ece517-p3/expertiza

This cop checks for identical lines at the beginning or end of each branch of a conditional statement.

Example:

# bad
if condition
  do_x
  do_z
else
  do_y
  do_z
end

# good
if condition
  do_x
else
  do_y
end
do_z

# bad
if condition
  do_z
  do_x
else
  do_z
  do_y
end

# good
do_z
if condition
  do_x
else
  do_y
end

# bad
case foo
when 1
  do_x
when 2
  do_x
else
  do_x
end

# good
case foo
when 1
  do_x
  do_y
when 2
  # nothing
else
  do_x
  do_z
end

Use a guard clause instead of wrapping the code inside a conditional expression

Example:

# bad
def test
  if something
    work
  end
end

# good
def test
  return unless something
  work
end

# also good
def test
  work if something
end

# bad
if something
  raise 'exception'
else
  ok
end

# good
raise 'exception' if something
ok

This cop checks for the use of Time methods without zone.

Built on top of Ruby on Rails style guide (https://github.com/bbatsov/rails-style-guide#time) and the article http://danilenko.org/2012/7/6/rails_timezones/ .

Two styles are supported for this cop. When EnforcedStyle is 'strict' then only use of Time.zone is allowed.

When EnforcedStyle is 'flexible' then it's also allowed to use Time.intimezone.

Example:

# always offense
Time.now
Time.parse('2015-03-02 19:05:37')

# no offense
Time.zone.now
Time.zone.parse('2015-03-02 19:05:37')

# no offense only if style is 'flexible'
Time.current
DateTime.strptime(str, "%Y-%m-%d %H:%M %Z").in_time_zone
Time.at(timestamp).in_time_zone

This cop checks for identical lines at the beginning or end of each branch of a conditional statement.

Example:

# bad
if condition
  do_x
  do_z
else
  do_y
  do_z
end

# good
if condition
  do_x
else
  do_y
end
do_z

# bad
if condition
  do_z
  do_x
else
  do_z
  do_y
end

# good
do_z
if condition
  do_x
else
  do_y
end

# bad
case foo
when 1
  do_x
when 2
  do_x
else
  do_x
end

# good
case foo
when 1
  do_x
  do_y
when 2
  # nothing
else
  do_x
  do_z
end

This cop checks for the use of Time methods without zone.

Built on top of Ruby on Rails style guide (https://github.com/bbatsov/rails-style-guide#time) and the article http://danilenko.org/2012/7/6/rails_timezones/ .

Two styles are supported for this cop. When EnforcedStyle is 'strict' then only use of Time.zone is allowed.

When EnforcedStyle is 'flexible' then it's also allowed to use Time.intimezone.

Example:

# always offense
Time.now
Time.parse('2015-03-02 19:05:37')

# no offense
Time.zone.now
Time.zone.parse('2015-03-02 19:05:37')

# no offense only if style is 'flexible'
Time.current
DateTime.strptime(str, "%Y-%m-%d %H:%M %Z").in_time_zone
Time.at(timestamp).in_time_zone

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

Use a guard clause instead of wrapping the code inside a conditional expression

Example:

# bad
def test
  if something
    work
  end
end

# good
def test
  return unless something
  work
end

# also good
def test
  work if something
end

# bad
if something
  raise 'exception'
else
  ok
end

# good
raise 'exception' if something
ok

This cop checks for identical lines at the beginning or end of each branch of a conditional statement.

Example:

# bad
if condition
  do_x
  do_z
else
  do_y
  do_z
end

# good
if condition
  do_x
else
  do_y
end
do_z

# bad
if condition
  do_z
  do_x
else
  do_z
  do_y
end

# good
do_z
if condition
  do_x
else
  do_y
end

# bad
case foo
when 1
  do_x
when 2
  do_x
else
  do_x
end

# good
case foo
when 1
  do_x
  do_y
when 2
  # nothing
else
  do_x
  do_z
end

Checks for colon (:) not followed by some kind of space. N.B. this cop does not handle spaces after a ternary operator, which are instead handled by Layout/SpaceAroundOperators.

Example:

# bad
def f(a:, b:2); {a:3}; end

# good
def f(a:, b: 2); {a: 3}; end

This cop checks whether the end keywords of method definitions are aligned properly.

Two modes are supported through the EnforcedStyleAlignWith configuration parameter. If it's set to start_of_line (which is the default), the end shall be aligned with the start of the line where the def keyword is. If it's set to def, the end shall be aligned with the def keyword.

Example: EnforcedStyleAlignWith: startofline (default)

# bad

private def foo
            end

# good

private def foo
end

Example: EnforcedStyleAlignWith: def

# bad

private def foo
            end

# good

private def foo
        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 for trailing comma in array and hash literals.

Example: EnforcedStyleForMultiline: consistent_comma

# bad
a = [1, 2,]

# good
a = [
  1, 2,
  3,
]

# good
a = [
  1,
  2,
]

Example: EnforcedStyleForMultiline: comma

# bad
a = [1, 2,]

# good
a = [
  1,
  2,
]

Example: EnforcedStyleForMultiline: no_comma (default)

# bad
a = [1, 2,]

# good
a = [
  1,
  2
]

This cop checks for identical lines at the beginning or end of each branch of a conditional statement.

Example:

# bad
if condition
  do_x
  do_z
else
  do_y
  do_z
end

# good
if condition
  do_x
else
  do_y
end
do_z

# bad
if condition
  do_z
  do_x
else
  do_z
  do_y
end

# good
do_z
if condition
  do_x
else
  do_y
end

# bad
case foo
when 1
  do_x
when 2
  do_x
else
  do_x
end

# good
case foo
when 1
  do_x
  do_y
when 2
  # nothing
else
  do_x
  do_z
end

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 cop checks for comments put on the same line as some keywords. These keywords are: begin, class, def, end, module.

Note that some comments (such as :nodoc: and rubocop:disable) are allowed.

Example:

# bad
if condition
  statement
end # end if

# bad
class X # comment
  statement
end

# bad
def x; end # comment

# good
if condition
  statement
end

# good
class X # :nodoc:
  y
end

This cop makes sure that all variables use the configured style, snake_case or camelCase, for their names.

Example: EnforcedStyle: snake_case (default)

# bad
fooBar = 1

# good
foo_bar = 1

Example: EnforcedStyle: camelCase

# bad
foo_bar = 1

# good
fooBar = 1

This cop looks for uses of the for keyword, or each method. The preferred alternative is set in the EnforcedStyle configuration parameter. An each call with a block on a single line is always allowed, however.

This cop makes sure that all variables use the configured style, snake_case or camelCase, for their names.

Example: EnforcedStyle: snake_case (default)

# bad
fooBar = 1

# good
foo_bar = 1

Example: EnforcedStyle: camelCase

# bad
foo_bar = 1

# good
fooBar = 1