In Rails I can use the test keyword for my tests which I find very attractive and a bettter choice to Rspec's verbosity.
Example:
class TestMyClass < ActionController::TestCase
test 'one equals one' do
assert 1 == 1
end
end
At the moment I am creating a gem and I want to follow the same way for my tests - by using the test method. I tried inheriting from Minitest and UnitTest and the latter seems to work. However I was under the impression that Rails uses Minitest. So does Minitest actually provide a test directive?
This works:
class TestMyClass < Test::Unit::TestCase
test 'one equals one' do
assert 1 == 1
end
end
This gives me "wrong number of arguments for test":
class TestMyClass < Minitest:Test
test 'one equals one' do
assert 1 == 1
end
end
No, Minitest runs ordinary methods with names started from 'test_'.
Method test from ActionController::TestCase is provided by Rails and works as a simple wrap for 'test_*' methods. It converts this
test 'truish' do
assert true
end
to this
def test_truish
assert true
end
Also it checks if the body of the test was defined, if it wasn't, it will show an error message.
I'm just starting a small project to emulate a Carnival's ticket sales booth and one of the guidelines was to test that a user can enter the number of tickets. The program runs in the console and I eventually (hopefully) figured it out how to implement this test thanks to #Stefan's answer on this question.
The problem is that now, when I run the test file, minitest says:
0 runs, 0 assertions, 0 failures, 0 errors, 0 skips
I get the same result when I try to run the test by name using ruby path/to/test/file.rb --name method-name. I'm not sure if this is because my code is still faulty of if it's because I've set up minitest incorrectly. I've tried to look up similar problems on SO but most questions seem to involve using minitest with rails and I just have a plain ruby project.
Here's my test file:
gem 'minitest', '>= 5.0.0'
require 'minitest/spec'
require 'minitest/autorun'
require_relative 'carnival'
class CarnivalTest < MiniTest::Test
def sample
assert_equal(1, 1)
end
def user_can_enter_number_of_tickets
with_stdin do |user|
user.puts "2"
assert_equal(Carnival.new.get_value, "2")
end
end
def with_stdin
stdin = $stdin # global var to remember $stdin
$stdin, write = IO.pipe # assign 'read end' of pipe to $stdin
yield write # pass 'write end' to block
ensure
write.close # close pipe
$stdin = stdin # restore $stdin
end
end
In a file called carnival.rb in the same folder as my test file I have
Class Carnival
def get_value
gets.chomp
end
end
If anyone can help figure out why the test is not running I'd be grateful!
By convention, tests in Minitest are public instance methods that start with test_, so the original test has no actual test methods. You need to update your test class so that the methods with assertions follow the convention as:
class CarnivalTest < Minitest::Test
def test_sample
assert_equal(1, 1)
end
def test_user_can_enter_number_of_tickets
with_stdin do |user|
user.puts "2"
assert_equal(Carnival.new.get_value, "2")
end
end
# snip...
end
Yeah always start all your tests with test_ so it knows that you want to that function/method
class CarnivalTest < MiniTest::Test
def test_sample
assert_equal(1, 1)
end
def test_user_can_enter_number_of_tickets
with_stdin do |user|
user.puts "2"
assert_equal(Carnival.new.get_value, "2")
end
end
and that should work for you
I have a question regaring Mocha expectations running with the Ruby Test::Unit framework.
My purpose is to verify the methods called when I call a wrapping method.
This test always seem to pass, I don't understand why...
I am expecting an error stating that the method clean has only be called once (with can be verified in the Expectation object).
Why is the following Unit Test not raising an error when I run the following test:
require 'test/unit'
require 'mocha'
require 'mocha/test_unit'
class DoMe
def stop_and_clean
clean
stop
end
def clean
true
end
def stop
true
end
end
class DoMeTest < Test::Unit::TestCase
def test_stop_and_clean
d = DoMe.new
d.expects(:clean).times(5)
assert(d.stop_and_clean)
end
end
It seems to me that expects(:clean).times(5) will not be satisfied, but running the test shows no error. Do I need to make an assertion on the Expectation object ?
exp = d.expects(:clean).times(5)
[...]
assert(that exp is invoked only once)
I am new to minitest and still new to ruby and really tired of trying to google this question without result. I would be really grateful for help:
What is the exact syntax of assert_output in ruby minitest?
All I find on github or elsewhere seems to use parentheses. Yet, I get an error message when I don't use a block with assert_output, which makes sense as the definition of this method contains a yield statement.
But I cannot make it work, whatever I try.
testclass.rb
class TestClass
def output
puts 'hey'
end
end
test_test.rb
require 'minitest/spec'
require 'minitest/autorun'
require_relative 'testclass'
class TestTestClass < MiniTest::Unit::TestCase
def setup
#test = TestClass.new
end
def output_produces_output
assert_output( stdout = 'hey' ) { #test.output}
end
end
What I get is:
Finished tests in 0.000000s, NaN tests/s, NaN assertions
0 tests, 0 assertions, 0 failures, 0 errors, 0 skips
What am I doing wrong?
It must be something totally obvious, but I cannot figure it out.
Thanks for your help.
In order for your test method to run, the method name needs to start with test_. Also, the way assert_output works is that the block will write to stdout/stderr, and the arguments will be checked if they match stdout/stderr. The easiest way to check this IMO is to pass in a regexp. So this is how I would write that test:
class TestTestClass < MiniTest::Unit::TestCase
def setup
#test = TestClass.new
end
def test_output_produces_output
assert_output(/hey/) { #test.output}
end
end
Is there an alternative to RSpec's before(:suite) and after(:suite) in MiniTest?
I suspect that a custom test runner is in order, however I cannot imagine it is not a common requirement, so somebody has probably implemented in. :-)
There are setup() and teardown() methods available. The documentation also lists before() and after() as being available.
Edit: Are you looking to run something before each test or before or after the whole suite is finished?
As noted above in Caley's answer and comments, MiniTest::Unit contains the function after_tests. There is no before_tests or equivalent, but any code in your minitest_helper.rb file should be run before the test suite, so that will do the office of such a function.
Caveat: Still relatively new at Ruby, and very new at Minitest, so if I'm wrong, please correct me! :-)
To get this to work with the current version of Minitest (5.0.6) you need to require 'minitest' and use Minitest.after_run { ... }.
warn "MiniTest::Unit.after_tests is now Minitest.after_run. ..."
https://github.com/seattlerb/minitest/blob/master/lib/minitest.rb
https://github.com/seattlerb/minitest/blob/master/lib/minitest/unit.rb
To run code before each test, use before. You're operating here in the context of an instance, possibly of a class generated implicitly by describe, so instance variables set in before are accessible in each test (e.g. inside an it block).
To run code before all tests, simply wrap the tests in a class, a subclass of MiniTest::Spec or whatever; now, before the tests themselves, you can create a class or module, set class variables, call a class method, etc., and all of that will be available in all tests.
Example:
require "minitest/autorun"
class MySpec < MiniTest::Spec
class MyClass
end
def self.prepare
puts "once"
##prepared = "prepared"
##count = 0
end
prepare
before do
puts "before each test"
#local_count = (##count += 1)
end
describe "whatever" do
it "first" do
p MyClass
p ##prepared
p #local_count
end
it "second" do
p MyClass
p ##prepared
p #local_count
end
end
end
Here's the output, along with my comments in braces explaining what each line of the output proves:
once [this code, a class method, runs once before all tests]
Run options: --seed 29618 [now the tests are about to run]
# Running tests:
before each test [the before block runs before each test]
MySpec::MyClass [the class we created earlier is visible in each test]
"prepared" [the class variable we set earlier is visible in each test]
1 [the instance variable from the before block is visible in each test]
before each test [the before block runs before each test]
MySpec::MyClass [the class we created earlier is visible in each test]
"prepared" [the class variable we set earlier is visible in each test]
2 [the instance variable from the before block is visible each test]
(Note that I do not mean this output to imply any guarantee about the order in which tests will run.)
Another approach is to use the existing before but wrap code to run only once in a class variable flag. Example:
class MySpec < MiniTest::Spec
##flag = nil
before do
unless ##flag
# do stuff here that is to be done only once
##flag = true
end
# do stuff here that is to be done every time
end
# ... tests go here
end
One simple way to do this is to write a guarded class method, and then call that in a begin.
A Minitest::Spec example:
describe "my stuff" do
def self.run_setup_code
if #before_flag.nil?
puts "Running the setup code"
#before_flag = true
end
end
before do
self.class.run_setup_code
end
it "will only run the setup code once" do
assert_equal 1, 1
end
it "really only ran it once" do
assert_equal 1,1
end
end
...to get
Run options: --seed 11380
# Running:
Running the setup code
..
Finished in 0.001334s, 1499.2504 runs/s, 1499.2504 assertions/s.
2 runs, 2 assertions, 0 failures, 0 errors, 0 skips
You can just place the code outside of the class.
This is what I do to have a banner.
require 'selenium-webdriver'
require 'minitest/test'
require 'minitest/autorun'
class InstanceTest < Minitest::Test
def setup
url = ARGV.first
#url = self.validate_instance(url)
#driver = Selenium::WebDriver.for :firefox
end
Nice thing about minitest is its flexibility. I've been using a custom MiniTest Runner with a +before_suite+ callback. Something like in this example - Ruby Minitest: Suite- or Class- level setup?
And then tell minitest to use the custom runner
MiniTest::Unit.runner = MiniTestSuite::Unit.new
You can also add an after test callback by updating your test_helper.rb (or spec_helper.rb) like this
# test_helper.rb
class MyTest < Minitest::Unit
after_tests do
# ... after test code
end
end