Seems like the internet doesn't have a definitive answer, or set of principles to help me answer the question. So I turn to the great folk on SO to help me find answers or guiding thoughts :)
SpecFlow is very useful for BDD in .NET. But when we talk about BDD are we just talking integration/acceptance tests, or are we also talking unit tests - a total replacement for TDD?
I've only used it on small projects, but I find that even for my unit tests, SpecFlow improves code documentation and thinking in terms of language. Converseley, I can't see the full code for a test in one place - as the steps are fragmented.
Now to you..........
EDIT: I forgot to mention that I see RSpec in the RoR community which uses BDD-style syntax for unit testing.
I've recently started to use SpecFlow for my BDD testing, but also, I still use unit and integration tests.
Basically, I split the tests into seperate projects:
Specs
Integration
Unit
My unit tests are for testing a single method and do not perform any database calls, or external references whatsoever. I use integration tests for single method calls (maybe sometime two) which do interact with an external resources, such as a database, or web service, etc.
I use BDD to describe tests which mimick the business/domain requirements of the project. For example, I would have specs for the invoice generation feature of a project; or for working with a shopping basket. These tests follow the
As a user, I want, In order to
type of semantics.
My advise is to split your tests based on your needs. Avoid trying to perform unit testing using SpecFlow.
We have started using Specflow even for our unit tests.
The main reason (and benefit) for this is that we find that it forces you to write the tests from a behavior point of view, which in turn forces you to write in a more implementation agnostic way and this ultimately results in tests which are less brittle and more refactoring friendly.
Sure this can also be done with standard unit testing frameworks, but you aren't guided that way as easily as we have found we are using specflow and the gherkin syntax.
There is some overhead setting things up for specflow, but we find this is quickly repaid when you have quite a few tests (due to the significant step reusability that you can get with specflow) or you need refactor your implementation.
Plus you get nice readable specs that are easy for newcomers to the team to understand.
Given:
Unit tests are test of (small) "units of code"
The customer of most “units of codes” are other programmers.
Part of the reason for having a unit test is to provide an example of how to call the code.
Therefore:
Clearly unit tests should normally be written in the programming language that the users of the “unit of code” will be calling it with.
However:
Sometimes data tables are needed to setup the conditions a unit test runs in.
Most unit test frameworks are not good at using tables of data.
Therefore:
Specflow may be the best option for some unit test, but should not be your default choose.
I see it as an integration testing which mean it doesn't replace your unit test cases written as part of your TDD process. Someone will have different opinion about this. IMHO unit test case only test the methods/functions and all the dependencies should be mocked and injected. When in it comes to integration testing, you will be injecting real dependencies instead of mocked one. You could do the same integration testing with any of the unit testing frameworks, but the BDD provides you cleaner way of explaining the integration test use case in a Domain Specific Language which is a plain English(or any localized language).
Ta,
Rajeesh
I used specflow for BDD testing on two different good sized applications. Once we worked through the kinks of the sentence naming conventions, it worked out pretty good. BA's and QA's, and even interns could write BDD tests for the application.
However, I ALSO used it for unit tests. Heresy! I can hear some of you scream. However, there were VERY good reasons for it. The system was responsible for making many calculations or determinations based off a lot of different data. With lots of unit tests that require all this data to be input for test purposes, it makes it a LOT easier to manage that data used for the unit tests via the table format provided by specflow. Effectively mocking the data repository in table format, allowing the different components to be vigorously tested.
I don't know if I would do it in every case, but in the ones I used it for, it made laying out the volumes of data necessary for for performing the unit tests so much easier and clearer.
In the end we are trying to deliver to the customer exactly what the customer wants and as such I really don't see the need to write unit tests in addition to SpecFlow. After all, it exercises the same code base. I am fairly new to BDD/ATDD/TDD but other than being "complete" and strictly adhering to TDD I'm finding it unnecessary to write more unit tests.
Now I suppose if the team was dispersed and the developer was not able to run the entire application then separate unit tests would be necessary but where the developer(s) has access to the entire code base and is able to run the application, then why bother write more tests.
Related
I'm really getting frustrated with learning how to properly develop software using TDD. It seems that everyone does it differently and in a different order. At this point, I'd just like to know what are all the considerations? This much is what I've come up with: I should use rspec, and capybara. With that said, what are all the different types of test I need to write, to have a well built and tested application. I'm looking for a list that comprises the area of my application being tested, the framework needed to test it, and any dependencies.
For example, it seems that people advise to start by unit testing your models, but when I watch tutorials on TDD it seems like they only write integration test. Am I missing something?
Well, the theme "how do you TDD" is as much out there in the open as the theme "how do you properly test?". In Ruby, and more specifically in Rails, rspec should be the tool to start with, but not be done with. RSpec allows you to write Unit Tests for your components, to test them separately. In the Rails context, that means:
test your models
test your controllers
test your views
test your helpers
test your routes
It is a very good tool not exactly rails-bound, it is also used to test other frameworks.
After you're done with RSpec, you should jump to cucumber. Cucumber (http://cukes.info/) is the most used tool (again, for the Rails environment) to write integration tests. You can then integrate capybara on cucumber.
After you're done with cucumber, you'll be done with having tested your application backend and (part of) its HTML output. That's when you should also test your javascript code. How to do that? First, you'll have to Unit test it. Jasmine (http://pivotal.github.com/jasmine/) is one of the tools you might use for the job.
Then you'll have to test its integration in your structure. How to do that? You'll come back to cucumber and integrate selenium (http://seleniumhq.org/) with your cucumber framework, and you'll be able to test your integration "live" in the browser, having access to your javascript magic and testing it on the spot.
So, after you're done with these steps, you'll have covered most of the necessary steps to have a well-integrated test environment. Are we done? Not really. You should also set a coverage tool (one available: https://github.com/colszowka/simplecov) to check if your code is being really well tested and no loose ends are left.
After you're done with these morose steps, you should also do one last thing, in case you are not developing it all alone and the team is big enough to make it still unmanageable by itself: you'll set a test server, which will do nothing other than run all the previous steps regularly and deliver notifications about its results.
So, all of this sets a good TDD environment for the interested developer. I only named the most used frameworks in the ruby/rails community for the different types of testing, but that doesn't mean there aren't other frameworks as or more suitable for your job. It still doesn't teach you how to test properly. For that there's more theory involved, and a lot of subdebates.
In case I forgot something, please write it in a comment below.
Besides that, you should approach how you test properly. Namely, are you going for the declarative or imperative approach?
Start simple and add more tools and techniques as you need them. There are many way to TDD an app because every app is different. One way to do that is to start with an end-to-end test with Rspec and Capybara (or Cucumber and Capybara) and then add more fine-grained tests as you need them.
You know you need more fine-grained tests when it takes more than a few minutes to make a Capybara test pass.
Also, if the domain of your application is non-trivial it might be more fruitful for you to start testing the domain first.
It depends! Try different approaches and see what works for you.
End-to-end development of real-world applications with TDD is an underdocumented activity indeed. It's true that you'll mostly find schoolbook examples, katas and theoretical articles out there. However, a few books take a more comprehensive and practical approach to TDD - GOOS for instance (highly recommended), and, to a lesser extent, Beck's Test Driven Development by Example, although they don't address RoR specifically.
The approach described in GOOS starts with writing end-to-end acceptance tests (integration tests, which may amount to RSpec tests in your case) but within that loop, you code as many TDD unit tests as you need to design your lower-level objects. When writing those you can basically start where you want -from the outer layers, the inner layers or just the parts of your application that are most convenient to you. As long as you mock out any dependency, they'll remain unit tests anyway.
I also have the same question when I started learning rails, there're so many tools or methods to make the test better but after spending to much time on that, I finally realized that you could simply forget the rule that you must do something or not, test something that you think it might have problem first, then somewhere else. Well ,it needs time.
that's just my point of view.
I am learning Behavior Driven Development with ASP.NET MVC and, based on a post from Steve Sanderson, understand that BDD can mean, at least, the following test types: individual units of code & UI interactions. Something similar is mentioned in this post. Do I need two different test frameworks if I want both unit and integration testing?
Unit testing repositories, controllers, & services using a context/specification framework, like MSpec. The results of testing with this will be useful to the development team.
Testing complete behaviors (integration) using a given/when/then framework, like SpecFlow with Watin. The results of this testing will be useful for my client.
The videos I have seen so far on using BDD have only been limited to testing the behaviour of entities without testing the behaviour of repositories, controllers, etc... Is there a sample project where I can see both automated Unit and Integration testing using a BDD approach?
Personally I use SpecFlow for building feature specific tests (i.e. "User creates new company record") where I'll sometimes (but not always) use Watin. For testing my respositories, or service classes, I'll use unit/integration tests with NUnit. Integration tests are for when I need to talk to the database during the test, unit is for when I simply run code in the target object under test without external interactions.
I would say that you don't need to use a BDD framework for your non UI tests. You can if you want, but there is no hard and fast rule on this. If you are going to do this, then I highly recommend creating more then one project for your tests. Keeping them split is a good idea, rather then mixing all the test into one project. You could name them:
MyProject.Tests.Features <-- For BDD
SpecFlow tests.
MyProject.Tests.Integration <-- For
tests that access an
external resource i.e. database.
MyProject.Tests.Unit
If you're not wanting to use two BDD frameworks, you can still use MSTest/NUnit in a BDD way. For example, this blog article describes a nice naming convention which is close to BDD, but aimed at MSTest/NUnit unit tests. You could use this for your non SpecFlow tests when your testing things like repositories.
In summary - you don't have to use SpecFlow and MSpec in your testing, but if you do, then I recommend separate test projects.
I generally agree with what Jason posted.
You might want to divide your specs into two categories, system/integration and unit-level tests. You can describe both categories with any framework, but keep in mind that code-only approaches (NUnit, MSpec, etc.) require a business analyst to be capable of writing C#. SpecFlow/Gherkin can be a better approach if you want to involve analysts and users in writing specifications. Since the syntax and rules (Given, When, Then) are easy to understand and writing specifications from a user's perspective are easy to jot down after little training. It's all about bridging the communication gap and having users helping your team form the ubiquitous language of your domain.
I recommend having specifications support both working "outside in" and "inside out". You may start with an "outside in" SpecFlow specification written by the user/analyst/product owner and work your way from "unimplemented" towards "green" writing the actual code. The code supporting the feature is developed using TDD with a more technically oriented framework like MSpec (the "inside out" part).
Here's a repository that use MSpec for both unit and integration tests: https://github.com/agross/duplicatefinder.
I am looking at SpecFlow examples, and it's MVC sample contains several alternatives for testing:
Acceptance tests based on validating results generated by controllers;
Integration tests using MvcIntegrationTestFramework;
Automated acceptance tests using Selenium;
Manual acceptance tests when tester is prompted to manually validate results.
I must say I am quite impressed with how well SpecFlow examples are written (and I managed to run them within minutes after download, just had to configure a database and install Selenium Remote Control server). Looking at the test alternatives I can see that most of them complement each other rather than being an alternative. I can think of the following combinations of these tests:
Controllers are tested in TDD style rather than using SpecFlow (I believe Given/When/Then type of tests should be applied on higher, end-to-end level; they should provide good code coverage for respective components;
MvcIntegrationTestFramework is useful when running integration tests during development sessions, these tests are also part of daily builds;
Although Selenium-based tests are automated, they are slow and are mainly to be started during QA sessions, to quickly validate that there are no broken logic in pages and site workflow;
Manual acceptance tests when tester is prompted to confirm result validity are mainly to verify page look and feel.
If you use SpecFlow, Cucumber or other BDD acceptance test framework in you Web development, can you please share your practices regarding choosing between different test types.
Thanks in advance.
It's all behaviour.
Given a particular context, when an event occurs (within a particular scope), then some outcome should happen.
The scope can be a whole application, a part of a system or a single class. Even a function behaves this way, with inputs as context and the output as outcome (you can use BDD for functional language as well!)
I tend to use Unit frameworks (NUnit, JUnit, RSpec, etc.) at a class or integration level, because the audience is technical. Sometimes I document the Given / When / Then in comments.
At a scenario level, I try to find out who actually wants to help read or write the scenarios. Even business stakeholders can read text containing a few dots and brackets, so the main reason for having a natural language framework like MSpec or JBehave is if they want to write scenarios themselves, or show them to people who will really be put off by the dots and brackets.
After that, I look at how the framework will play with the build system, and how we'll give the ability to read or write as appropriate to the interested stakeholders.
Here's an example I wrote to show the kind of thing you can do with scenarios using simple DSLs. This is just written in NUnit.
Here's an example in the same codebase showing Given, When, Then in class-level example comments.
I abstract the steps behind, then I put screens or pages behind those, then in the screens and pages I call whatever automation framework I'm using - which could be Selenium, Watir, WebRat, Microsoft UI Automation, etc.
The example I provided is itself an automation tool, so the scenarios are demonstrating the behaviour of the automation tool through demonstrating the behaviour of a fake gui, just in case that gets confusing. Hope it helps anyway!
Since acceptance tests are a kind of functional tests, the general goal is to test your application with them end-to-end. On the other hand, you might need to consider efficiency (how much effort is to implement the test automation), maintainability, performance and reliability of the test automation. It is also important that the test automation can easily fit into the development process, so that it supports a kind of "test first" approach (to support outside-in development).
So this is a trade off, that can be different for each situation (that's why we provided the alternatives).
I'm pretty sure, that today the most widely fitting option is to test at the controller layer. (Maybe later as UI and UI automation frameworks will evolve, this will change.)
I've been searching on how to do Unit testing and find that it is quite easy, but, what I want to know is, In a asp.net mvc application, what should be REALLY important to test and which methods you guys use?
I just can't find a clear answer on about WHAT TO REALLY TEST when programming unit tests.
I just don't want to make unnecessary tests and lose development time doing overkill tests.
You should unit test as much as possible of your application.
For every line of code you write, you need to verify that it works. If you don't unit test it, you need to test it in some other fashion. Even starting up the site and clicking around is a sort of testing.
When you compare unit testing with other sorts of testing (including running the site and manually using it), unit tests tend to give the best return of investment because they are relatively easy to write and maintain, and can give you rapid feedback on whether you just introduced a regression bug or not.
I'm not saying that there's no overhead in writing unit tests - there is, but there's overhead in any sort of testing, and a big overhead in not testing at all (because regression bugs slip through quite easily).
It's still good practice to supplement unit tests with other types of tests, but a good unit test suite offers an excellent regression test suite.
Ron Jeffries says "Test everything that could possibly break."
Someone else - I think it was Kent Beck, but I can't find a reference - says, "Only test the code you want to work."
Either of these is a pretty good strategy.
I actually don't think anything needs to be tested in MVC. I think all your business logic, rules etc need testing but the Views and Controllers?
The only real reason I can see to test a Controller is for integration testing. If all your business logic is correct then that should be a simple test always returning true.
Controllers should really only get data from the view and pass data to it so....
As for views, what sort of testing can be done there other than to open the view and see what it does?
When I write my projects there is next to no code in the controller and I put all the grunt in my business engine which I have extensive tests for.
Unit testing is good for testing of services/models. But when you need in testing of application functionality the better choice will be functional tests (i.e. Selenium)
At present, my development process flows like this:
I describe the expected behaviour as an integration test using using WebRat
I write the Ruby on Rails code to provide that behaviour, so passing the test
I refactor, ensuring the tests still pass at the end of the process
I write the next integration test
It seems to me that by definition, my integration tests are testing every model, controller and view that I can create. In reality, am I missing anything by not writing unit tests too?
I'm actually pretty sympathetic to your point of view here. I love Cucumber and I love RSpec -- and I use them both, but not always on the same code. For instance, I rarely write RSpec examples for Rails controllers these days, and I almost never write view specs. Most of my controllers are very similar and don't deviate much from the "stock" controller pattern -- which is already well-tested by Rails's own unit tests. Verifying the same behavior again doesn't gain much for the time it takes and the hassle of mocking all the models. With Cucumber at an integration level I can skip that mocking and get the essential verification I'm looking for. View testing is handled much more transparently in Cucumber most of the time as well. (Then I should see "foo" and so forth.)
But that isn't to say I don't use RSpec extensively in Rails. I use it for the places where my logic lives: models, controller filters, and view helpers. I also have a couple of projects that are almost all business logic, e.g. libraries or API adapters against complex third-party interfaces. For those I usually find myself using RSpec exclusively and skipping Cucumber.
As a heuristic, I'd suggest that you should strongly consider writing a unit test any time any of the following questions can be answered "Yes":
Is the code I'm writing more than trivially complicated?
Does this code exist primarily to give answers to other code?
Is this existing code that I'm refactoring (that doesn't already have a unit test)?
Have I found a bug in this code? (If so, write a unit test before fixing it so it never sneaks in again.)
Do I have to think for more than ten seconds about the most elegant way to implement this code?
Is my Spidey Sense tingling?
If none of the above is true, then maybe you can get away with just doing integration testing. Again, there are a lot of cases where that's reasonable. But if you do run into problems later, be prepared to pay the price -- and that price should include writing unit tests at any moment if they seem called for.
Integration tests are useful to verify that different parts of code are well integrated. They may involve all layers and cover all code but... when an integration test fails, will it tell you where the bug is located? I may be wrong but I don't think so. This will just tell you that there is a problem somewhere. On the other hand, when a real unit tests (written in isolation using mocks or stubs) fails, you know exactly in which unit the problem is located (this is actually the purpose of unit testing, verifying that a unit implements the expected behavior). In other words, unit tests and integration tests are both useful but they have different purposes.
Do you have any rake tasks? Custom capistrano code? Cron methods? An API? Monkeypatches? How about flex or iPhone app integration? A job runner?
In a typical Rails application, there's lots of code that isn't exercised by the HTML UI. So no, unless your app is incredibly simple, webrat tests won't be sufficient.