receive_request.rb

require "rspec"
require "mustermann"

# Checks whether client condition has received given request
#
# @example
#   allow(client)
#     .to receive_request(:get, "example.com/users/:id/bills")
#     .and_return({ id: 1, price: 100, currency: "RUR" })
#
#   expect(client)
#     .to receive_request(:get, "example.com/users/:id/bills")
#     .exactly(1).times
#
#   client.path(:users, 1, :bills).get
#   # => { id: 1, price: 100, currency: "RUR" }
#
RSpec::Matchers.define :receive_request do |method, path = nil|
  # List of constraints for the request
  #
  # @return [Array<Proc>]
  #
  def constraints
    @constraints ||= check_arguments
  end

  # A constraint to check whether a request satisfies given method and path
  #
  # @return [Proc]
  #
  def check_arguments
    proc { |req| check_method[req] && check_path[req] }
  end

  # Checks whether a request satisfies path constraint
  #
  # @reurn [Boolean]
  #
  def check_path
    return proc { |_| true } unless path

    pattern = Mustermann.new(path, type: :rails)
    proc { |req| pattern == req[:path].to_s }
  end

  # Checks whether a request satisfies method constraint
  #
  # @return [Boolean]
  #
  def check_method
    return proc { |_| true } if method == :any
    proc { |req| req[:method] == method.to_s }
  end

  # The resulting receive matcher for the client's connection
  #
  # @return [RSpec::Mocks::Matchers::Receive]
  #
  def satisfy_condition
    @satisfy_condition ||= receive(:call).with(&constraints)
  end

  match do |client|
    expect(client.connection).to satisfy_condition
  end

  match_when_negated do |client|
    expect(client.connection).not_to satisfy_condition
  end

  chain :where do |&block|
    @constraints = proc { |req| constraints[req] && block[req] }
  end

  chain :and_call_original do
    @satisfy_condition = satisfy_condition.and_call_original
  end

  chain :and_wrap_original do |&block|
    @satisfy_condition = satisfy_condition.and_wrap_original(&block)
  end

  chain :and_raise do |*args|
    @satisfy_condition = satisfy_condition.and_raise(*args)
  end

  chain :and_return do |*args, &block|
    @satisfy_condition = satisfy_condition.and_return(*args, &block)
  end

  chain :and_throw do |*args|
    @satisfy_condition = satisfy_condition.and_throw(*args)
  end

  chain :and_yield do |*args|
    @satisfy_condition = satisfy_condition.and_yield(*args)
  end

  chain :at_least do |value|
    @satisfy_condition = satisfy_condition.at_least(value)
  end

  chain :at_most do |value|
    @satisfy_condition = satisfy_condition.at_most(value)
  end

  chain :exactly do |value|
    @satisfy_condition = satisfy_condition.exactly(value)
  end

  chain :never do
    @satisfy_condition = satisfy_condition.never
  end

  chain :once do
    @satisfy_condition = satisfy_condition.once
  end

  chain :ordered do
    @satisfy_condition = satisfy_condition.ordered
  end

  chain :thrice do
    @satisfy_condition = satisfy_condition.thrice
  end

  chain :times do
    @satisfy_condition = satisfy_condition.times
  end

  chain :time do
    @satisfy_condition = satisfy_condition.times
  end

  chain :twice do
    @satisfy_condition = satisfy_condition.twice
  end
end