Class: RuboCop::Cop::Performance::BigDecimalWithNumericArgument

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, TargetRubyVersion, AutoCorrector, Base
Instance Chain: self, Base
Inherits:	Base Object Base RuboCop::Cop::Performance::BigDecimalWithNumericArgument
Defined in:	lib/rubocop/cop/performance/big_decimal_with_numeric_argument.rb

Overview

Identifies places where a float argument to BigDecimal should be converted to a string. Initializing from String is faster than from Float for BigDecimal.

Also identifies places where an integer string argument to BigDecimal should be converted to an integer. Initializing from Integer is faster than from String for BigDecimal.

Note

This cop is disabled by default because the performance of initializing with a String and Number differ between versions. Additionally, performance depends on the size of the Number, and if it is an Integer or a Float. Since this is very specific to bigdecimal internals, suggestions from this cop are not unlikely to result in code that performs worse than before.

Examples:

# bad
BigDecimal(1.2, 3, exception: true)
4.5.to_d(6, exception: true)

# good
BigDecimal('1.2', 3, exception: true)
BigDecimal('4.5', 6, exception: true)

# bad
BigDecimal('1', 2)
BigDecimal('4', 6)

# good
BigDecimal(1, 2)
4.to_d(6)

Constant Summary

MSG_FROM_FLOAT_TO_STRING =
# File 'lib/rubocop/cop/performance/big_decimal_with_numeric_argument.rb', line 40
```
'Convert float literal to string and pass it to `BigDecimal`.'
```
MSG_FROM_INTEGER_TO_STRING =
# File 'lib/rubocop/cop/performance/big_decimal_with_numeric_argument.rb', line 41
```
'Convert string literal to integer and pass it to `BigDecimal`.'
```
RESTRICT_ON_SEND =
# File 'lib/rubocop/cop/performance/big_decimal_with_numeric_argument.rb', line 42
```
%i[BigDecimal to_d].freeze
```

Instance Method Summary

#on_send(node)

Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity, Metrics/MethodLength.

Instance Method Details

#on_send(node)

Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity, Metrics/MethodLength

[ GitHub ]

# File 'lib/rubocop/cop/performance/big_decimal_with_numeric_argument.rb', line 53


def on_send(node)
  if (numeric = big_decimal_with_numeric_argument(node))
    if numeric.numeric_type?
      add_offense(numeric, message: MSG_FROM_FLOAT_TO_STRING) do |corrector|
        corrector.wrap(numeric, "'", "'")
      end
    elsif numeric.value.match?(/\A\d+\z/)
      add_offense(numeric, message: MSG_FROM_INTEGER_TO_STRING) do |corrector|
        corrector.replace(numeric, numeric.value)
      end
    end
  elsif (numeric_to_d = to_d(node))
    if numeric_to_d.numeric_type?
      add_offense(numeric_to_d, message: MSG_FROM_FLOAT_TO_STRING) do |corrector|
        big_decimal_args = node.arguments.map(&:source).unshift("'#{numeric_to_d.source}'").join(', ')

        corrector.replace(node, "BigDecimal(#{big_decimal_args})")
      end
    elsif numeric_to_d.value.match?(/\A\d+\z/)
      add_offense(numeric_to_d, message: MSG_FROM_INTEGER_TO_STRING) do |corrector|
        corrector.replace(node, "#{numeric_to_d.value}.to_d")
      end
    end
  end
end