Class: Spoom::Deadcode::Remover::NodeFinder

Inherits:

Visitor

• Object
• Prism::Visitor
• Visitor
• Spoom::Deadcode::Remover::NodeFinder

Defined in:

lib/spoom/deadcode/remover.rb

Instance Attribute Summary

• #node ⇒ Object readonly
• #nodes_nesting ⇒ Object readonly

Class Method Summary

• .find(source, location, kind) ⇒ Object
• .node_match_kind?(node, kind) ⇒ Boolean

Instance Method Summary

• #initialize(location, kind) ⇒ NodeFinder constructor

  A new instance of NodeFinder.

• #visit(node) ⇒ Object

Methods inherited from Visitor

#visit_alias_global_variable_node, #visit_alias_method_node, #visit_alternation_pattern_node, #visit_and_node, #visit_arguments_node, #visit_array_node, #visit_array_pattern_node, #visit_assoc_node, #visit_assoc_splat_node, #visit_back_reference_read_node, #visit_begin_node, #visit_block_argument_node, #visit_block_local_variable_node, #visit_block_node, #visit_block_parameter_node, #visit_block_parameters_node, #visit_break_node, #visit_call_and_write_node, #visit_call_node, #visit_call_operator_write_node, #visit_call_or_write_node, #visit_call_target_node, #visit_capture_pattern_node, #visit_case_match_node, #visit_case_node, #visit_child_nodes, #visit_class_node, #visit_class_variable_and_write_node, #visit_class_variable_operator_write_node, #visit_class_variable_or_write_node, #visit_class_variable_read_node, #visit_class_variable_target_node, #visit_class_variable_write_node, #visit_constant_and_write_node, #visit_constant_operator_write_node, #visit_constant_or_write_node, #visit_constant_path_and_write_node, #visit_constant_path_node, #visit_constant_path_operator_write_node, #visit_constant_path_or_write_node, #visit_constant_path_target_node, #visit_constant_path_write_node, #visit_constant_read_node, #visit_constant_target_node, #visit_constant_write_node, #visit_def_node, #visit_defined_node, #visit_else_node, #visit_embedded_statements_node, #visit_embedded_variable_node, #visit_ensure_node, #visit_false_node, #visit_find_pattern_node, #visit_flip_flop_node, #visit_float_node, #visit_for_node, #visit_forwarding_arguments_node, #visit_forwarding_parameter_node, #visit_forwarding_super_node, #visit_global_variable_and_write_node, #visit_global_variable_operator_write_node, #visit_global_variable_or_write_node, #visit_global_variable_read_node, #visit_global_variable_target_node, #visit_global_variable_write_node, #visit_hash_node, #visit_hash_pattern_node, #visit_if_node, #visit_imaginary_node, #visit_implicit_node, #visit_implicit_rest_node, #visit_in_node, #visit_index_and_write_node, #visit_index_operator_write_node, #visit_index_or_write_node, #visit_index_target_node, #visit_instance_variable_and_write_node, #visit_instance_variable_operator_write_node, #visit_instance_variable_or_write_node, #visit_instance_variable_read_node, #visit_instance_variable_target_node, #visit_instance_variable_write_node, #visit_integer_node, #visit_interpolated_match_last_line_node, #visit_interpolated_regular_expression_node, #visit_interpolated_string_node, #visit_interpolated_symbol_node, #visit_interpolated_x_string_node, #visit_keyword_hash_node, #visit_keyword_rest_parameter_node, #visit_lambda_node, #visit_local_variable_and_write_node, #visit_local_variable_operator_write_node, #visit_local_variable_or_write_node, #visit_local_variable_read_node, #visit_local_variable_target_node, #visit_local_variable_write_node, #visit_match_last_line_node, #visit_match_predicate_node, #visit_match_required_node, #visit_match_write_node, #visit_missing_node, #visit_module_node, #visit_multi_target_node, #visit_multi_write_node, #visit_next_node, #visit_nil_node, #visit_no_keywords_parameter_node, #visit_numbered_parameters_node, #visit_numbered_reference_read_node, #visit_optional_keyword_parameter_node, #visit_optional_parameter_node, #visit_or_node, #visit_parameters_node, #visit_parentheses_node, #visit_pinned_expression_node, #visit_pinned_variable_node, #visit_post_execution_node, #visit_pre_execution_node, #visit_program_node, #visit_range_node, #visit_rational_node, #visit_redo_node, #visit_regular_expression_node, #visit_required_keyword_parameter_node, #visit_required_parameter_node, #visit_rescue_modifier_node, #visit_rescue_node, #visit_rest_parameter_node, #visit_retry_node, #visit_return_node, #visit_self_node, #visit_singleton_class_node, #visit_source_encoding_node, #visit_source_file_node, #visit_source_line_node, #visit_splat_node, #visit_statements_node, #visit_string_node, #visit_super_node, #visit_symbol_node, #visit_true_node, #visit_undef_node, #visit_unless_node, #visit_until_node, #visit_when_node, #visit_while_node, #visit_x_string_node, #visit_yield_node

Constructor Details

#initialize(location, kind) ⇒ NodeFinder

Returns a new instance of NodeFinder.

Signature:

• (Location location, Definition::Kind? kind) -> void

# File 'lib/spoom/deadcode/remover.rb', line 702

def initialize(location, kind)
  super()
  @location = location
  @kind = kind
  @node = nil #: Prism::Node?
  @nodes_nesting = [] #: Array[Prism::Node]
end

Instance Attribute Details

#node ⇒ Object (readonly)

Signature:

• Prism::Node?

# File 'lib/spoom/deadcode/remover.rb', line 696

def node
  @node
end

#nodes_nesting ⇒ Object (readonly)

Signature:

• Array[Prism::Node]

# File 'lib/spoom/deadcode/remover.rb', line 699

def nodes_nesting
  @nodes_nesting
end

Class Method Details

.find(source, location, kind) ⇒ Object

Signature:

• (String source, Location location, Definition::Kind? kind) -> NodeContext

# File 'lib/spoom/deadcode/remover.rb', line 640

def find(source, location, kind)
  result = Prism.parse(source)

  unless result.success?
    message = result.errors.map do |e|
      "#{e.message} (at #{e.location.start_line}:#{e.location.start_column})."
    end.join(" ")

    raise ParseError, "Error while parsing #{location.file}: #{message}"
  end

  visitor = new(location, kind)
  visitor.visit(result.value)

  node = visitor.node
  unless node
    raise Error, "Can't find node at #{location}"
  end

  if kind && !node_match_kind?(node, kind)
    raise Error, "Can't find node at #{location}, expected #{kind} but got #{node.class}"
  end

  comments_by_line = result.comments.to_h do |comment|
    [comment.location.start_line, comment]
  end #: Hash[Integer, Prism::Comment]

  NodeContext.new(source, comments_by_line, node, visitor.nodes_nesting)
end

.node_match_kind?(node, kind) ⇒ Boolean

Signature:

• (Prism::Node node, Definition::Kind kind) -> bool

Returns:

• (Boolean)

# File 'lib/spoom/deadcode/remover.rb', line 671

def node_match_kind?(node, kind)
  case kind
  when Definition::Kind::AttrReader, Definition::Kind::AttrWriter
    node.is_a?(Prism::SymbolNode)
  when Definition::Kind::Class
    node.is_a?(Prism::ClassNode)
  when Definition::Kind::Constant
    node.is_a?(Prism::ConstantWriteNode) ||
      node.is_a?(Prism::ConstantAndWriteNode) ||
      node.is_a?(Prism::ConstantOrWriteNode) ||
      node.is_a?(Prism::ConstantOperatorWriteNode) ||
      node.is_a?(Prism::ConstantPathWriteNode) ||
      node.is_a?(Prism::ConstantPathAndWriteNode) ||
      node.is_a?(Prism::ConstantPathOrWriteNode) ||
      node.is_a?(Prism::ConstantPathOperatorWriteNode) ||
      node.is_a?(Prism::ConstantTargetNode)
  when Definition::Kind::Method
    node.is_a?(Prism::DefNode)
  when Definition::Kind::Module
    node.is_a?(Prism::ModuleNode)
  end
end

Instance Method Details

#visit(node) ⇒ Object

Signature:

• (Prism::Node? node) -> void

# File 'lib/spoom/deadcode/remover.rb', line 712

def visit(node)
  return unless node

  location = Location.from_prism(@location.file, node.location)

  if location == @location
    # We found the node we're looking for at `@location`
    @node = node

    # The node we found matches the kind we're looking for, we can stop here
    return if @kind && self.class.node_match_kind?(node, @kind)

    # There may be a more precise child inside the node that also matches `@location`, let's visit them
    @nodes_nesting << node
    super(node)
    @nodes_nesting.pop if @nodes_nesting.last == @node
  elsif location.include?(@location)
    # The node we're looking for is inside `node`, let's visit it
    @nodes_nesting << node
    super(node)
  end
end