Contents

# typed: true
# frozen_string_literal: true

require "packwerk/constant_name_inspector"

module Packwerk
  # Extracts a constant name from an AST node of type :const
  class ConstNodeInspector
    include ConstantNameInspector

    def constant_name_from_node(node, ancestors:)
      return nil unless Node.constant?(node)
      parent = ancestors.first
      return nil unless root_constant?(parent)

      if parent && constant_in_module_or_class_definition?(node, parent: parent)
        fully_qualify_constant(node, ancestors: ancestors)
      else
        begin
          Node.constant_name(node)
        rescue Node::TypeError
          nil
        end
      end
    end

    private

    # Only process the root `const` node for namespaced constant references. For example, in the
    # reference `Spam::Eggs::Thing`, we only process the const node associated with `Spam`.
    def root_constant?(parent)
      !(parent && Node.constant?(parent))
    end

    def constant_in_module_or_class_definition?(node, parent:)
      parent_name = Node.module_name_from_definition(parent)
      parent_name && parent_name == Node.constant_name(node)
    end

    def fully_qualify_constant(node, ancestors:)
      # We're defining a class with this name, in which case the constant is implicitly fully qualified by its
      # enclosing namespace
      name = Node.parent_module_name(ancestors: ancestors)
      name ||= generate_qualified_constant(node, ancestors)
      "::" + name
    end

    def generate_qualified_constant(node, ancestors:)
      namespace_path = Node.enclosing_namespace_path(node, ancestors: ancestors)
      constant_name = Node.constant_name(node)
      namespace_path.push(constant_name).join("::")
    end
  end
end

Version data entries

3 entries across 3 versions & 1 rubygems

Version	Path
packwerk-1.1.1	lib/packwerk/const_node_inspector.rb
packwerk-1.1.0	lib/packwerk/const_node_inspector.rb
packwerk-1.0.2	lib/packwerk/const_node_inspector.rb