Class: Psych::Merge::NodeWrapper

Inherits:
Object
  • Object
show all
Defined in:
lib/psych/merge/node_wrapper.rb

Overview

Wraps Psych::Nodes with comment associations, line information, and signatures. This provides a unified interface for working with YAML nodes during merging.

Examples:

Basic usage

ast = Psych.parse_stream(yaml)
wrapper = NodeWrapper.new(ast.children.first, lines: source.lines)
wrapper.signature # => [:document, ...]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(node, lines:, leading_comments: [], inline_comment: nil, key: nil, comment_tracker: nil, next_sibling_line_num: nil, next_sibling_leading_comments: nil, end_line_limit: nil, **_options) ⇒ NodeWrapper

Returns a new instance of NodeWrapper.

Parameters:

  • node (Psych::Nodes::Node) —

    Psych node to wrap

  • lines (Array<String>) —

    Source lines for content extraction

  • leading_comments (Array<Hash>) (defaults to: []) —

    Comments before this node

  • inline_comment (Hash, nil) (defaults to: nil) —

    Inline comment on the node's line

  • key (String, nil) (defaults to: nil) —

    Key name if this is a mapping value



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# File 'lib/psych/merge/node_wrapper.rb', line 42

def initialize(
  node,
  lines:,
  leading_comments: [],
  inline_comment: nil,
  key: nil,
  comment_tracker: nil,
  next_sibling_line_num: nil,
  next_sibling_leading_comments: nil,
  end_line_limit: nil,
  **_options
)
  @node = node
  @lines = lines
  @leading_comments = leading_comments
  @inline_comment = inline_comment
  @key = key
  @comment_tracker = comment_tracker

  # Extract line information from the Psych node.
  #
  # IMPORTANT: Psych (libyaml) line number semantics:
  # - start_line: 0-based, inclusive (first line of the node's content)
  # - end_line: 0-based, EXCLUSIVE (points to the line AFTER the last content line)
  #
  # Example for a mapping value spanning lines 4-5 (1-based):
  #   Psych reports: start_line=3, end_line=5 (0-based)
  #   - start_line=3 means line 4 (1-based) - correct
  #   - end_line=5 means "up to but not including line 5 (0-based)",
  #     i.e., last included line is 4 (0-based) = line 5 (1-based)
  #
  # Conversion to 1-based inclusive range:
  # - @start_line = node.start_line + 1  (0-based inclusive → 1-based inclusive)
  # - @end_line = node.end_line          (0-based exclusive → 1-based inclusive, since exclusive-1+1=same)
  #
  # If Psych/libyaml ever changes end_line to be inclusive, this will need adjustment.
  # See regression test: "does not duplicate keys when destination adds a new nested mapping"
  @start_line = node.start_line + 1 if node.respond_to?(:start_line) && node.start_line
  @end_line = node.end_line if node.respond_to?(:end_line) && node.end_line

  clamp_end_line_to_next_sibling!(next_sibling_line_num, next_sibling_leading_comments, end_line_limit)

  # Handle edge case where end_line might be before start_line
  @end_line = @start_line if @start_line && @end_line && @end_line < @start_line
end

Instance Attribute Details

#comment_tracker ⇒ CommentTracker? (readonly)

Returns Comment tracker used to associate comments.

Returns:

  • (CommentTracker, nil) —

    Comment tracker used to associate comments



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# File 'lib/psych/merge/node_wrapper.rb', line 35

def comment_tracker
  @comment_tracker
end

#end_line ⇒ Integer (readonly)

Returns End line (1-based).

Returns:

  • (Integer) —

    End line (1-based)



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# File 'lib/psych/merge/node_wrapper.rb', line 26

def end_line
  @end_line
end

#inline_comment ⇒ Hash? (readonly)

Returns Inline/trailing comment on the same line.

Returns:

  • (Hash, nil) —

    Inline/trailing comment on the same line



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# File 'lib/psych/merge/node_wrapper.rb', line 20

def inline_comment
  @inline_comment
end

#key ⇒ String? (readonly)

Returns Key name for mapping entries.

Returns:

  • (String, nil) —

    Key name for mapping entries



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# File 'lib/psych/merge/node_wrapper.rb', line 29

def key
  @key
end

#leading_comments ⇒ Array<Hash> (readonly)

Returns Leading comments associated with this node.

Returns:

  • (Array<Hash>) —

    Leading comments associated with this node



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# File 'lib/psych/merge/node_wrapper.rb', line 17

def leading_comments
  @leading_comments
end

#lines ⇒ Array<String> (readonly)

Returns Source lines.

Returns:

  • (Array<String>) —

    Source lines



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# File 'lib/psych/merge/node_wrapper.rb', line 32

def lines
  @lines
end

#node ⇒ Psych::Nodes::Node (readonly)

Returns The wrapped Psych node.

Returns:

  • (Psych::Nodes::Node) —

    The wrapped Psych node



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# File 'lib/psych/merge/node_wrapper.rb', line 14

def node
  @node
end

#start_line ⇒ Integer (readonly)

Returns Start line (1-based).

Returns:

  • (Integer) —

    Start line (1-based)



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# File 'lib/psych/merge/node_wrapper.rb', line 23

def start_line
  @start_line
end

Instance Method Details

#alias? ⇒ Boolean

Check if this wraps an alias node

Returns:

  • (Boolean) 


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# File 'lib/psych/merge/node_wrapper.rb', line 122

def alias?
  NodeTypeNormalizer.canonical_type(@node.class.name.split('::').last.downcase, :psych) == :alias
end

#alias_anchor ⇒ String?

Get the aliased anchor name

Returns:

  • (String, nil) 


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# File 'lib/psych/merge/node_wrapper.rb', line 195

def alias_anchor
  @node.anchor if alias?
end

#anchor ⇒ String?

Get the anchor name if this node has one

Returns:

  • (String, nil) 


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# File 'lib/psych/merge/node_wrapper.rb', line 128

def anchor
  @node.anchor if @node.respond_to?(:anchor)
end

#children(comment_tracker: nil) ⇒ Array<NodeWrapper>

Get children wrapped as NodeWrappers

Parameters:

  • comment_tracker (CommentTracker) (defaults to: nil) —

    For associating comments with children

Returns:



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# File 'lib/psych/merge/node_wrapper.rb', line 135

def children(comment_tracker: nil)
  return [] unless @node.respond_to?(:children) && @node.children

  wrap_children(@node.children, comment_tracker)
end

#comment_attachment ⇒ Ast::Merge::Comment::Attachment

Get a passive shared comment attachment for this node wrapper.

Returns:

  • (Ast::Merge::Comment::Attachment) 


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# File 'lib/psych/merge/node_wrapper.rb', line 210

def comment_attachment
  @comment_attachment ||= if @comment_tracker
                            @comment_tracker.comment_attachment_for(
                              self,
                              line_num: @start_line,
                              leading_comments: @leading_comments,
                              inline_comment: @inline_comment,
                              key: @key
                            )
                          else
                            Ast::Merge::Comment::Attachment.new(
                              owner: self,
                              leading_region: build_comment_region(:leading, @leading_comments),
                              inline_region: build_comment_region(:inline, [@inline_comment].compact),
                              metadata: { key: @key }
                            )
                          end
end

#content ⇒ String

Get the content for this node from source lines

Returns:

  • (String) 


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# File 'lib/psych/merge/node_wrapper.rb', line 201

def content
  return '' unless @start_line && @end_line

  (@start_line..@end_line).map { |ln| @lines[ln - 1] }.join
end

#freeze_node? ⇒ Boolean

Check if this is a freeze node

Returns:

  • (Boolean) 


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# File 'lib/psych/merge/node_wrapper.rb', line 98

def freeze_node?
  false
end

#inline_comment_region ⇒ Ast::Merge::Comment::Region?

Returns:

  • (Ast::Merge::Comment::Region, nil) 


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# File 'lib/psych/merge/node_wrapper.rb', line 235

def inline_comment_region
  comment_attachment.inline_region
end

#inspect ⇒ String

String representation for debugging

Returns:

  • (String) 


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# File 'lib/psych/merge/node_wrapper.rb', line 249

def inspect
  node_type = @node.class.name.split('::').last
  "#<#{self.class.name} type=#{node_type} lines=#{@start_line}..#{@end_line} key=#{@key.inspect}>"
end

#leading_comment_region ⇒ Ast::Merge::Comment::Region?

Returns:

  • (Ast::Merge::Comment::Region, nil) 


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# File 'lib/psych/merge/node_wrapper.rb', line 230

def leading_comment_region
  comment_attachment.leading_region
end

#mapping? ⇒ Boolean

Check if this wraps a mapping node

Returns:

  • (Boolean) 


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# File 'lib/psych/merge/node_wrapper.rb', line 104

def mapping?
  NodeTypeNormalizer.canonical_type(@node.class.name.split('::').last.downcase, :psych) == :mapping
end

#mapping_entries(comment_tracker: nil) ⇒ Array<Array(NodeWrapper, NodeWrapper)>

Get mapping entries as key-value pairs of NodeWrappers

Parameters:

  • comment_tracker (CommentTracker) (defaults to: nil) —

    For associating comments with children

Returns:



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# File 'lib/psych/merge/node_wrapper.rb', line 144

def mapping_entries(comment_tracker: nil)
  return [] unless mapping?

  entries = []
  children = @node.children
  i = 0
  while i < children.length
    key_node = children[i]
    value_node = children[i + 1]
    break unless key_node && value_node

    key_wrapper = wrap_node(key_node, comment_tracker)
    value_wrapper = wrap_node(
      value_node,
      comment_tracker,
      key: extract_key_name(key_node),
      next_sibling_node: children[i + 2],
      end_line_limit: @end_line
    )

    entries << [key_wrapper, value_wrapper]
    i += 2
  end

  entries
end

#scalar? ⇒ Boolean

Check if this wraps a scalar node

Returns:

  • (Boolean) 


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# File 'lib/psych/merge/node_wrapper.rb', line 116

def scalar?
  NodeTypeNormalizer.canonical_type(@node.class.name.split('::').last.downcase, :psych) == :scalar
end

#sequence? ⇒ Boolean

Check if this wraps a sequence node

Returns:

  • (Boolean) 


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# File 'lib/psych/merge/node_wrapper.rb', line 110

def sequence?
  NodeTypeNormalizer.canonical_type(@node.class.name.split('::').last.downcase, :psych) == :sequence
end

#sequence_items(comment_tracker: nil) ⇒ Array<NodeWrapper>

Get sequence items as NodeWrappers

Parameters:

  • comment_tracker (CommentTracker) (defaults to: nil) —

    For associating comments with children

Returns:



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# File 'lib/psych/merge/node_wrapper.rb', line 174

def sequence_items(comment_tracker: nil)
  return [] unless sequence?

  @node.children.each_with_index.map do |child, index|
    wrap_node(
      child,
      comment_tracker,
      next_sibling_node: @node.children[index + 1],
      end_line_limit: @end_line
    )
  end
end

#signature ⇒ Array?

Generate a signature for this node for matching purposes. Signatures are used to identify corresponding nodes between template and destination.

Returns:

  • (Array, nil) —

    Signature array or nil if not signaturable



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# File 'lib/psych/merge/node_wrapper.rb', line 92

def signature
  compute_signature(@node)
end

#to_s ⇒ String

String representation of the node value. For scalars, returns the value. For other nodes, returns inspect.

Returns:

  • (String) 


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# File 'lib/psych/merge/node_wrapper.rb', line 243

def to_s
  value || inspect
end

#value ⇒ String?

Get the scalar value

Returns:

  • (String, nil) 


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# File 'lib/psych/merge/node_wrapper.rb', line 189

def value
  @node.value if scalar?
end