znamenica/dneslov

This cop checks for redundant uses of self.

The usage of self is only needed when:

• Sending a message to same object with zero arguments in presence of a method name clash with an argument or a local variable.

• Calling an attribute writer to prevent an local variable assignment.

Note, with using explicit self you can only send messages with public or protected scope, you cannot send private messages this way.

Note we allow uses of self with operators because it would be awkward otherwise.

Example:

# bad
def foo(bar)
  self.baz
end

# good
def foo(bar)
  self.bar  # Resolves name clash with the argument.
end

def foo
  bar = 1
  self.bar  # Resolves name clash with the local variable.
end

def foo
  %w[x y z].select do |bar|
    self.bar == bar  # Resolves name clash with argument of the block.
  end
end

This cop checks whether comments have a leading space after the # denoting the start of the comment. The leading space is not required for some RDoc special syntax, like #++, #--, #:nodoc, =begin- and =end comments, "shebang" directives, or rackup options.

Example:

# bad
#Some comment

# good
# Some comment

This cop checks for missing top-level documentation of classes and modules. Classes with no body are exempt from the check and so are namespace modules - modules that have nothing in their bodies except classes, other modules, or constant definitions.

The documentation requirement is annulled if the class or module has a "#:nodoc:" comment next to it. Likewise, "#:nodoc: all" does the same for all its children.

Example:

# bad
class Person
  # ...
end

# good
# Description/Explanation of Person class
class Person
  # ...
end

This cop checks that the closing brace in an array literal is either on the same line as the last array element, or a new line.

When using the symmetrical (default) style:

If an array's opening brace is on the same line as the first element of the array, then the closing brace should be on the same line as the last element of the array.

If an array's opening brace is on the line above the first element of the array, then the closing brace should be on the line below the last element of the array.

When using the new_line style:

The closing brace of a multi-line array literal must be on the line after the last element of the array.

When using the same_line style:

The closing brace of a multi-line array literal must be on the same line as the last element of the array.

Example: EnforcedStyle: symmetrical (default)

# bad
  [ :a,
    :b
  ]

  # bad
  [
    :a,
    :b ]

  # good
  [ :a,
    :b ]

  # good
  [
    :a,
    :b
  ]

Example: EnforcedStyle: new_line

# bad
  [
    :a,
    :b ]

  # bad
  [ :a,
    :b ]

  # good
  [ :a,
    :b
  ]

  # good
  [
    :a,
    :b
  ]

Example: EnforcedStyle: same_line

# bad
  [ :a,
    :b
  ]

  # bad
  [
    :a,
    :b
  ]

  # good
  [
    :a,
    :b ]

  # good
  [ :a,
    :b ]

Check for uses of braces or do/end around single line or multi-line blocks.

Example: EnforcedStyle: linecountbased (default)

# bad - single line block
items.each do |item| item / 5 end

# good - single line block
items.each { |item| item / 5 }

# bad - multi-line block
things.map { |thing|
  something = thing.some_method
  process(something)
}

# good - multi-line block
things.map do |thing|
  something = thing.some_method
  process(something)
end

Example: EnforcedStyle: semantic

# Prefer `do...end` over `{...}` for procedural blocks.

# return value is used/assigned
# bad
foo = map do |x|
  x
end
puts (map do |x|
  x
end)

# return value is not used out of scope
# good
map do |x|
  x
end

# Prefer `{...}` over `do...end` for functional blocks.

# return value is not used out of scope
# bad
each { |x|
  x
}

# return value is used/assigned
# good
foo = map { |x|
  x
}
map { |x|
  x
}.inspect

Example: EnforcedStyle: bracesforchaining

# bad
words.each do |word|
  word.flip.flop
end.join("-")

# good
words.each { |word|
  word.flip.flop
}.join("-")

This cop checks the style of children definitions at classes and modules. Basically there are two different styles:

Example: EnforcedStyle: nested (default)

# good
# have each child on its own line
class Foo
  class Bar
  end
end

Example: EnforcedStyle: compact

# good
# combine definitions as much as possible
class Foo::Bar
end

The compact style is only forced for classes/modules with one child.

This cop enforces the consistent usage of %-literal delimiters.

Specify the 'default' key to set all preferred delimiters at once. You can continue to specify individual preferred delimiters to override the default.

Example:

# Style/PercentLiteralDelimiters:
#   PreferredDelimiters:
#     default: '[]'
#     '%i':    '()'

# good
%w[alpha beta] + %i(gamma delta)

# bad
%W(alpha #{beta})

# bad
%I(alpha beta)

This cop enforces the consistent usage of %-literal delimiters.

Specify the 'default' key to set all preferred delimiters at once. You can continue to specify individual preferred delimiters to override the default.

Example:

# Style/PercentLiteralDelimiters:
#   PreferredDelimiters:
#     default: '[]'
#     '%i':    '()'

# good
%w[alpha beta] + %i(gamma delta)

# bad
%W(alpha #{beta})

# bad
%I(alpha beta)

This cop checks for missing top-level documentation of classes and modules. Classes with no body are exempt from the check and so are namespace modules - modules that have nothing in their bodies except classes, other modules, or constant definitions.

The documentation requirement is annulled if the class or module has a "#:nodoc:" comment next to it. Likewise, "#:nodoc: all" does the same for all its children.

Example:

# bad
class Person
  # ...
end

# good
# Description/Explanation of Person class
class Person
  # ...
end

Check for parentheses around stabby lambda arguments. There are two different styles. Defaults to require_parentheses.

Example: EnforcedStyle: require_parentheses (default)

# bad
->a,b,c { a + b + c }

# good
->(a,b,c) { a + b + c}

Example: EnforcedStyle: requirenoparentheses

# bad
->(a,b,c) { a + b + c }

# good
->a,b,c { a + b + c}

Checks if uses of quotes match the configured preference.

Example: EnforcedStyle: single_quotes (default)

# bad
"No special symbols"
"No string interpolation"
"Just text"

# good
'No special symbols'
'No string interpolation'
'Just text'
"Wait! What's #{this}!"

Example: EnforcedStyle: double_quotes

# bad
'Just some text'
'No special chars or interpolation'

# good
"Just some text"
"No special chars or interpolation"
"Every string in #{project} uses double_quotes"

Checks for semicolon (;) not followed by some kind of space.

Example:

# bad
x = 1;y = 2

# good
x = 1; y = 2

This cop checks for missing top-level documentation of classes and modules. Classes with no body are exempt from the check and so are namespace modules - modules that have nothing in their bodies except classes, other modules, or constant definitions.

The documentation requirement is annulled if the class or module has a "#:nodoc:" comment next to it. Likewise, "#:nodoc: all" does the same for all its children.

Example:

# bad
class Person
  # ...
end

# good
# Description/Explanation of Person class
class Person
  # ...
end

This cop enforces the consistent usage of %-literal delimiters.

Specify the 'default' key to set all preferred delimiters at once. You can continue to specify individual preferred delimiters to override the default.

Example:

# Style/PercentLiteralDelimiters:
#   PreferredDelimiters:
#     default: '[]'
#     '%i':    '()'

# good
%w[alpha beta] + %i(gamma delta)

# bad
%W(alpha #{beta})

# bad
%I(alpha beta)

This cop checks the style of children definitions at classes and modules. Basically there are two different styles:

Example: EnforcedStyle: nested (default)

# good
# have each child on its own line
class Foo
  class Bar
  end
end

Example: EnforcedStyle: compact

# good
# combine definitions as much as possible
class Foo::Bar
end

The compact style is only forced for classes/modules with one child.

This cop (by default) checks for uses of the lambda literal syntax for single line lambdas, and the method call syntax for multiline lambdas. It is configurable to enforce one of the styles for both single line and multiline lambdas as well.

Example: EnforcedStyle: linecountdependent (default)

# bad
f = lambda { |x| x }
f = ->(x) do
      x
    end

# good
f = ->(x) { x }
f = lambda do |x|
      x
    end

Example: EnforcedStyle: lambda

# bad
f = ->(x) { x }
f = ->(x) do
      x
    end

# good
f = lambda { |x| x }
f = lambda do |x|
      x
    end

Example: EnforcedStyle: literal

# bad
f = lambda { |x| x }
f = lambda do |x|
      x
    end

# good
f = ->(x) { x }
f = ->(x) do
      x
    end

Check for parentheses around stabby lambda arguments. There are two different styles. Defaults to require_parentheses.

Example: EnforcedStyle: require_parentheses (default)

# bad
->a,b,c { a + b + c }

# good
->(a,b,c) { a + b + c}

Example: EnforcedStyle: requirenoparentheses

# bad
->(a,b,c) { a + b + c }

# good
->a,b,c { a + b + c}

Checks for semicolon (;) preceded by space.

Example:

# bad
x = 1 ; y = 2

# good
x = 1; y = 2

This cop enforces consistent use of Object#is_a? or Object#kind_of?.

Example: EnforcedStyle: is_a? (default)

# bad
var.kind_of?(Date)
var.kind_of?(Integer)

# good
var.is_a?(Date)
var.is_a?(Integer)

Example: EnforcedStyle: kind_of?

# bad
var.is_a?(Time)
var.is_a?(String)

# good
var.kind_of?(Time)
var.kind_of?(String)