Class: RSpec::Matchers::AliasedMatcher Private

Inherits:
MatcherDelegator
  • Object
show all
Defined in:
lib/rspec/matchers/aliased_matcher.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Decorator that wraps a matcher and overrides description using the provided block in order to support an alias of a matcher. This is intended for use when composing matchers, so that you can use an expression like include( a_value_within(0.1).of(3) ) rather than include( be_within(0.1).of(3) ), and have the corresponding description read naturally.

Instance Method Summary collapse

Methods included from Composable

#===, #and, #description_of, #or, should_enumerate?, surface_descriptions_in, unreadable_io?, #values_match?

Constructor Details

#initialize(base_matcher, description_block) ⇒ AliasedMatcher

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of AliasedMatcher.

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# File 'lib/rspec/matchers/aliased_matcher.rb', line 13
def initialize(base_matcher, description_block)
  @description_block = description_block
  super(base_matcher)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Forward messages on to the wrapped matcher. Since many matchers provide a fluent interface (e.g. a_value_within(0.1).of(3)), we need to wrap the returned value if it responds to description, so that our override can be applied when it is eventually used.

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# File 'lib/rspec/matchers/aliased_matcher.rb', line 24
def method_missing(*)
  return_val = super
  return return_val unless RSpec::Matchers.is_a_matcher?(return_val)
  self.class.new(return_val, @description_block)
end

Instance Method Details

#description ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Provides the description of the aliased matcher. Aliased matchers are designed to behave identically to the original matcher except for the description and failure messages. The description is different to reflect the aliased name.

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# File 'lib/rspec/matchers/aliased_matcher.rb', line 36
def description
  @description_block.call(super)
end

#failure_message ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Provides the failure_message of the aliased matcher. Aliased matchers are designed to behave identically to the original matcher except for the description and failure messages. The failure_message is different to reflect the aliased name.

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# File 'lib/rspec/matchers/aliased_matcher.rb', line 46
def failure_message
  @description_block.call(super)
end

#failure_message_when_negated ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Provides the failure_message_when_negated of the aliased matcher. Aliased matchers are designed to behave identically to the original matcher except for the description and failure messages. The failure_message_when_negated is different to reflect the aliased name.

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# File 'lib/rspec/matchers/aliased_matcher.rb', line 56
def failure_message_when_negated
  @description_block.call(super)
end