class Shoulda::ActiveRecord::Matchers::HaveNamedScopeMatcher

def call_succeeds?
  scope
  true
rescue Exception => exception
  @missing_expectation = "#{@subject.class.name} " <<
    "to respond to #{@scope_call} " <<
    "but raised error: #{exception.inspect}"
  false
end

def description
  result = "have a named scope for #{@scope_call}"
  result << " finding #{@finding.inspect}" unless @finding.nil?
  result
end

def failure_message
  "Expected #{@missing_expectation}"
end

def finding(finding)
  @finding = finding
  self
end

def finds_correct_scope?
  return true if @finding.nil?
  if @finding == scope.proxy_options
    true
  else
    @missing_expectation = "#{@scope_call} to return results scoped to "
    @missing_expectation << "#{@finding.inspect} but was scoped to "
    @missing_expectation << scope.proxy_options.inspect
    false
  end
end

def in_context(context)
  @context = context
  self
end

def initialize(scope_call)
  @scope_call = scope_call.to_s
end

def matches?(subject)
  @subject = subject
  call_succeeds? && returns_scope? && finds_correct_scope?
end

def negative_failure_message
  "Didn't expect a named scope for #{@scope_call}"
end

def returns_scope?
  if ::ActiveRecord::NamedScope::Scope === scope
    true
  else
    @missing_expectation = "#{@scope_call} to return a scope"
    false
  end
end

def scope
  @scope ||= @context.instance_eval("#{@subject.class.name}.#{@scope_call}")
end