Class: Reek::Smells::DataClump

Inherits:
SmellDetector show all
Defined in:
lib/reek/smells/data_clump.rb

Overview

A Data Clump occurs when the same two or three items frequently appear together in classes and parameter lists, or when a group of instance variable names start or end with similar substrings.

The recurrence of the items often means there is duplicate code spread around to handle them. There may be an abstraction missing from the code, making the system harder to understand.

Currently Reek looks for a group of two or more parameters with the same names that are expected by three or more methods of a class.

Constant Summary collapse

MAX_COPIES_KEY =

The name of the config field that sets the maximum allowed copies of any clump.

'max_copies'
DEFAULT_MAX_COPIES = 
2
MIN_CLUMP_SIZE_KEY = 
'min_clump_size'
DEFAULT_MIN_CLUMP_SIZE = 
2

Constants inherited from SmellDetector

SmellDetector::DEFAULT_EXCLUDE_SET, SmellDetector::EXCLUDE_KEY

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from SmellDetector

class_name, #configure, #configure_with, #copy, create, #enabled?, #examine, #exception?, #found, #has_smell?, listen, #listen_to, #num_smells, #report_on, #smell_name, #smelly?, #supersede_with, #value

Constructor Details

#initialize(config = DataClump.default_config) ⇒ DataClump

Returns a new instance of DataClump.



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# File 'lib/reek/smells/data_clump.rb', line 42

def initialize(config = DataClump.default_config)
  super(config)
end

Class Method Details

.contexts ⇒ Object

:nodoc:



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# File 'lib/reek/smells/data_clump.rb', line 22

def self.contexts      # :nodoc:
  [:class]
end

.default_config ⇒ Object 



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# File 'lib/reek/smells/data_clump.rb', line 35

def self.default_config
  super.adopt(
    MAX_COPIES_KEY => DEFAULT_MAX_COPIES,
    MIN_CLUMP_SIZE_KEY => DEFAULT_MIN_CLUMP_SIZE
  )
end

.print_clump(clump) ⇒ Object 



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# File 'lib/reek/smells/data_clump.rb', line 58

def self.print_clump(clump)
  "[#{clump.map {|name| name.to_s}.join(', ')}]"
end

Instance Method Details

#examine_context(klass) ⇒ Object

Checks the given ClassContext for multiple identical conditional tests. Remembers any smells found.



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# File 'lib/reek/smells/data_clump.rb', line 50

def examine_context(klass)
  max_copies = value(MAX_COPIES_KEY, klass, DEFAULT_MAX_COPIES)
  min_clump_size = value(MIN_CLUMP_SIZE_KEY, klass, DEFAULT_MIN_CLUMP_SIZE)
  MethodGroup.new(klass, min_clump_size, max_copies).clumps.each do |clump, occurs|
    found(klass, "takes parameters #{DataClump.print_clump(clump)} to #{occurs} methods")
  end
end