thoughtbot/paperclip

This cop checks for the presence of parentheses around ternary conditions. It is configurable to enforce inclusion or omission of parentheses using EnforcedStyle. Omission is only enforced when removing the parentheses won't cause a different behavior.

Example: EnforcedStyle: requirenoparentheses (default)

# bad
foo = (bar?) ? a : b
foo = (bar.baz?) ? a : b
foo = (bar && baz) ? a : b

# good
foo = bar? ? a : b
foo = bar.baz? ? a : b
foo = bar && baz ? a : b

Example: EnforcedStyle: require_parentheses

# bad
foo = bar? ? a : b
foo = bar.baz? ? a : b
foo = bar && baz ? a : b

# good
foo = (bar?) ? a : b
foo = (bar.baz?) ? a : b
foo = (bar && baz) ? a : b

Example: EnforcedStyle: requireparentheseswhen_complex

# bad
foo = (bar?) ? a : b
foo = (bar.baz?) ? a : b
foo = bar && baz ? a : b

# good
foo = bar? ? a : b
foo = bar.baz? ? a : b
foo = (bar && baz) ? a : b

This cops checks if empty lines around the bodies of modules match the configuration.

Example: EnforcedStyle: empty_lines

# good

module Foo

  def bar
    # ...
  end

end

Example: EnforcedStyle: emptylinesexcept_namespace

# good

module Foo
  module Bar

    # ...

  end
end

Example: EnforcedStyle: emptylinesspecial

# good
module Foo

  def bar; end

end

Example: EnforcedStyle: noemptylines (default)

# good

module Foo
  def bar
    # ...
  end
end

This cop checks for every useless assignment to local variable in every scope. The basic idea for this cop was from the warning of ruby -cw:

assigned but unused variable - foo

Currently this cop has advanced logic that detects unreferenced reassignments and properly handles varied cases such as branch, loop, rescue, ensure, etc.

Example:

# bad

def some_method
  some_var = 1
  do_something
end

Example:

# good

def some_method
  some_var = 1
  do_something(some_var)
end

This cop checks hash literal syntax.

It can enforce either the use of the class hash rocket syntax or the use of the newer Ruby 1.9 syntax (when applicable).

A separate offense is registered for each problematic pair.

The supported styles are:

• ruby19 - forces use of the 1.9 syntax (e.g. {a: 1}) when hashes have all symbols for keys
• hash_rockets - forces use of hash rockets for all hashes
• nomixedkeys - simply checks for hashes with mixed syntaxes
• ruby19nomixed_keys - forces use of ruby 1.9 syntax and forbids mixed syntax hashes

Example: EnforcedStyle: ruby19 (default)

# bad
{:a => 2}
{b: 1, :c => 2}

# good
{a: 2, b: 1}
{:c => 2, 'd' => 2} # acceptable since 'd' isn't a symbol
{d: 1, 'e' => 2} # technically not forbidden

Example: EnforcedStyle: hash_rockets

# bad
{a: 1, b: 2}
{c: 1, 'd' => 5}

# good
{:a => 1, :b => 2}

Example: EnforcedStyle: nomixedkeys

# bad
{:a => 1, b: 2}
{c: 1, 'd' => 2}

# good
{:a => 1, :b => 2}
{c: 1, d: 2}

Example: EnforcedStyle: ruby19nomixed_keys

# bad
{:a => 1, :b => 2}
{c: 2, 'd' => 3} # should just use hash rockets

# good
{a: 1, b: 2}
{:c => 3, 'd' => 4}

This cop checks hash literal syntax.

It can enforce either the use of the class hash rocket syntax or the use of the newer Ruby 1.9 syntax (when applicable).

A separate offense is registered for each problematic pair.

The supported styles are:

• ruby19 - forces use of the 1.9 syntax (e.g. {a: 1}) when hashes have all symbols for keys
• hash_rockets - forces use of hash rockets for all hashes
• nomixedkeys - simply checks for hashes with mixed syntaxes
• ruby19nomixed_keys - forces use of ruby 1.9 syntax and forbids mixed syntax hashes

Example: EnforcedStyle: ruby19 (default)

# bad
{:a => 2}
{b: 1, :c => 2}

# good
{a: 2, b: 1}
{:c => 2, 'd' => 2} # acceptable since 'd' isn't a symbol
{d: 1, 'e' => 2} # technically not forbidden

Example: EnforcedStyle: hash_rockets

# bad
{a: 1, b: 2}
{c: 1, 'd' => 5}

# good
{:a => 1, :b => 2}

Example: EnforcedStyle: nomixedkeys

# bad
{:a => 1, b: 2}
{c: 1, 'd' => 2}

# good
{:a => 1, :b => 2}
{c: 1, d: 2}

Example: EnforcedStyle: ruby19nomixed_keys

# bad
{:a => 1, :b => 2}
{c: 2, 'd' => 3} # should just use hash rockets

# good
{a: 1, b: 2}
{:c => 3, 'd' => 4}

This cop checks for the formatting of empty method definitions. By default it enforces empty method definitions to go on a single line (compact style), but it can be configured to enforce the end to go on its own line (expanded style).

Note: A method definition is not considered empty if it contains comments.

Example: EnforcedStyle: compact (default)

# bad
def foo(bar)
end

def self.foo(bar)
end

# good
def foo(bar); end

def foo(bar)
  # baz
end

def self.foo(bar); end

Example: EnforcedStyle: expanded

# bad
def foo(bar); end

def self.foo(bar); end

# good
def foo(bar)
end

def self.foo(bar)
end

This cop checks for octal, hex, binary and decimal literals using uppercase prefixes and corrects them to lowercase prefix or no prefix (in case of decimals). eg. for octal use 0o instead of 0 or 0O.

Can be configured to use 0 only for octal literals using EnforcedOctalStyle => zero_only

This cops checks for parentheses around the arguments in method definitions. Both instance and class/singleton methods are checked.

Example: EnforcedStyle: require_parentheses (default)

# The `require_parentheses` style requires method definitions
# to always use parentheses

# bad
def bar num1, num2
  num1 + num2
end

def foo descriptive_var_name,
        another_descriptive_var_name,
        last_descriptive_var_name
  do_something
end

# good
def bar(num1, num2)
  num1 + num2
end

def foo(descriptive_var_name,
        another_descriptive_var_name,
        last_descriptive_var_name)
  do_something
end

Example: EnforcedStyle: requirenoparentheses

# The `require_no_parentheses` style requires method definitions
# to never use parentheses

# bad
def bar(num1, num2)
  num1 + num2
end

def foo(descriptive_var_name,
        another_descriptive_var_name,
        last_descriptive_var_name)
  do_something
end

# good
def bar num1, num2
  num1 + num2
end

def foo descriptive_var_name,
        another_descriptive_var_name,
        last_descriptive_var_name
  do_something
end

Example: EnforcedStyle: requirenoparenthesesexceptmultiline

# The `require_no_parentheses_except_multiline` style prefers no
# parantheses when method definition arguments fit on single line,
# but prefers parantheses when arguments span multiple lines.

# bad
def bar(num1, num2)
  num1 + num2
end

def foo descriptive_var_name,
        another_descriptive_var_name,
        last_descriptive_var_name
  do_something
end

# good
def bar num1, num2
  num1 + num2
end

def foo(descriptive_var_name,
        another_descriptive_var_name,
        last_descriptive_var_name)
  do_something
end

This cop checks hash literal syntax.

It can enforce either the use of the class hash rocket syntax or the use of the newer Ruby 1.9 syntax (when applicable).

A separate offense is registered for each problematic pair.

The supported styles are:

• ruby19 - forces use of the 1.9 syntax (e.g. {a: 1}) when hashes have all symbols for keys
• hash_rockets - forces use of hash rockets for all hashes
• nomixedkeys - simply checks for hashes with mixed syntaxes
• ruby19nomixed_keys - forces use of ruby 1.9 syntax and forbids mixed syntax hashes

Example: EnforcedStyle: ruby19 (default)

# bad
{:a => 2}
{b: 1, :c => 2}

# good
{a: 2, b: 1}
{:c => 2, 'd' => 2} # acceptable since 'd' isn't a symbol
{d: 1, 'e' => 2} # technically not forbidden

Example: EnforcedStyle: hash_rockets

# bad
{a: 1, b: 2}
{c: 1, 'd' => 5}

# good
{:a => 1, :b => 2}

Example: EnforcedStyle: nomixedkeys

# bad
{:a => 1, b: 2}
{c: 1, 'd' => 2}

# good
{:a => 1, :b => 2}
{c: 1, d: 2}

Example: EnforcedStyle: ruby19nomixed_keys

# bad
{:a => 1, :b => 2}
{c: 2, 'd' => 3} # should just use hash rockets

# good
{a: 1, b: 2}
{:c => 3, 'd' => 4}

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 uses of if/unless modifiers with multiple-lines bodies.

Example:

# bad
{
  result: 'this should not happen'
} unless cond

# good
{ result: 'ok' } if cond

This cop checks for the use of YAML class methods which have potential security issues leading to remote code execution when loading from an untrusted source.

Example:

# bad
YAML.load("--- foo")

# good
YAML.safe_load("--- foo")
YAML.dump("foo")

Checks that brackets used for array literals have or don't have surrounding space depending on configuration.

Example: EnforcedStyle: space

# The `space` style enforces that array literals have
# surrounding space.

# bad
array = [a, b, c, d]

# good
array = [ a, b, c, d ]

Example: EnforcedStyle: no_space

# The `no_space` style enforces that array literals have
# no surrounding space.

# bad
array = [ a, b, c, d ]

# good
array = [a, b, c, d]

Example: EnforcedStyle: compact

# The `compact` style normally requires a space inside
# array brackets, with the exception that successive left
# or right brackets are collapsed together in nested arrays.

# bad
array = [ a, [ b, c ] ]

# good
array = [ a, [ b, c ]]