Codeminer42/cm42-central

This cop checks for usage of comparison operators (==, >, <) to test numbers as zero, positive, or negative. These can be replaced by their respective predicate methods. The cop can also be configured to do the reverse.

The cop disregards nonzero? as it its value is truthy or falsey, but not true and false, and thus not always interchangeable with != 0.

Example:

# EnforcedStyle: predicate (default)

# bad

foo == 0
0 > foo
bar.baz > 0

# good

foo.zero?
foo.negative?
bar.baz.positive?

Example:

# EnforcedStyle: comparison

# bad

foo.zero?
foo.negative?
bar.baz.positive?

# good

foo == 0
0 > foo
bar.baz > 0

This cop makes sure that predicates are named properly.

Example:

# bad
def is_even?(value) ...

# good
def even?(value)

# bad
def has_value? ...

# good
def value? ...

This cop looks for use of the same name as outer local variables for block arguments or block local variables. This is a mimic of the warning "shadowing outer local variable - foo" from ruby -cw.

Example:

# bad

def some_method
  foo = 1

  2.times do |foo| # shadowing outer `foo`
    do_something(foo)
  end
end

Example:

# good

def some_method
  foo = 1

  2.times do |bar|
    do_something(bar)
  end
end

This cop checks for chaining of a block after another block that spans multiple lines.

Example:

Thread.list.find_all do |t|
  t.alive?
end.map do |t|
  t.object_id
end