Class: RSpec::SleepingKingStudios::Support::ValueSpy

Inherits:
Object
  • Object
show all
Defined in:
lib/rspec/sleeping_king_studios/support/value_spy.rb

Overview

Encapsulates the value of a method call or block, and captures a snapshot of the value at the time the spy is initialized.

Examples:

Observing a Method

user  = Person.new(name: 'Alan Bradley')
value = ValueSpy.new(user, :name)
value.initial_value #=> 'Alan Bradley'
value.current_value #=> 'Alan Bradley'

user.name = 'Ed Dillinger'
value.initial_value #=> 'Alan Bradley'
value.current_value #=> 'Ed Dillinger'

Observing a Block

value = ValueSpy.new { Person.where(virtual: false).count }
value.initial_value #=> 4
value.current_value #=> 4

Person.where(name: 'Kevin Flynn').enter_grid!
value.initial_value #=> 4
value.current_value #=> 3

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(receiver, method_name) ⇒ ValueSpy #initialize { ... } ⇒ ValueSpy

Returns a new instance of ValueSpy.

Overloads:

  • #initialize(receiver, method_name) ⇒ ValueSpy

    Parameters:

    • receiver (Object) —

      The object to watch.

    • method_name (Symbol, String) —

      The name of the method to watch.

  • #initialize { ... } ⇒ ValueSpy

    Yields:

    • The value to watch. The block will be called each time the value is requested, and the return value of the block will be given as the current value.



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# File 'lib/rspec/sleeping_king_studios/support/value_spy.rb', line 37

def initialize(receiver = nil, method_name = nil, &block)
  @observed_block = if block_given?
    block
  else
    @method_name = method_name

    -> { receiver.send(method_name) }
  end

  @receiver        = receiver
  @initial_hash    = current_value.hash
  @initial_inspect = current_value.inspect
  @initial_value   = current_value
end

Instance Attribute Details

#initial_hash ⇒ Integer (readonly)

Returns the hash of the watched value at the time the spy was initialized.

Returns:

  • (Integer) —

    the hash of the watched value at the time the spy was initialized.



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# File 'lib/rspec/sleeping_king_studios/support/value_spy.rb', line 54

def initial_hash
  @initial_hash
end

#initial_inspect ⇒ String (readonly)

Returns the string representation of the watched value at the time the spy was initialized.

Returns:

  • (String) —

    the string representation of the watched value at the time the spy was initialized



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# File 'lib/rspec/sleeping_king_studios/support/value_spy.rb', line 58

def initial_inspect
  @initial_inspect
end

#initial_value ⇒ Object (readonly)

Returns the watched value at the time the spy was initialized.

Returns:

  • (Object) —

    the watched value at the time the spy was initialized.



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# File 'lib/rspec/sleeping_king_studios/support/value_spy.rb', line 61

def initial_value
  @initial_value
end

Instance Method Details

#changed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rspec/sleeping_king_studios/support/value_spy.rb', line 63

def changed?
  initial_value != current_value || initial_hash != current_value.hash
end

#current_value ⇒ Object

Returns the watched value when #current_value is called.

Returns:

  • (Object) —

    the watched value when #current_value is called.



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# File 'lib/rspec/sleeping_king_studios/support/value_spy.rb', line 68

def current_value
  @observed_block.call
end

#description ⇒ String

Returns a human-readable representation of the watched method or block.

Returns:

  • (String) —

    a human-readable representation of the watched method or block.



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# File 'lib/rspec/sleeping_king_studios/support/value_spy.rb', line 74

def description
  return 'result' unless @method_name

  format_message
end