Assignment Branch Condition size for fetch_result is too high. [25.06/15] Open
def fetch_result
raise "Invalid navigation link for #{nav_name}" unless link[:href]
options = {
type: nav_property.entity_type,
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This cop checks that the ABC size of methods is not higher than the configured maximum. The ABC size is based on assignments, branches (method calls), and conditions. See http://c2.com/cgi/wiki?AbcMetric
Method has too many lines. [20/10] Open
def fetch_result
raise "Invalid navigation link for #{nav_name}" unless link[:href]
options = {
type: nav_property.entity_type,
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This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.
Complex method FrOData::NavigationProperty::Proxy#fetch_result (27.7) Open
def fetch_result
raise "Invalid navigation link for #{nav_name}" unless link[:href]
options = {
type: nav_property.entity_type,
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Flog calculates the ABC score for methods. The ABC score is based on assignments, branches (method calls), and conditions.
You can read more about ABC metrics or the flog tool
FrOData::NavigationProperty::Proxy#fetch_result has approx 10 statements Open
def fetch_result
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A method with Too Many Statements
is any method that has a large number of lines.
Too Many Statements
warns about any method that has more than 5 statements. Reek's smell detector for Too Many Statements
counts +1 for every simple statement in a method and +1 for every statement within a control structure (if
, else
, case
, when
, for
, while
, until
, begin
, rescue
) but it doesn't count the control structure itself.
So the following method would score +6 in Reek's statement-counting algorithm:
def parse(arg, argv, &error)
if !(val = arg) and (argv.empty? or /\A-/ =~ (val = argv[0]))
return nil, block, nil # +1
end
opt = (val = parse_arg(val, &error))[1] # +2
val = conv_arg(*val) # +3
if opt and !arg
argv.shift # +4
else
val[0] = nil # +5
end
val # +6
end
(You might argue that the two assigments within the first @if@ should count as statements, and that perhaps the nested assignment should count as +2.)
Method fetch_result
has a Cognitive Complexity of 8 (exceeds 5 allowed). Consider refactoring. Open
def fetch_result
raise "Invalid navigation link for #{nav_name}" unless link[:href]
options = {
type: nav_property.entity_type,
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Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
FrOData::NavigationProperty::Proxy has no descriptive comment Open
class Proxy
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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
FrOData::NavigationProperty::Proxy#fetch_result calls 'link[:href]' 2 times Open
raise "Invalid navigation link for #{nav_name}" unless link[:href]
options = {
type: nav_property.entity_type,
namespace: namespace,
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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.
FrOData::NavigationProperty::Proxy#value performs a nil-check Open
if link.nil?
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A NilCheck
is a type check. Failures of NilCheck
violate the "tell, don't ask" principle.
Additionally, type checks often mask bigger problems in your source code like not using OOP and / or polymorphism when you should.
Example
Given
class Klass
def nil_checker(argument)
if argument.nil?
puts "argument isn't nil!"
end
end
end
Reek would emit the following warning:
test.rb -- 1 warning:
[3]:Klass#nil_checker performs a nil-check. (NilCheck)
Method value
has a Cognitive Complexity of 6 (exceeds 5 allowed). Consider refactoring. Open
def value
if link.nil?
if nav_property.nav_type == :collection
[]
else
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Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Redundant else
-clause. Open
else
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Checks for empty else-clauses, possibly including comments and/or an
explicit nil
depending on the EnforcedStyle.
Example: EnforcedStyle: empty
# warn only on empty else
# bad
if condition
statement
else
end
# good
if condition
statement
else
nil
end
# good
if condition
statement
else
statement
end
# good
if condition
statement
end
Example: EnforcedStyle: nil
# warn on else with nil in it
# bad
if condition
statement
else
nil
end
# good
if condition
statement
else
end
# good
if condition
statement
else
statement
end
# good
if condition
statement
end
Example: EnforcedStyle: both (default)
# warn on empty else and else with nil in it
# bad
if condition
statement
else
nil
end
# bad
if condition
statement
else
end
# good
if condition
statement
else
statement
end
# good
if condition
statement
end
Missing top-level class documentation comment. Open
class Proxy
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This cop checks for missing top-level documentation of classes and modules. Classes with no body are exempt from the check and so are namespace modules - modules that have nothing in their bodies except classes, other modules, or constant definitions.
The documentation requirement is annulled if the class or module has a "#:nodoc:" comment next to it. Likewise, "#:nodoc: all" does the same for all its children.
Example:
# bad
class Person
# ...
end
# good
# Description/Explanation of Person class
class Person
# ...
end
Avoid rescuing without specifying an error class. Open
rescue => ex
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This cop checks for rescuing StandardError
. There are two supported
styles implicit
and explicit
. This cop will not register an offense
if any error other than StandardError
is specified.
Example: EnforcedStyle: implicit
# `implicit` will enforce using `rescue` instead of
# `rescue StandardError`.
# bad
begin
foo
rescue StandardError
bar
end
# good
begin
foo
rescue
bar
end
# good
begin
foo
rescue OtherError
bar
end
# good
begin
foo
rescue StandardError, SecurityError
bar
end
Example: EnforcedStyle: explicit (default)
# `explicit` will enforce using `rescue StandardError`
# instead of `rescue`.
# bad
begin
foo
rescue
bar
end
# good
begin
foo
rescue StandardError
bar
end
# good
begin
foo
rescue OtherError
bar
end
# good
begin
foo
rescue StandardError, SecurityError
bar
end
Use attr_writer
to define trivial writer methods. Open
def value=(value)
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This cop looks for trivial reader/writer methods, that could have been created with the attr_* family of functions automatically.
Example:
# bad
def foo
@foo
end
def bar=(val)
@bar = val
end
def self.baz
@baz
end
# good
attr_reader :foo
attr_writer :bar
class << self
attr_reader :baz
end