thoughtbot/paperclip

This cop checks for braces around the last parameter in a method call if the last parameter is a hash. It supports braces, no_braces and context_dependent styles.

Example: EnforcedStyle: braces

# The `braces` style enforces braces around all method
# parameters that are hashes.

# bad
some_method(x, y, a: 1, b: 2)

# good
some_method(x, y, {a: 1, b: 2})

Example: EnforcedStyle: no_braces (default)

# The `no_braces` style checks that the last parameter doesn't
# have braces around it.

# bad
some_method(x, y, {a: 1, b: 2})

# good
some_method(x, y, a: 1, b: 2)

Example: EnforcedStyle: context_dependent

# The `context_dependent` style checks that the last parameter
# doesn't have braces around it, but requires braces if the
# second to last parameter is also a hash literal.

# bad
some_method(x, y, {a: 1, b: 2})
some_method(x, y, {a: 1, b: 2}, a: 1, b: 2)

# good
some_method(x, y, a: 1, b: 2)
some_method(x, y, {a: 1, b: 2}, {a: 1, b: 2})

This cop checks for redundant begin blocks.

Currently it checks for code like this:

Example:

def redundant
  begin
    ala
    bala
  rescue StandardError => e
    something
  end
end

def preferred
  ala
  bala
rescue StandardError => e
  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}

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