Class: Minitest::Proptest::Gen::ValueGenerator

Inherits:
Object
  • Object
show all
Defined in:
lib/minitest/proptest/gen/value_generator.rb

Overview

Methods for value generation

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#entropy ⇒ Object

Returns the value of attribute entropy.



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 8

def entropy
  @entropy
end

#type_parameters=(value) ⇒ Object (writeonly)

Sets the attribute type_parameters

Parameters:

  • value —

    the value to set the attribute type_parameters to.



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 9

def type_parameters=(value)
  @type_parameters = value
end

Class Method Details

.bound_max ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 40

def self.bound_max
  1
end

.bound_min ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 44

def self.bound_min
  0
end

.empty(gen) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 53

def self.empty(gen)
  self.new(gen)
end

.with_append(bound_min, bound_max, &f) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 21

def self.with_append(bound_min, bound_max, &f)
  define_singleton_method(:bound_min) { bound_min }
  define_singleton_method(:bound_max) { bound_max }
  define_method(:append) do |other|
    @value = f.call(value, other.value)
    self
  end
  self
end

.with_empty(&f) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 31

def self.with_empty(&f)
  define_singleton_method(:empty) do |gen|
    temp = new(gen)
    temp.instance_variable_set(:@value, f.call)
    temp
  end
  self
end

.with_score_function(&f) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 16

def self.with_score_function(&f)
  define_method(:score_function, &f)
  self
end

.with_shrink_function(&f) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 11

def self.with_shrink_function(&f)
  define_method(:shrink_function, &f)
  self
end

Instance Method Details

#append(_other) ⇒ Object

append is not expected to be called unless overridden



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 49

def append(_other)
  self
end

#force(v) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 57

def force(v)
  temp = self.class.new(ArgumentError)
  temp.instance_variable_set(:@value, v)
  temp.type_parameters = @type_parameters
  temp
end

#generate_value ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 64

def generate_value
  gen = @generated.reduce(@generator) do |g, val|
    g.call(val)
    g
  end

  while gen.is_a?(Proc) || gen.is_a?(Method)
    gen = gen.call(*@type_parameters.map(&:value))
    gen = gen.value if gen.is_a?(ValueGenerator)
  end

  gen
end

#one_of(r) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 127

def one_of(r)
  r.to_a[sized(r.to_a.length - 1)]
end

#prefix_entropy_generation(vals) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 84

def prefix_entropy_generation(vals)
  @generated = vals + @generated
end

#score ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 88

def score
  value
  fs = @type_parameters.map { |x| x.method(:score_function) }
  score_function(*fs, value)
end

#score_function(v) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 94

def score_function(v)
  v.to_i.abs
end

#shrink_candidates ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 98

def shrink_candidates
  fs = @type_parameters.map { |x| x.method(:shrink_function) }
  os = score
  # Ensure that the end of the shrink attempt will contain the original
  # value.  This is necessary to guarantee that the shrink process
  # produces at least one failure for the purpose of capturing variable
  # assignment.
  candidates = shrink_function(*fs, value) + [value]
  candidates
    .map    { |c| [force(c).score, c] }
    .reject { |(s, _)| s > os }
    .sort   { |x, y| x.first <=> y.first }
    .uniq
end

#shrink_function(x) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 113

def shrink_function(x)
  [x.itself]
end

#shrink_parameter(x) ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 117

def shrink_parameter(x)
  @shrink_parameter.call(x)
end

#sized(n) ⇒ Object

Generator helpers



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 123

def sized(n)
  entropy.call(n + 1)
end

#value ⇒ Object 



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# File 'lib/minitest/proptest/gen/value_generator.rb', line 78

def value
  return false if @value == false

  @value ||= generate_value
end