Class: Cuprum::RSpec::BeAResultMatcher

Parent Namespace

Cuprum::RSpec

Defined In

lib/cuprum/rspec/be_a_result_matcher.rb

Table Of Contents

• Overview
  • Examples
• Constructor
• Instance Attributes
  • expected_class
• Instance Methods
  • description
  • does_not_match?
  • failure_message
  • failure_message_when_negated
  • initialize
  • matches?
  • with_error
  • with_status
  • with_value

Overview

Asserts the actual object is a result object with the specified properties.

If initialized with a class, the matcher will assert that the actual object is an instance of that class. This can be useful for asserting that the result is an instance of a result subclass. If no class is given, the matcher asserts that the result is an object responding to #to_cuprum_result.

The matcher also defines fluent methods for asserting on the result’s properties:

• The #with_value method asserts that the result has the specified value. Also aliased as #and_value.
• The #with_error method asserts that the result has the specified error. Also aliased as #and_error.
• The #with_status method asserts that the result has the specified status. Also aliased as #and_status.

Generally speaking, you should use the #be_a_result, #be_a_passing_result, and #be_a_failing_result macros, rather than instantiating a BeAResultMatcher directly.

Examples

Matching Any Result

# Or use expect().to be_a_result
matcher = Cuprum::RSpec::BeAResultMatcher.new

matcher.matches?(nil)                #=> false
matcher.matches?(Cuprum::Result.new) #=> true

Matching A Result Status

# Or use expect().to be_a_passing_result
matcher = Cuprum::RSpec::BeAResultMatcher.new.with_status(:success)

matcher.matches?(Cuprum::Result.new(status: :failure)) #=> false
matcher.matches?(Cuprum::Result.new(status: :success)) #=> false

Matching A Result Value

matcher = Cuprum::RSpec::BeAResultMatcher.new.with_value({ ok: true })

matcher.matches?(Cuprum::Result.new(value: { ok: false })) #=> false
matcher.matches?(Cuprum::Result.new(value: { ok: true }))  #=> true

Matching A Result Error

error   = Cuprum::Error.new(message: 'Something went wrong')
matcher = Cuprum::RSpec::BeAResultMatcher.new.with_error(error)

other_error = Cuprum::Error.new(message: 'Oh no')
matcher.matches?(Cuprum::Result.new(error: other_error) #=> false
matcher.matches?(Cuprum::Result.new(error: error)       #=> true

Matching A Result Class

matcher = Cuprum::RSpec::BeAResultMatcher.new(CustomResult)

matcher.matches?(Cuprum::Result.new) #=> false
matcher.matches?(CustomResult.new)   #=> true

Matching Multiple Properties

matcher =
  Cuprum::RSpec::BeAResultMatcher
  .with_status(:failure)
  .and_value({ ok: false })
  .and_error(Cuprum::Error.new(message: 'Something went wrong'))

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Constructor

#initialize(expected_class = nil) => BeAResultMatcher

Parameters

• expected_class (Class) — the expected class of result. Defaults to Cuprum::Result.

Returns

• (BeAResultMatcher) — a new instance of BeAResultMatcher

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Instance Attributes

#expected_class => Class (readonly)

Returns

• (Class) — the expected class of result.

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Instance Methods

#description => String

Returns

• (String) — a short description of the matcher and expected properties.

#does_not_match?(actual) => Boolean

Checks that the given actual object is not a Cuprum result.

Parameters

• actual (Object) — the actual object to match.

Returns

• (Boolean) — false if the actual object is a result; otherwise true.

Raises

• (ArgumentError)

#failure_message => String

Returns

• (String) — a summary message describing a failed expectation.

#failure_message_when_negated => String

Returns

• (String) — a summary message describing a failed negated expectation.

#matches?(actual) => Boolean

Checks that the given actual object is a Cuprum result or compatible object and has the specified properties.

Parameters

• actual (Object) — The actual object to match.

Returns

• (Boolean) — true if the actual object is a result with the expected properties; otherwise false.

#with_error(error) => BeAResultMatcher

Also known as: and_error

Sets an error expectation on the matcher. Calls to #matches? will fail unless the actual object has the specified error.

Parameters

• error (Cuprum::Error, Object) — The expected error.

Returns

• (BeAResultMatcher) — the updated matcher.

#with_status(status) => BeAResultMatcher

Also known as: and_status

Sets a status expectation on the matcher. Calls to #matches? will fail unless the actual object has the specified status.

Parameters

• status (Symbol) — The expected status.

Returns

• (BeAResultMatcher) — the updated matcher.

#with_value(value) => BeAResultMatcher

Also known as: and_value

Sets a value expectation on the matcher. Calls to #matches? will fail unless the actual object has the specified value.

Parameters

• value (Object) — The expected value.

Returns

• (BeAResultMatcher) — the updated matcher.

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