns:

  • (Symbol) —

    Comparison result constant



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 112

def self.dispatch_by_node_type(node1, node2, opts, child_opts,
diff_children, differences)
  # Canon::Xml::Node types use .node_type method that returns symbols
  # Nokogiri also has .node_type but returns integers, so check for Symbol
  if node1.respond_to?(:node_type) && node2.respond_to?(:node_type) &&
      node1.node_type.is_a?(Symbol) && node2.node_type.is_a?(Symbol)
    dispatch_canon_node_type(node1, node2, opts, child_opts,
                             diff_children, differences)
  # Moxml/Nokogiri types use .element?, .text?, etc. methods
  else
    dispatch_legacy_node_type(node1, node2, opts, child_opts,
                              diff_children, differences)
  end
end

.dispatch_canon_node_type(node1, node2, opts, child_opts, diff_children, differences) ⇒ Object

Dispatch by Canon::Xml::Node type



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 210

def self.dispatch_canon_node_type(node1, node2, opts, child_opts,
diff_children, differences)
  # Import XmlComparator to use its comparison methods
  require_relative "xml_comparator"

  case node1.node_type
  when :root
    XmlComparator.compare_children(node1, node2, opts, child_opts,
                                   diff_children, differences)
  when :element
    XmlComparator.compare_element_nodes(node1, node2, opts, child_opts,
                                        diff_children, differences)
  when :text
    XmlComparator.compare_text_nodes(node1, node2, opts, differences)
  when :comment
    XmlComparator.compare_comment_nodes(node1, node2, opts, differences)
  when :cdata
    XmlComparator.compare_text_nodes(node1, node2, opts, differences)
  when :processing_instruction
    XmlComparator.compare_processing_instruction_nodes(node1, node2,
                                                       opts, differences)
  else
    Comparison::EQUIVALENT
  end
end

.dispatch_legacy_node_type(node1, node2, opts, child_opts, diff_children, differences) ⇒ Object

Dispatch by legacy Nokogiri/Moxml node type



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 237

def self.dispatch_legacy_node_type(node1, node2, opts, child_opts,
diff_children, differences)
  # Import XmlComparator to use its comparison methods
  require_relative "xml_comparator"

  if node1.respond_to?(:element?) && node1.element?
    XmlComparator.compare_element_nodes(node1, node2, opts, child_opts,
                                        diff_children, differences)
  elsif node1.respond_to?(:text?) && node1.text?
    XmlComparator.compare_text_nodes(node1, node2, opts, differences)
  elsif node1.respond_to?(:comment?) && node1.comment?
    XmlComparator.compare_comment_nodes(node1, node2, opts, differences)
  elsif node1.respond_to?(:cdata?) && node1.cdata?
    XmlComparator.compare_text_nodes(node1, node2, opts, differences)
  elsif node1.respond_to?(:processing_instruction?) && node1.processing_instruction?
    XmlComparator.compare_processing_instruction_nodes(node1, node2,
                                                       opts, differences)
  elsif node1.respond_to?(:root)
    XmlComparator.compare_document_nodes(node1, node2, opts, child_opts,
                                         diff_children, differences)
  else
    Comparison::EQUIVALENT
  end
end

.filter_children(children, opts) ⇒ Array

Filter children based on options

Removes nodes that should be excluded from comparison based on options like :ignore_nodes, :ignore_comments, etc.

Parameters:

  • children (Array) —

    Array of child nodes

  • opts (Hash) —

    Comparison options

Returns:

  • (Array) —

    Filtered array of children



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 64

def self.filter_children(children, opts)
  children.reject do |child|
    node_excluded?(child, opts)
  end
end

.node_excluded?(node, opts) ⇒ Boolean

Check if a node should be excluded from comparison

Parameters:

  • node (Object) —

    Node to check

  • opts (Hash) —

    Comparison options

Returns:

  • (Boolean) —

    true if node should be excluded



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 134

def self.node_excluded?(node, opts)
  return false if node.nil?
  return true if opts[:ignore_nodes]&.include?(node)
  return true if opts[:ignore_comments] && comment_node?(node)
  return true if opts[:ignore_text_nodes] && text_node?(node)

  # Check structural_whitespace match option
  match_opts = opts[:match_opts]
  return false unless match_opts

  # Filter out whitespace-only text nodes based on structural_whitespace setting
  # - :ignore or :normalize: Filter all whitespace-only text nodes
  # - :strict: Preserve all whitespace-only text nodes (don't filter any)
  if text_node?(node) && %i[ignore
                            normalize].include?(match_opts[:structural_whitespace])
    text = node_text(node)
    return true if MatchOptions.normalize_text(text).empty?
  end

  false
end

.node_text(node) ⇒ String

Extract text content from a node

Parameters:

  • node (Object) —

    Node to extract text from

Returns:

  • (String) —

    Text content



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 195

def self.node_text(node)
  return "" unless node

  if node.respond_to?(:content)
    node.content.to_s
  elsif node.respond_to?(:text)
    node.text.to_s
  elsif node.respond_to?(:value)
    node.value.to_s
  else
    ""
  end
end

.same_node_type?(node1, node2) ⇒ Boolean

Check if two nodes are of the same type

Parameters:

  • node1 (Object) —

    First node

  • node2 (Object) —

    Second node

Returns:

  • (Boolean) —

    true if nodes are same type



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 161

def self.same_node_type?(node1, node2)
  return false if node1.class != node2.class

  # For Nokogiri/Canon::Xml nodes, check node type
  if node1.respond_to?(:node_type) && node2.respond_to?(:node_type)
    node1.node_type == node2.node_type
  else
    true
  end
end

.serialize_node_to_xml(node) ⇒ String

Serialize a Canon::Xml::Node to XML string

This utility method handles serialization of different node types to their string representation for display and debugging purposes.

Parameters:

Returns:

  • (String) —

    XML string representation



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 287

def self.serialize_node_to_xml(node)
  if node.is_a?(Canon::Xml::Nodes::RootNode)
    # Serialize all children of root
    node.children.map { |child| serialize_node_to_xml(child) }.join
  elsif node.is_a?(Canon::Xml::Nodes::ElementNode)
    # Serialize element with attributes and children
    attrs = node.attribute_nodes.map do |a|
      " #{a.name}=\"#{a.value}\""
    end.join
    children_xml = node.children.map do |c|
      serialize_node_to_xml(c)
    end.join

    if children_xml.empty?
      "<#{node.name}#{attrs}/>"
    else
      "<#{node.name}#{attrs}>#{children_xml}</#{node.name}>"
    end
  elsif node.is_a?(Canon::Xml::Nodes::TextNode)
    node.value
  elsif node.is_a?(Canon::Xml::Nodes::CommentNode)
    "<!--#{node.value}-->"
  elsif node.is_a?(Canon::Xml::Nodes::ProcessingInstructionNode)
    "<?#{node.target} #{node.data}?>"
  elsif node.respond_to?(:to_xml)
    node.to_xml
  else
    node.to_s
  end
end

.text_node?(node) ⇒ Boolean

Check if a node is a text node

Parameters:

  • node (Object) —

    Node to check

Returns:

  • (Boolean) —

    true if node is a text node



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# File 'lib/canon/comparison/xml_node_comparison.rb', line 185

def self.text_node?(node)
  node.respond_to?(:text?) && node.text? &&
    !node.respond_to?(:element?) ||
    node.respond_to?(:node_type) && node.node_type == :text
end