I have two classes:
1.Sale is a subclass of ActiveRecord; its job is to persist sales data to the database.
class Sale < ActiveRecord::Base
def self.total_for_duration(start_date, end_date)
self.count(conditions: {date: start_date..end_date})
end
#...
end
2.SalesReport is a standard Ruby class; its job is to produce and graph information about Sales.
class SalesReport
def initialize(start_date, end_date)
#start_date = start_date
#end_date = end_date
end
def sales_in_duration
Sale.total_for_duration(#start_date, #end_date)
end
#...
end
Because I want to use TDD and I want my tests to run really fast, I have written a spec for SalesReport that doesn't doesn't load Rails:
require_relative "../../app/models/sales_report.rb"
class Sale; end
# NOTE I have had to re-define Sale because I don't want to
# require `sale.rb` because it would then require ActiveRecord.
describe SalesReport do
describe "sales_in_duration" do
it "calls Sale.total_for_duration" do
Sale.should_receive(:total_for_duration)
SalesReport.new.sales_in_duration
end
end
end
This test works when I run bundle exec rspec spec/models/report_spec.rb.
However this test fails when I run bundle exec rake spec with the error superclass mismatch for class Sale (TypeError). I know the error is happening because Tap is defined by sale.rb and inline within the spec.
So my question is there a way to Stub (or Mock or Double) a class if that class isn't defined? This would allow me to remove the inline class Sale; end, which feels like a hack.
If not, how do I set up my tests such that they run correctly whether I run bundle exec rspec or bundle exec rake spec?
If not, is my approach to writing fast tests wrong?!
Finally, I don't want to use Spork. Thanks!
RSpec's recently added stub_const is specifically designed for cases like these:
describe SalesReport do
before { stub_const("Sale", Class.new) }
describe "sales_in_duration" do
it "calls Sale.total_for_duration" do
Sale.should_receive(:total_for_duration)
SalesReport.new.sales_in_duration
end
end
end
You may also want to use rspec-fire to use a test double in place of Sale that automatically checks all the mocked/stubbed methods exist on the real Sale class when running your tests with the real Sale class loaded (e.g. when you run your test suite):
require 'rspec/fire'
describe SalesReport do
include RSpec::Fire
describe "sales_in_duration" do
it "calls Sale.total_for_duration" do
fire_replaced_class_double("Sale")
Sale.should_receive(:total_for_duration)
SalesReport.new.sales_in_duration
end
end
end
If you rename total_for_duration on the real Sale class, rspec-fire will give you an error when you mock the method since it doesn't exist on the real class.
A simple way would be to check if "Sale" has already been defined
unless defined?(Sale)
class Sale; end
end
Sale need not be a class either in your test so:
unless defined?(Sale)
Sale = double('Sale')
end
Related
I often build little single-purpose Ruby scripts like this:
#!/usr/bin/env ruby
class Widget
def end_data
DATA.read
end
def render_data source_data
source_data.upcase
end
end
w = Widget.new
puts w.render_data(w.end_data)
__END__
data set to work on.
I'd like to include RSpec tests directly inside the file while I'm working on it. Something like this (which doesn't work but illustrates what I'm trying to do):
#!/usr/bin/env ruby
class Widget
def end_data
DATA.read
end
def render_data source_data
source_data.upcase
end
def self_test
# This doesn't work but shows what I'm trying to
# accomplish. The goal is to have RSpec run these type
# of test when self_test is called.
describe "Widget" do
it "should render data properly" do
#w = Widget.new
expect(#w.render_data('test string')).to eq 'TEST STRING'
end
end
end
end
w = Widget.new
w.self_test
__END__
data set to work on.
I understand this is not the normal way to work with RSpec and isn't appropriate in most cases. That said, there are times when it would be nice. So, I'd like to know, is it possible?
There are two things. First off rspec by default won't pollute the global namespace with methods like describe and so on. The second thing is that you need to tell rspec to run the specs after they've been declared.
If you change your self_test method to be
RSpec.describe "Widget" do
it "should render data properly" do
#w = Widget.new
expect(#w.render_data('test string')).to eq 'TEST STRING'
end
end
RSpec::Core::Runner.invoke
(having of course done require 'rspec' then that will run your specs).
The invoke methods exits the process after running the specs. If you don't want to do that, or need more control over where output goes etc. you might want to drop down to the run method which allows you to control these things.
I've extracted a single class from a Rails app into a gem. It's very, very simple, but of course I'd like to fully test it (I'm using rspec).
The class does some simple date-calculation. It's not dependent on Rails, but since it started out in a Rails app, and is still used there, it uses ActiveSupport's time zone-aware methods when it can. But, if ActiveSupport isn't available, it should use the std-lib Date methods.
Specifically, it only does this in one single place: Defaulting an optional argument to "today's date":
arg ||= if Date.respond_to?(:current)
Date.current # use ActiveSupport's time zone-aware mixin if possible
else
Date.today # stdlib fallback
end
Question is: How do I properly test this? If I require ActiveSupport in my spec_helper.rb, it'll obviously always use that. If I don't require it anywhere, it'll never use it. And if I require it for a single example group, rspec's random execution order makes the testing unpredictable, as I don't know when AS will be required.
I can require maybe it in a before(:all) in a nested group, as nested groups are (I believe) processed highest to deepest. But that seems terribly inelegant.
I could also split the specs into two files, and run them separately, but again, that seems unnecessary.
I could also disable rspec's random ordering, but that's sort of going against the grain. I'd rather have it as randomized as possible.
Any ideas?
Another solution is to mock the current and today methods, and use those for testing. Eg:
# you won't need these two lines, just there to make script work standalone
require 'rspec'
require 'rspec/mocks/standalone'
def test_method(arg = nil)
arg ||= if Date.respond_to?(:current)
Date.current # use ActiveSupport's time zone-aware mixin if possible
else
Date.today # stdlib fallback
end
arg
end
describe "test_method" do
let(:test_date) { Date.new(2001, 2, 3) }
it "returns arg unchanged if not nil" do
test_method(34).should == 34
end
context "without Date.current available" do
before(:all) do
Date.stub(:today) { test_date }
end
it "returns Date.today when arg isn't present" do
test_method.should == test_date
end
end
context "with Date.current available" do
before(:all) do
Date.stub(:current) { test_date }
end
it "returns Date.current when arg isn't present" do
test_method.should == test_date
end
end
end
Running with rspec test.rb results in the tests passing.
Also, the stubs are present only in each context, so it doesn't matter what order the specs are run in.
This is more than a little perverse, but it should work. Include ActiveSupport, and then:
context "without ActiveSupport's Date.current" do
before(:each) do
class Date
class << self
alias_method :current_backup, :current
undef_method :current
end
end
end
# your test
after(:each) do
class Date
class << self
alias_method :current, :current_backup
end
end
end
end
I can't really recommend this; I would prefer to split out this one spec and run it separately as you suggested.
I've got an interesting conundrum. I'm in the midst of developing a library to parse PSDs in Ruby. Also, a buddy is simultaneously working on a library to parse PSDs in JavaScript. We would like to share the same unit tests via a git submodule.
We've decided to use a simple JSON DSL to define each test. A single test might look like:
{
"_name": "Layer should render out",
"_file": "test/fixtures/layer_out.psd",
"_exports_to": "test/controls/layer_out_control.png"
}
So, now it's up to us to build the appropriate test harnesses to translate the JSON into the appropriate native unit tests. I've been using MiniTest to get myself up to speed, but I'm running into a few walls.
Here's what I've got so far. The test harness is named TargetPractice for the time being:
# run_target_practice.rb
require 'target_practice'
TargetPractice.new(:test) do |test|
test.pattern = "test/**/*.json"
end
and
# psd_test.rb
class PSDTest < MiniTest::Unit::TestCase
attr_accessor :data
def tests_against_data
# do some assertions
end
end
and
# target_practice.rb
class TargetPractice
attr_accessor :libs, :pattern
def initialize(sym)
#libs = []
#pattern = ""
yield self
run_tests
end
def run_tests
FileList[#pattern].to_a.each do |file|
test_data = JSON.parse(File.open(file).read)
test = PSDTest.new(test_data["_name"]) do |t|
t.data = test_data
end
end
end
end
Unfortunately, I'm having trouble getting a yield in the initialize to stick in my PSDTest class. Also, it appears that a test will run immediately on initialization.
I would like to dynamically create a few MiniTest::Unit::TestCase objects, set their appropriate data properties and then run the tests. Any pointers are appreciated!
I think you are overcomplicating things a bit here. What you need is a parameterized test, which is pretty trivial to implement using mintest/spec:
describe "PSD converter" do
def self.tests(pattern = 'test/**/*.json')
FileList[pattern].map{|file| JSON.parse(File.read(file))}
end
tests.each do |test|
it "satisfies test: " + test["_name"] do
# some assertions using test["_file"] and test["_exports_to"]
end
end
end
I know. This is discouraged. For reasons I won't get into, I need to run my tests in the order they are written. According to the documentation, if my test class (we'll call it TestClass) extends Minitest::Unit::TestCase, then I should be able to call the public method i_suck_and_my_tests_are_order_dependent! (Gee - do you think the guy who created Minitest had an opinion on that one?). Additionally, there is also the option of calling a method called test_order and specifying :alpha to override the default behavior of :random. Neither of these are working for me.
Here's an example:
class TestClass < Minitest::Unit::TestCase
#override random test run ordering
i_suck_and_my_tests_are_order_dependent!
def setup
...setup code
end
def teardown
...teardown code
end
def test_1
test_1 code....
assert(stuff to assert here, etc...)
puts 'test_1'
end
def test_2
test_2_code
assert(stuff to assert here, etc...)
puts 'test_2'
end
end
When I run this, I get:
undefined method `i_suck_and_my_tests_are_order_dependent!' for TestClass:Class (NoMethodError)
If I replace the i_suck method call with a method at the top a la:
def test_order
:alpha
end
My test runs, but I can tell from the puts for each method that things are still running in random order each time I run the tests.
Does anyone know what I'm doing wrong?
Thanks.
If you just add test_order: alpha to your test class, the tests will run in order:
class TestHomePage
def self.test_order
:alpha
end
def test_a
puts "a"
end
def test_b
puts "b"
end
end
Note that, as of minitest 5.10.1, the i_suck_and_my_tests_are_order_dependent! method/directive is completely nonfunctional in test suites using MiniTest::Spec syntax. The Minitest.test_order method is apparently not being called at all.
EDIT: This has been a known issue since Minitest 5.3.4: see seattlerb/minitest#514 for the blow-by-blow wailing and preening.
You and I aren't the ones who "suck". What's needed is a BDD specification tool for Ruby without the bloat of RSpec and without the frat-boy attitude and contempt for wider community practices of MiniTest. Does anyone have any pointers?
i_suck_and_my_tests_are_order_dependent! may be a later addition to minitest & not available as a Ruby core method. In that case, you'd want to force use of your gem version:
require 'rubygems'
gem 'minitest'
I think that the method *test_order* should be a class method and not a instance method like so:
# tests are order dependent
def self.test_order
:alpha
end
The best way to interfere in this chain may be to override a class method runnable_methods:
def self.runnable_methods
['run_first'] | super | ['run_last']
end
#Minitest version:
def self.runnable_methods
methods = methods_matching(/^test_/)
case self.test_order
when :random, :parallel then
max = methods.size
methods.sort.sort_by { rand max }
when :alpha, :sorted then
methods.sort
else
raise "Unknown test_order: #{self.test_order.inspect}"
end
end
You can reorder test any suitable way around. If you define your special ordered tests with
test 'some special ordered test' do
end
, don't forget to remove them from the results of super call.
In my example I need to be sure only in one particular test to run last, so I keep random order on whole suite and place 'run_last' at the end of it.
In my test app, which uses test::unit, I need to start by pulling a bunch of data from various sources. I'd like to only do this once - the data is only read, not written, and doesn't change between tests, and the loading (and error checking for the loading), takes some time.
There are values that I DO want reset every time, and those are easy enough, but what if I want persistant accessible values? What's the best way to do this?
I'm especially interested in solutions that would let my push those assignments to some module that can be included in all my tests, since they all need access to this data.
Why do you need it inside the test? You could define it gloabl:
gem 'test-unit'#, '>= 2.1.1' #startup
require 'test/unit'
GLOBAL_DATA = 11
class My_Tests < Test::Unit::TestCase
def test_1()
puts "Testing startup 1"
assert_equal(11, GLOBAL_DATA)
end
end
GLOBAL_DATA could be a (singleton)-class (respective an instance).
If you have only one testclass, you may use TestCase.startup:
gem 'test-unit'#, '>= 2.1.1' #startup
require 'test/unit'
class My_Tests < Test::Unit::TestCase
def self.startup
puts "Define global_data "
##global_data = 11
end
def test_1()
puts "Testing 1"
assert_equal(11, ##global_data = 11)
end
def test_2()
puts "Testing 2"
assert_equal(11, ##global_data = 11)
end
end
You can just put them at the top of the class. They will get executed, and then your tests will get executed.
You could do this in the setup method:
def setup
if !defined?(##initial_data)
# Whatever you need to do to get your initial data
##initial_data = foo
end
#other_data = bar
end