Common has no descriptive comment Open
module Common
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Classes and modules are the units of reuse and release. It is therefore considered good practice to annotate every class and module with a brief comment outlining its responsibilities.
Example
Given
class Dummy
# Do things...
end
Reek would emit the following warning:
test.rb -- 1 warning:
[1]:Dummy has no descriptive comment (IrresponsibleModule)
Fixing this is simple - just an explaining comment:
# The Dummy class is responsible for ...
class Dummy
# Do things...
end
Common#set_theme calls 'prefs.theme' 2 times Open
if prefs && prefs.theme
@user_theme = prefs.theme.parameterize.underscore
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Duplication occurs when two fragments of code look nearly identical, or when two fragments of code have nearly identical effects at some conceptual level.
Reek implements a check for Duplicate Method Call.
Example
Here's a very much simplified and contrived example. The following method will report a warning:
def double_thing()
@other.thing + @other.thing
end
One quick approach to silence Reek would be to refactor the code thus:
def double_thing()
thing = @other.thing
thing + thing
end
A slightly different approach would be to replace all calls of double_thing
by calls to @other.double_thing
:
class Other
def double_thing()
thing + thing
end
end
The approach you take will depend on balancing other factors in your code.
HACK found Open
# HACK: This is something of a hack to use the correct operator for Pg
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Use safe navigation (&.
) instead of checking if an object exists before calling the method. Open
if prefs && prefs.theme
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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 (&.
).
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(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(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }
# good
foo&.bar
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo.nil? || foo.bar
!foo || foo.bar
# Methods that `nil` will `respond_to?` should not be converted to
# use safe navigation
foo.to_i if foo
Use the return of the conditional for variable assignment and comparison. Open
if ActiveRecord::Base.connection.adapter_name.downcase.to_sym == :postgresql
like = 'ILIKE'
else
like = 'LIKE'
end
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Use the return of the conditional for variable assignment and comparison. Open
if prefs && prefs.theme
@user_theme = prefs.theme.parameterize.underscore
else
@user_theme = SITE_CONFIG['default_theme'] || 'light_blue'
end
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Missing magic comment # frozen_string_literal: true
. Open
module Common
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This cop is designed to help upgrade to Ruby 3.0. It will add the
comment # frozen_string_literal: true
to the top of files to
enable frozen string literals. Frozen string literals may be default
in Ruby 3.0. The comment will be added below a shebang and encoding
comment. The frozen string literal comment is only valid in Ruby 2.3+.
Example: EnforcedStyle: when_needed (default)
# The `when_needed` style will add the frozen string literal comment
# to files only when the `TargetRubyVersion` is set to 2.3+.
# bad
module Foo
# ...
end
# good
# frozen_string_literal: true
module Foo
# ...
end
Example: EnforcedStyle: always
# The `always` style will always add the frozen string literal comment
# to a file, regardless of the Ruby version or if `freeze` or `<<` are
# called on a string literal.
# bad
module Bar
# ...
end
# good
# frozen_string_literal: true
module Bar
# ...
end
Example: EnforcedStyle: never
# The `never` will enforce that the frozen string literal comment does
# not exist in a file.
# bad
# frozen_string_literal: true
module Baz
# ...
end
# good
module Baz
# ...
end
Redundant return
detected. Open
return like
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This cop checks for redundant return
expressions.
Example:
def test
return something
end
def test
one
two
three
return something
end
It should be extended to handle methods whose body is if/else or a case expression with a default branch.