cequel/cequel

Checks for simple usages of parallel assignment. This will only complain when the number of variables being assigned matched the number of assigning variables.

Example:

# bad
a, b, c = 1, 2, 3
a, b, c = [1, 2, 3]

# good
one, two = *foo
a, b = foo()
a, b = b, a

a = 1
b = 2
c = 3

Checks that block braces have or don't have a space before the opening brace depending on configuration.

Example:

# bad
foo.map{ |a|
  a.bar.to_s
}

# good
foo.map { |a|
  a.bar.to_s
}

Checks that block braces have or don't have surrounding space inside them on configuration. For blocks taking parameters, it checks that the left brace has or doesn't have trailing space depending on configuration.

Example: EnforcedStyle: space (default)

# The `space` style enforces that block braces have
# surrounding space.

# bad
some_array.each {puts e}

# good
some_array.each { puts e }

Example: EnforcedStyle: no_space

# The `no_space` style enforces that block braces don't
# have surrounding space.

# bad
some_array.each { puts e }

# good
some_array.each {puts e}

Example: EnforcedStyleForEmptyBraces: no_space (default)

# The `no_space` EnforcedStyleForEmptyBraces style enforces that
# block braces don't have a space in between when empty.

# bad
some_array.each {   }
some_array.each {  }
some_array.each { }

# good
some_array.each {}

Example: EnforcedStyleForEmptyBraces: space

# The `space` EnforcedStyleForEmptyBraces style enforces that
# block braces have at least a spece in between when empty.

# bad
some_array.each {}

# good
some_array.each { }
some_array.each {  }
some_array.each {   }

Example: SpaceBeforeBlockParameters: true (default)

# The SpaceBeforeBlockParameters style set to `true` enforces that
# there is a space between `{` and `|`. Overrides `EnforcedStyle`
# if there is a conflict.

# bad
[1, 2, 3].each {|n| n * 2 }

# good
[1, 2, 3].each { |n| n * 2 }

Example: SpaceBeforeBlockParameters: true

# The SpaceBeforeBlockParameters style set to `false` enforces that
# there is no space between `{` and `|`. Overrides `EnforcedStyle`
# if there is a conflict.

# bad
[1, 2, 3].each { |n| n * 2 }

# good
[1, 2, 3].each {|n| n * 2 }

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 the multiline do end blocks have a newline after the start of the block. Additionally, it checks whether the block arguments, if any, are on the same line as the start of the block.

Example:

# bad
blah do |i| foo(i)
  bar(i)
end

# bad
blah do
  |i| foo(i)
  bar(i)
end

# good
blah do |i|
  foo(i)
  bar(i)
end

# bad
blah { |i| foo(i)
  bar(i)
}

# good
blah { |i|
  foo(i)
  bar(i)
}

This cop checks for uses of the case equality operator(===).

Example:

# bad
Array === something
(1..100) === 7
/something/ === some_string

# good
something.is_a?(Array)
(1..100).include?(7)
some_string =~ /something/

Checks that block braces have or don't have a space before the opening brace depending on configuration.

Example:

# bad
foo.map{ |a|
  a.bar.to_s
}

# good
foo.map { |a|
  a.bar.to_s
}

Checks that block braces have or don't have surrounding space inside them on configuration. For blocks taking parameters, it checks that the left brace has or doesn't have trailing space depending on configuration.

Example: EnforcedStyle: space (default)

# The `space` style enforces that block braces have
# surrounding space.

# bad
some_array.each {puts e}

# good
some_array.each { puts e }

Example: EnforcedStyle: no_space

# The `no_space` style enforces that block braces don't
# have surrounding space.

# bad
some_array.each { puts e }

# good
some_array.each {puts e}

Example: EnforcedStyleForEmptyBraces: no_space (default)

# The `no_space` EnforcedStyleForEmptyBraces style enforces that
# block braces don't have a space in between when empty.

# bad
some_array.each {   }
some_array.each {  }
some_array.each { }

# good
some_array.each {}

Example: EnforcedStyleForEmptyBraces: space

# The `space` EnforcedStyleForEmptyBraces style enforces that
# block braces have at least a spece in between when empty.

# bad
some_array.each {}

# good
some_array.each { }
some_array.each {  }
some_array.each {   }

Example: SpaceBeforeBlockParameters: true (default)

# The SpaceBeforeBlockParameters style set to `true` enforces that
# there is a space between `{` and `|`. Overrides `EnforcedStyle`
# if there is a conflict.

# bad
[1, 2, 3].each {|n| n * 2 }

# good
[1, 2, 3].each { |n| n * 2 }

Example: SpaceBeforeBlockParameters: true

# The SpaceBeforeBlockParameters style set to `false` enforces that
# there is no space between `{` and `|`. Overrides `EnforcedStyle`
# if there is a conflict.

# bad
[1, 2, 3].each { |n| n * 2 }

# good
[1, 2, 3].each {|n| n * 2 }

This cop checks the args passed to fail and raise. For exploded style (default), it recommends passing the exception class and message to raise, rather than construct an instance of the error. It will still allow passing just a message, or the construction of an error with more than one argument.

The exploded style works identically, but with the addition that it will also suggest constructing error objects when the exception is passed multiple arguments.

Example: EnforcedStyle: exploded (default)

# bad
raise StandardError.new("message")

# good
raise StandardError, "message"
fail "message"
raise MyCustomError.new(arg1, arg2, arg3)
raise MyKwArgError.new(key1: val1, key2: val2)

Example: EnforcedStyle: compact

# bad
raise StandardError, "message"
raise RuntimeError, arg1, arg2, arg3

# good
raise StandardError.new("message")
raise MyCustomError.new(arg1, arg2, arg3)
fail "message"

Checks for a newline after the final magic comment.

Example:

# good
# frozen_string_literal: true

# Some documentation for Person
class Person
  # Some code
end

# bad
# frozen_string_literal: true
# Some documentation for Person
class Person
  # Some code
end

Checks for a newline after the final magic comment.

Example:

# good
# frozen_string_literal: true

# Some documentation for Person
class Person
  # Some code
end

# bad
# frozen_string_literal: true
# Some documentation for Person
class Person
  # Some code
end

This cops checks for uses of Proc.new where Kernel#proc would be more appropriate.

Example:

# bad
p = Proc.new { |n| puts n }

# good
p = proc { |n| puts n }

This cop checks the indentation of the method name part in method calls that span more than one line.

Example: EnforcedStyle: aligned

# bad
while myvariable
.b
  # do something
end

# good
while myvariable
      .b
  # do something
end

# good
Thing.a
     .b
     .c

Example: EnforcedStyle: indented

# good
while myvariable
  .b

  # do something
end

Example: EnforcedStyle: indentedrelativeto_receiver

# good
while myvariable
        .a
        .b

  # do something
end

# good
myvariable = Thing
               .a
               .b
               .c

This cops checks for two or more consecutive blank lines.

Example:

# bad - It has two empty lines.
some_method
# one empty line
# two empty lines
some_method

# good
some_method
# one empty line
some_method

Checks for a newline after the final magic comment.

Example:

# good
# frozen_string_literal: true

# Some documentation for Person
class Person
  # Some code
end

# bad
# frozen_string_literal: true
# Some documentation for Person
class Person
  # Some code
end

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