I'm writing a testing library that works on top of rspec. I have a custom dsl that looks like this:
rast Worker do
prepare do |day_type, dow|
allow(subject).to receive(:holiday?) { day_type == 'Holiday' }
allow(subject).to receive(:dow) { dow }
end
execute do
result subject.goto_work?
end
end
The two allow statements do not work because they are inside my custom DSL rast with the method prepare. How can I make it work?
Inside the execute method I invoke this prepare block like this:
def execute
prepare_block = #prepare_block
RSpec.describe "test" do
prepare_block&.call(*params)
...
I don't have the whole picture, but at a guess and off the top of my mind, you may fare better with something like
RSpec.describe "test" do
instance_eval(prepare_block, *params) if prepare_block
end
instance_eval will evaluate the block in the context of the receiver (so whatever self is inside the describe block).
If you just do prepare_block.call, it won't have access to any methods defined in the context where it happened to be called from, as you found out.
Good luck!
Related
I want to write an rspec test by mocking this method. Should I break this method up, as it doing multiple things?
require 'yaml'
require_relative 'checkerror'
class Operations
def initialize
#check
end
def result (result_log: File.new('result.txt', 'a+'))
if #check.errors.empty?
result_log.write("#{#check.checker.file_path} :: No offensenses detected\n")
#checker is instance of CheckError class
puts "#{#check.checker.file_path} :: No offensenses detected\n"
else
#check.errors.uniq.each do |err| puts "#{#check.checker.file_path} : #{err}\n"
result_log.write("#{#check.checker.file_path} : #{err}\n")
end
end
result_log.close
end
end
end
If #check.errors need to be stuubed with a value and check the execution block.
It's going to be awkward mocking the f object in your current implementation, due to this line:
f = File.new('result.txt', 'a+')
You'd need to write something weird in the rspec test, like:
allow(File).to receive(:new).with('result.txt', 'a+').and_return(mock_file)
So instead, I'd recommend using dependency injection to pass the file into the method. For example:
def check_result(results_log: File.new('result.txt', 'a+'))
if #errors.empty?
# ...
end
Now, your rspec test can look something like this:
let(:results_log) { Tempfile.new }
it "prints errors to log file" do
wharever_this_object_is_called.check_result(result_log: results_log)
expect(result_log.read).to eq("checker_file_path.txt :: No offences detected\n")
end
I have something like:
value = nil
if some_condition
value =my_object.do_stuff()
end
And in my test, I have the follwing:
MyObject.any_instance.should_receive(:do_stuff)
However, I'd like to just test that the method was called, and have it execute the original code. I'd like to NOT have to do it like:
MyObject.any_instance.should_receive(:do_stuff).and_return(:some_dummy_value)
Is there a way of doing that?
There is and_call_original method:
MyObject.any_instance.should_receive(:do_stuff).and_call_original
See https://github.com/rspec/rspec-mocks#delegating-to-the-original-implementation
I believe, that it's better to create object by FactoryGirl and than to test it. You can read how to make factories and so on.
Example:
FactoryGirl.define do
factory :my_object do
[*here is your attributes*]
end
end
So, after you created a factory, you should to create test where this method used and write this:
my_object = FactoryGirl.create(:my_object)
my_object.should_receive(:do_stuff)
Inside your code you will do that "do_stuff" with your "my_object" when u will run test.
Normally the before and after hooks are assumed to be "initializing" and "cleanup" code respectively. They are supposed to happen "outside of the tests themselves".
I find myself in a situation in which I want to use after as the last step of all the tests in a context. But since after is usually meant to be "cleanup", I am afraid that my tests won't be very explicit. Here's a sample:
describe "when removing" do
let!(:request) do
stub_request(:delete, "http://localhost:4567/containers/#{container.id}").
to_return(status: 200)
end
# returns an http response
subject { client.remove(container.id) }
it { should be }
it { should include('id' => container.id) }
after { expect(request).to have_been_made }
end
I would like to rename that last after to something more explicit, like invariant, to indicate that it is part of the test. I have tried doing this on my spec helper:
# spec_helper.rb
Rspec.configure do |c|
...
end
RSpec::Core::Hooks.class_eval do
alias_method :invariant, :after
end
requiring spec_helper does not seem to throw any errors, but when I run the tests replacing after with invariant I get "undefined method 'invariant' for #<Class:0x007f9872b46588> (NoMethodError)" when running the tests.
It seems there is no easy way to do this, just use before/after
In my code I have code similar to the following contrived example.
class Excel
def self.do_tasks
with_excel do |excel|
delete_old_exports
export_images(excel)
export_documents(excel)
end
end
def with_excel
excel = WIN32OLE.connect('Excel.Application')
begin
yield excel
ensure
excel.close()
end
end
end
Now, I want to write a test for the 'do_tasks' method, where I set up expectations for the method calls and see if those expectations are fulfilled.
I tried the following approach (with shoulda-context and test-unit). However,the expectations fail for the three last mocks (the mocks do not get called).
class ExcelTest < ActiveSupport::TestCase
should "call the expected methods" do
mock.proxy(Excel).with_excel
mock(Excel).delete_old_exports
mock(Excel).export_images.with_any_args
mock(Excel).export_documents.with_any_args
Excel.do_tasks
end
end
Any pointers on how to test this sort of code would be much appreciated!
An older question, but I've just been doing some work on some similar code with rr and thought I'd throw in an answer.
The following test will do what you asked (using RR and TestUnit):
describe Excel do
describe '.do_tasks' do
let(:excel_ole) { mock!.close.subject }
before do
stub(WIN32OLE).connect('Excel.Application') { excel_ole }
mock(Excel).delete_old_exports
mock(Excel).export_images(excel_ole)
mock(Excel).export_documents(excel_ole)
end
it 'calls the expected methods' do
Excel.do_tasks
assert_received(Excel) { |subject| subject.delete_old_exports }
end
end
end
It uses RR's "spy" doubles - see https://github.com/rr/rr#spies
However, in the case of the sample code you provided, the fact that the methods you want to test are inside a block is an implementation detail and shouldn't be implicitly tested (this can lead to brittle tests). The test above shows this, the with_excel method is not mocked (incidentally, this should be defined as self.with_excel for the code to work). The implementation could be refactored so that the WIN32OLE initialisation and teardown happens inline in the .do_tasks method and the test would still pass.
On another note, it may be a side effect of the contrived example, but in general it's a bad idea to test non-public methods. The methods delete_old_exports, export_images and export_documents look like they should perhaps be factored out to collaborators.
How can I do something like:
it { should have_constant(:FIXED_LIST) }
In my model (active record) I have FIXED_LIST = 'A String'
It's not a db attribute or a method and I haven't been able to use responds_to or has_attribute to test for it (they fail). What can I use the to check for it. - btw I have the shoulda-matchers installed.
Based on David Chelimsky's answer I've got this to work by slightly modifying his code.
In a file spec/support/utilities.rb (or some other in spec/support) you can put:
RSpec::Matchers.define :have_constant do |const|
match do |owner|
owner.const_defined?(const)
end
end
Note the use of "RSpec::Matchers.define" in stead of "matchers"
This allows to test for constants in your specs, like:
it "should have a fixed list constant" do
YourModel.should have_constant(:FIXED_LIST)
end
Note the use of "have_constant" in stead of "have_const"
It reads a little silly, but:
describe MyClass do
it { should be_const_defined(:VERSION) }
end
The reason is that Rspec has "magic" matchers for methods starting with be_ and have_. For example, it { should have_green_pants } would assert that the has_green_pants? method on the subject returns true.
In the same fashion, an example such as it { should be_happy } would assert that the happy? method on the subject returns true.
So, the example it { should be_const_defined(:VERSION) } asserts that const_defined?(:VERSION) returns true.
If you want to say have_constant you can define a custom matcher for it:
matcher :have_constant do |const|
match do |owner|
owner.const_defined?(const)
end
end
MyClass.should have_const(:CONST)
If you're trying to use the one-liner syntax, you'll need to make sure the subject is a class (not an instance) or check for it in the matcher:
matcher :have_constant do |const|
match do |owner|
(owner.is_a?(Class) ? owner : owner.class).const_defined?(const)
end
end
See http://rubydoc.info/gems/rspec-expectations/RSpec/Matchers for more info on custom matchers.
HTH,
David
Another option to simply make sure the constant is defined – not worrying about what it's defined with:
it 'has a WHATEVER constant' do
expect(SomeClass::WHATEVER).not_to be_nil
end
A warning to anyone trying to test that constants are defined: If your code references an undefined constant while defining a class, then your specs will crash before they get to your test.
This can lead you to believe that
expect { FOO }.to_not raise_error
is failing to catch the NameError, because you'll get a big stack trace, instead of a nice "expected not to raise error, but raised NameError."
Amidst the huge stack trace, it can be difficult to notice that your test is actually crashing on line 1: requre "spec/spec_helper" because your entire application is failing to load before it gets to your actual test.
This can happen if you have dynamically defined constants, such as is done by ActiveHash::Enum, and you then use them in the definition of another constant. Don't bother testing that they exist, every spec in your app will crash if one of them fails to be defined.
You could use
defined? YOUR_MODEL::FIXED_LIST
In RSpec 2, I was able to get this to work in one line as follows:
it { subject.class.should be_const_defined(:MY_CONST) }
That is, check against the class, instead of the instance.
In My model
class Role < ActiveRecord::Base
ROLE_ADMIN = "Administrador"
end
In My rspec
RSpec.describe Role, type: :model do
let(:fake_class) { Class.new }
describe "set constants" do
before { stub_const("#{described_class}", fake_class) }
it { expect(described_class::ROLE_ADMIN).to eq("Administrador") }
end
end
For ruby 2.1.5 and rspec 3.5.0 I am able to test that constant SEARCH_CHARS_TO_IGNORE is defined in the class DiffAlertsDatatable as follows:
expect(DiffAlertsDatatable.const_defined?(:SEARCH_CHARS_TO_IGNORE)).to eq(true)