thoughtbot/paperclip

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"

This cop checks for uses of rescue in its modifier form.

Example:

# bad
some_method rescue handle_error

# good
begin
  some_method
rescue
  handle_error
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 for multi-line ternary op expressions.

Example:

# bad
a = cond ?
  b : c
a = cond ? b :
    c
a = cond ?
    b :
    c

# good
a = cond ? b : c
a =
  if cond
    b
  else
    c
  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 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 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

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 that quotes inside the string interpolation match the configured preference.

Example: EnforcedStyle: single_quotes (default)

# bad
result = "Tests #{success ? "PASS" : "FAIL"}"

# good
result = "Tests #{success ? 'PASS' : 'FAIL'}"

Example: EnforcedStyle: double_quotes

# bad
result = "Tests #{success ? 'PASS' : 'FAIL'}"

# good
result = "Tests #{success ? "PASS" : "FAIL"}"

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 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")

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

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 ]]

Checks for spaces inside ordinary round parentheses.

Example:

# bad
f( 3)
g = (a + 3 )

# good
f(3)
g = (a + 3)

Use a consistent style for named format string tokens.

Note: unannotated style cop only works for strings which are passed as arguments to those methods: sprintf, format, %. The reason is that unannotated format is very similar to encoded URLs or Date/Time formatting strings.

Example: EnforcedStyle: annotated (default)

# bad
format('%{greeting}', greeting: 'Hello')
format('%s', 'Hello')

# good
format('%<greeting>s', greeting: 'Hello')</greeting>

Example: EnforcedStyle: template

# bad
format('%<greeting>s', greeting: 'Hello')
format('%s', 'Hello')

# good
format('%{greeting}', greeting: 'Hello')</greeting>

Example: EnforcedStyle: unannotated

# bad
format('%<greeting>s', greeting: 'Hello')
format('%{greeting}', 'Hello')

# good
format('%s', 'Hello')</greeting>

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 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