Class: Matchi::Change::From::To

Inherits:
Object
  • Object
show all
Defined in:
lib/matchi/change/from/to.rb

Overview

*Change from to* matcher.

Instance Method Summary collapse

Constructor Details

#initialize(expected_init, expected_new_value, &state) ⇒ To

Initialize the matcher with two objects and a block.

Examples:

require "matchi/change/from/to"

object = "foo"

Matchi::Change::From::To.new("foo", "FOO") { object.to_s }

Parameters:

  • expected_init (#object_id) —

    An expected initial value.

  • expected_new_value (#object_id) —

    An expected new value.

  • state (Proc) —

    A block of code to execute to get the state of the object.

Raises:

  • (::ArgumentError) 


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# File 'lib/matchi/change/from/to.rb', line 21

def initialize(expected_init, expected_new_value, &state)
  raise ::ArgumentError, "a block must be provided" unless block_given?

  @expected_init  = expected_init
  @expected       = expected_new_value
  @state          = state
end

Instance Method Details

#match? ⇒ Boolean

Boolean comparison on the expected change by comparing the value before and after the code execution.

Examples:

require "matchi/change/from/to"

object = "foo"

matcher = Matchi::Change::From::To.new("foo", "FOO") { object.to_s }
matcher.match? { object.upcase! } # => true

Yield Returns:

  • (#object_id) —

    The block of code to execute.

Returns:

  • (Boolean) —

    Comparison between the value before and after the code execution.

Raises:

  • (::ArgumentError) 


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# File 'lib/matchi/change/from/to.rb', line 44

def match?
  raise ::ArgumentError, "a block must be provided" unless block_given?

  value_before = @state.call
  return false unless @expected_init == value_before

  yield
  value_after = @state.call

  @expected == value_after
end

#to_s ⇒ String

Returns a string representing the matcher.

Returns:

  • (String) —

    a human-readable description of the matcher



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# File 'lib/matchi/change/from/to.rb', line 59

def to_s
  "change from #{@expected_init.inspect} to #{@expected.inspect}"
end