TracksApp/tracks

Too Many Constants is a special case of LargeClass.

Example

Given this configuration

TooManyConstants:
  max_constants: 3

and this code:

class TooManyConstants
  CONST_1 = :dummy
  CONST_2 = :dummy
  CONST_3 = :dummy
  CONST_4 = :dummy
end

Reek would emit the following warning:

test.rb -- 1 warnings:
  [1]:TooManyConstants has 4 constants (TooManyConstants)

A method with Too Many Statements is any method that has a large number of lines.

Too Many Statements warns about any method that has more than 5 statements. Reek's smell detector for Too Many Statements counts +1 for every simple statement in a method and +1 for every statement within a control structure (if, else, case, when, for, while, until, begin, rescue) but it doesn't count the control structure itself.

So the following method would score +6 in Reek's statement-counting algorithm:

def parse(arg, argv, &error)
  if !(val = arg) and (argv.empty? or /\A-/ =~ (val = argv[0]))
    return nil, block, nil                                         # +1
  end
  opt = (val = parse_arg(val, &error))[1]                          # +2
  val = conv_arg(*val)                                             # +3
  if opt and !arg
    argv.shift                                                     # +4
  else
    val[0] = nil                                                   # +5
  end
  val                                                              # +6
end

(You might argue that the two assigments within the first @if@ should count as statements, and that perhaps the nested assignment should count as +2.)

Classes and modules are the units of reuse and release. It is therefore considered good practice to annotate every class and module with a brief comment outlining its responsibilities.

Example

Given

class Dummy
  # Do things...
end

Reek would emit the following warning:

test.rb -- 1 warning:
  [1]:Dummy has no descriptive comment (IrresponsibleModule)

Fixing this is simple - just an explaining comment:

# The Dummy class is responsible for ...
class Dummy
  # Do things...
end

A Utility Function is any instance method that has no dependency on the state of the instance.

This cop identifies the use of Regexp#match or String#match, which returns #<MatchData>/nil. The return value of =~ is an integral index/nil and is more performant.

Example:

# bad
do_something if str.match(/regex/)
while regex.match('str')
  do_something
end

# good
method(str =~ /regex/)
return value unless regex =~ 'str'

This cop checks for ambiguous regexp literals in the first argument of a method invocation without parentheses.

Example:

# bad

# This is interpreted as a method invocation with a regexp literal,
# but it could possibly be `/` method invocations.
# (i.e. `do_something./(pattern)./(i)`)
do_something /pattern/i

Example:

# good

# With parentheses, there's no ambiguity.
do_something(/pattern/i)

This cop looks for uses of Perl-style regexp match backreferences like $1, $2, etc.

Example:

# bad
puts $1

# good
puts Regexp.last_match(1)

This cop checks for ambiguous regexp literals in the first argument of a method invocation without parentheses.

Example:

# bad

# This is interpreted as a method invocation with a regexp literal,
# but it could possibly be `/` method invocations.
# (i.e. `do_something./(pattern)./(i)`)
do_something /pattern/i

Example:

# good

# With parentheses, there's no ambiguity.
do_something(/pattern/i)

This cop is designed to help upgrade to Ruby 3.0. It will add the comment # frozen_string_literal: true to the top of files to enable frozen string literals. Frozen string literals may be default in Ruby 3.0. The comment will be added below a shebang and encoding comment. The frozen string literal comment is only valid in Ruby 2.3+.

Example: EnforcedStyle: when_needed (default)

# The `when_needed` style will add the frozen string literal comment
# to files only when the `TargetRubyVersion` is set to 2.3+.
# bad
module Foo
  # ...
end

# good
# frozen_string_literal: true

module Foo
  # ...
end

Example: EnforcedStyle: always

# The `always` style will always add the frozen string literal comment
# to a file, regardless of the Ruby version or if `freeze` or `<<` are
# called on a string literal.
# bad
module Bar
  # ...
end

# good
# frozen_string_literal: true

module Bar
  # ...
end

Example: EnforcedStyle: never

# The `never` will enforce that the frozen string literal comment does
# not exist in a file.
# bad
# frozen_string_literal: true

module Baz
  # ...
end

# good
module Baz
  # ...
end

This cop looks for uses of Perl-style regexp match backreferences like $1, $2, etc.

Example:

# bad
puts $1

# good
puts Regexp.last_match(1)