mena-devs/tilde

This cop looks for trailing blank lines and a final newline in the source code.

Example: EnforcedStyle: finalblankline

# `final_blank_line` looks for one blank line followed by a new line
# at the end of files.
 
# bad
class Foo; end
# EOF
 
# bad
class Foo; end # EOF
 
# good
class Foo; end
 
# EOF

Example: EnforcedStyle: final_newline (default)

# `final_newline` looks for one newline at the end of files.
 
# bad
class Foo; end
 
# EOF
 
# bad
class Foo; end # EOF
 
# good
class Foo; end
# EOF

This cop transforms usages of a method call safeguarded by a non nil check for the variable whose method is being called to safe navigation (&.). If there is a method chain, all of the methods in the chain need to be checked for safety, and all of the methods will need to be changed to use safe navigation. We have limited the cop to not register an offense for method chains that exceed 2 methods.

Configuration option: ConvertCodeThatCanStartToReturnNil The default for this is false. When configured to true, this will check for code in the format !foo.nil? && foo.bar. As it is written, the return of this code is limited to false and whatever the return of the method is. If this is converted to safe navigation, foo&.bar can start returning nil as well as what the method returns.

Example:

# bad
foo.bar if foo
foo.bar.baz if foo
foo.bar(param1, param2) if foo
foo.bar { |e| e.something } if foo
foo.bar(param) { |e| e.something } if foo
 
foo.bar if !foo.nil?
foo.bar unless !foo
foo.bar unless foo.nil?
 
foo && foo.bar
foo && foo.bar.baz
foo && foo.bar(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }
 
# good
foo&.bar
foo&.bar&.baz
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo && foo.bar.baz.qux # method chain with more than 2 methods
foo && foo.nil? # method that `nil` responds to
 
# Method calls that do not use `.`
foo && foo < bar
foo < bar if foo
 
# This could start returning `nil` as well as the return of the method
foo.nil? || foo.bar
!foo || foo.bar
 
# Methods that are used on assignment, arithmetic operation or
# comparison should not be converted to use safe navigation
foo.baz = bar if foo
foo.baz + bar if foo
foo.bar > 2 if foo