Class: Ruby::Merge::RescueSemantics

Inherits:
Object
  • Object
show all
Defined in:
lib/ruby/merge/rescue_semantics.rb

Instance Method Summary collapse

Constructor Details

#initialize(source_defined_exception_definitions: []) ⇒ RescueSemantics

Returns a new instance of RescueSemantics.



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# File 'lib/ruby/merge/rescue_semantics.rb', line 6

def initialize(source_defined_exception_definitions: [])
  @source_defined_exception_definitions = source_defined_exception_definitions
end

Instance Method Details

#broad_rescue_clause_type?(clause_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ruby/merge/rescue_semantics.rb', line 86

def broad_rescue_clause_type?(clause_type)
  rescue_clause_type?(clause_type) && clause_type[1] == [:standard_error]
end

#broader_rescue_clause_type_than?(left_clause_type, right_clause_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ruby/merge/rescue_semantics.rb', line 201

def broader_rescue_clause_type_than?(left_clause_type, right_clause_type)
  return false unless rescue_clause_type?(left_clause_type) && rescue_clause_type?(right_clause_type)

  rescue_clause_covers?(left_clause_type, right_clause_type) &&
    !rescue_clause_covers?(right_clause_type, left_clause_type)
end

#canonicalize_begin_clause_kind_order(clause_types) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 67

def canonicalize_begin_clause_kind_order(clause_types)
  clause_types.each_with_index
              .sort_by { |(clause_type, index)| [clause_kind_sort_key(clause_type), index] }
              .map(&:first)
end

#canonicalize_rescue_clause_order(clause_types) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 33

def canonicalize_rescue_clause_order(clause_types)
  rescue_clause_types = clause_types.select { |clause_type| rescue_clause_type?(clause_type) }
  return clause_types if rescue_clause_types.length < 2

  ordered_rescue_types = rescue_clause_types.dup

  if rescue_clause_types.any? { |clause_type| broad_rescue_clause_type?(clause_type) } &&
     rescue_clause_types.any? { |clause_type| !broad_rescue_clause_type?(clause_type) }
    specific_rescue_types = ordered_rescue_types.reject { |clause_type| broad_rescue_clause_type?(clause_type) }
    broad_rescue_types = ordered_rescue_types.select { |clause_type| broad_rescue_clause_type?(clause_type) }
    ordered_rescue_types = specific_rescue_types + broad_rescue_types
  end

  loop do
    swapped = false

    (0...(ordered_rescue_types.length - 1)).each do |index|
      left_clause_type = ordered_rescue_types[index]
      right_clause_type = ordered_rescue_types[index + 1]
      next unless broader_rescue_clause_type_than?(left_clause_type, right_clause_type)

      ordered_rescue_types[index] = right_clause_type
      ordered_rescue_types[index + 1] = left_clause_type
      swapped = true
    end

    break unless swapped
  end

  clause_types.map do |clause_type|
    rescue_clause_type?(clause_type) ? ordered_rescue_types.shift : clause_type
  end
end

#clause_kind_sort_key(clause_type) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 90

def clause_kind_sort_key(clause_type)
  return 0 if rescue_clause_type?(clause_type)
  return 1 if clause_type == :else_clause
  return 2 if clause_type == :ensure_clause

  3
end

#exception_constant_covers?(covering_constant, covered_constant) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ruby/merge/rescue_semantics.rb', line 155

def exception_constant_covers?(covering_constant, covered_constant)
  return true if covering_constant == covered_constant

  covered_constant < covering_constant
rescue StandardError
  false
end

#exception_name_covers?(covering_name, covered_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ruby/merge/rescue_semantics.rb', line 176

def exception_name_covers?(covering_name, covered_name)
  covering_constant = resolve_exception_constant(covering_name)
  covered_constant = resolve_exception_constant(covered_name)

  if covering_constant && covered_constant
    exception_constant_covers?(covering_constant, covered_constant)
  else
    source_defined_exception_covers?(covering_name, covered_name)
  end
end

#merge_ordered_clause_types(primary_types, secondary_types) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 10

def merge_ordered_clause_types(primary_types, secondary_types)
  ordered = primary_types.dup

  secondary_types.each_with_index do |clause_type, secondary_index|
    next if ordered.include?(clause_type)

    previous_shared = secondary_types[0...secondary_index].reverse.find { |type| ordered.include?(type) }
    next_shared = secondary_types[(secondary_index + 1)..]&.find { |type| ordered.include?(type) }

    if previous_shared
      insert_at = ordered.index(previous_shared) + 1
      ordered.insert(insert_at, clause_type)
    elsif next_shared
      insert_at = ordered.index(next_shared)
      ordered.insert(insert_at, clause_type)
    else
      ordered << clause_type
    end
  end

  ordered
end

#normalize_exception_name(exception_name) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 98

def normalize_exception_name(exception_name)
  return 'StandardError' if exception_name == :standard_error

  name = exception_name.to_s.sub(/\A::/, '')
  name.empty? ? nil : name
end

#qualify_source_constant_name(constant_name, namespace = nil) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 105

def qualify_source_constant_name(constant_name, namespace = nil)
  normalized_name = normalize_exception_name(constant_name)
  return if normalized_name.nil?
  return normalized_name if constant_name.to_s.start_with?('::') || namespace.nil? || namespace.empty?

  "#{namespace}::#{normalized_name}"
end

#rescue_clause_covers?(covering_clause_type, covered_clause_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ruby/merge/rescue_semantics.rb', line 187

def rescue_clause_covers?(covering_clause_type, covered_clause_type)
  return false unless rescue_clause_type?(covering_clause_type) && rescue_clause_type?(covered_clause_type)

  covering_names = rescue_clause_exception_names(covering_clause_type)
  covered_names = rescue_clause_exception_names(covered_clause_type)
  return false if covering_names.empty? || covered_names.empty?

  covered_names.all? do |covered_name|
    covering_names.any? do |covering_name|
      exception_name_covers?(covering_name, covered_name)
    end
  end
end

#rescue_clause_exception_constants(clause_type) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 149

def rescue_clause_exception_constants(clause_type)
  rescue_clause_exception_names(clause_type).filter_map do |exception_name|
    resolve_exception_constant(exception_name)
  end
end

#rescue_clause_exception_names(clause_type) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 143

def rescue_clause_exception_names(clause_type)
  return [] unless rescue_clause_type?(clause_type)

  Array(clause_type[1]).filter_map { |exception_name| normalize_exception_name(exception_name) }
end

#rescue_clause_signature(exception_names) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 73

def rescue_clause_signature(exception_names)
  normalized_exceptions = Array(exception_names).filter_map { |exception| normalize_exception_name(exception) }
  if normalized_exceptions.empty? || normalized_exceptions == ['StandardError']
    [:standard_error]
  else
    normalized_exceptions.sort
  end
end

#rescue_clause_type?(clause_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ruby/merge/rescue_semantics.rb', line 82

def rescue_clause_type?(clause_type)
  clause_type.is_a?(Array) && clause_type.first == :rescue_clause
end

#resolve_exception_constant(exception_name) ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 134

def resolve_exception_constant(exception_name)
  return ::StandardError if exception_name == :standard_error
  return unless exception_name.is_a?(String) && !exception_name.empty?

  exception_name.split('::').reject(&:empty?).inject(Object) { |scope, const_name| scope.const_get(const_name) }
rescue NameError
  nil
end

#source_defined_exception_covers?(covering_name, covered_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ruby/merge/rescue_semantics.rb', line 163

def source_defined_exception_covers?(covering_name, covered_name)
  normalized_covering = normalize_exception_name(covering_name)
  current_name = normalize_exception_name(covered_name)
  return false if normalized_covering.nil? || current_name.nil?
  return true if normalized_covering == current_name

  while (current_name = source_defined_exception_hierarchy[current_name])
    return true if current_name == normalized_covering
  end

  false
end

#source_defined_exception_hierarchy ⇒ Object 



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# File 'lib/ruby/merge/rescue_semantics.rb', line 113

def source_defined_exception_hierarchy
  @source_defined_exception_hierarchy ||= begin
    definitions = @source_defined_exception_definitions
    defined_names = definitions.map { |definition| definition[:name] }.compact.to_set

    definitions.each_with_object({}) do |definition, hierarchy|
      next unless definition[:name] && definition[:superclass]

      superclass_name = if definition[:superclass].to_s.start_with?('::')
                          normalize_exception_name(definition[:superclass])
                        else
                          candidate_name = qualify_source_constant_name(definition[:superclass],
                                                                        definition[:namespace])
                          defined_names.include?(candidate_name) ? candidate_name : normalize_exception_name(definition[:superclass])
                        end

      hierarchy[definition[:name]] ||= superclass_name if superclass_name
    end
  end
end