Class: Matchi::Change::To

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

Overview

*Change to* matcher.

Instance Method Summary collapse

Constructor Details

#initialize(expected, &state) ⇒ To

Initialize the matcher with an object and a block.

Examples:

require "matchi/change/to"

object = "foo"

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

Parameters:

  • expected (#object_id) —

    An expected new value.

  • state (Proc) —

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

Raises:

  • (::ArgumentError) 


19
20
21
22
23
24
 
# File 'lib/matchi/change/to.rb', line 19

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

  @expected = expected
  @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/to"

object = "foo"

matcher = Matchi::Change::To.new("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) 


41
42
43
44
45
46
47
48
 
# File 'lib/matchi/change/to.rb', line 41

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

  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



53
54
55
 
# File 'lib/matchi/change/to.rb', line 53

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