When do BDD scenarii become too much specific? - unit-testing

After a very inspiring training about TDD and BDD, I try to implement the methodology, using MSTest and Specflow. But I have a question where I'm stuck to:
I've written Acceptance Tests to validate a subsystem that we are working on.
Our system is a little distributed:
there is a 3rd party computer
with its own application running freely
with a third party database that we are accessing through tcp/ip
However my Specflow Scenario seems too much specialized for my own development set-up: it contains inputs that are valid only for me. In the example below, the ip adress is accessible mostly from me. And the target directory is namely a directory on my machine.
The accredited Tester/Validator, or the Product owner are likely not be able to launch the same test scenario, since they won't have access to this machine. But my developper colleages may not either.
#lastOne
Scenario: Get lattest 3rdParty OCR Data into specified directory
Given I indicate 'database' as the databaseName of third party computer
And I indicate '12.126.42.21' as the ipAddress of the third party computer
And I indicate 'user' as the databaseUser in third party computer
And I indicate 'c:\Temp\test_ocr\' as the destination path where to put the ocr data
And I indicate '2013020800009E' as the truck identifier to be associated with ocr data
When I call the OCR Application program
Then the destination path should contain correctly named xml file, with validated xml data, and jpg files about ocr data.
I am afraid I have some misconceptions about BDD. I am too specific in my scenario ?
If yes, where should I stop ?

I'm not sure your question is BDD specific but its still a good one.
I would normally recommend that all development is done with a continuous integration server running your tests every time you checkin, even for a private project that you work alone on. Even my own personal projects get this because TeamCity is free and the kids desktop at home is idle when I check in. The importance if this is more obvious if you work in a team, because it stops there ever being any doubt when you get the latest source code that it will build.
But it also stops the problem you have. You can tell very quickly when something is too specific because it doesn't work on both your own personal machine and the build machine. These problems exist whether you work in BDD, TDD, ATDD or any kind of testing.
Looking at your above example, I'd say it is very specific and also very brittle. If the third party PC is switched off one day, all your tests fail. If you were using Specflow to run unit tests then I'd recommend mocking most of your code so you can test without calling the test pc, but your example reads more like you are trying to do system/integration testing.
Instead of specifying all your parameters individually, why not give a name to whole bundle
Given Im using the test pc
you can then set many of them up in the binding and if you need to then tailor them so the tests still pass
[Given]
public void GivenImUsingTheTestPc()
{
if (Environment.ComputerName == "d1234")
{
ipadress = 1.2.3.4;
....
This obviously only moves the brittleness but at least it keeps you going for now

Related

Using Google Tests in embedded target?

I have started using google tests and google mocks in my embedded project.
Everything works fine, but currently I use it on my host machine when I develop code. It is the best option for TDD (it's fast), but I have to ocassionally run all code on the target board (STM32), because on my PC I use GCC, on the target ARMclang. So I need to validate that everything works fine on the target as well.
Here comes my question regarding Google Tests:
Is it possible to easily redirect all debug messages (test results) to a different peripherels than std::ostream, i.e. UART or USB so I could send test results to my host computer back?
I guess so, but there is quite a lot of code, it will take me weeks to dig into that and make it working. Maybe someone did that before and could give me hints which files need to be modified and replaced with my hardware wrappers? And does it makes a sense, or it is too complex (maybe there is to many OS dependencies) and it would be better to use another framework like CppuTest?
Thanks in advance.

Any suggestions on software development along the lines of quality assurance?

SUMMARY
The software I am working is an engineering analysis tool for renewable energy systems. It tests power outputs and things of this nature.
My current job task has been to test different configurations of said systems (i.e. use a evaporative cooling condenser instead of the default radiative cooling condenser via a drop down menu on the user interface) to ensure that the release version of this software functions across all spectrums as it should.
So far the process has been very simple to test: changing one factor of the base model and testing if the code functions properly as it should via the outputs generated.
How I need to pivot
But now we want to start testing combinations of tests. This change of workflow will be very tedious and time consuming for we are considering a factorial design approach in order to map out my plan of attack for what configurations to test, to ensure that all the code functions properly when changing multiple things. This could create many different types of configurations I will need to manually test.
All in all, does anyone have any suggestions for an alternative approach? I've been reading up on alternative software testing methods, but am not entirely sure if things like: regression testing, smoke testing, or sanity checks are better for this scenario or not.
Thanks!
EDIT
The software I am testing is being used on Visual Studios where I am utilizing the Google Test framework to manually test my system configurations.
Currently, each test that I create for a certain concentrated solar power system configuration demands that I manually find the difference in code (via WinMerge) between the default configuration (no changes made) to the alternative configuration. I use the code differences in Google Test Framework to simulate what that alternative config. should output by testing it against the accepted output values.
It's only going to get more complicated, with an aspect of manual user interface needed ... or so it seems to me.
How can I automate such a testing suite, when I'm needed to do so much back end work?
As per what I understand, to avoid the manual effort of testing too many combinations, an automation testing tool is needed in this case. If the software that you are testing is browser based, then Selenium is a good candidate. But if the tool is run as an application on Windows or Mac, then some other automation testing tool that supports Win/Mac apps would be needed. The idea is to create test suites with the different combinations and set the expected results for one time. Once the suite is ready, it can be run after any change to the software to verify that all the combinations work as expected without doing any manual work. However there would be an effort involved to create the test suite in the first place and then maintain it if the new scenarios occur or the expected results need to be modified.
It would be a pain to test all the many combinations manually each time, automation testing can surely ease that.

store results of automatic tests and show results in a web UI

I'm looking for a piece (or a set) of software that allows to store the outcome (ok/failed) of an automatic test and additional information (the test protocol to see the exact reason for a failure and the device state at the end of a test run as a compressed archive). The results should be accessible via a web UI.
I don't need fancy pie charts or colored graphs. A simple table is enough. However, the user should be able to filter for specific test runs and/or specific tests. The test runs should have a sane name (like the version of the software that was tested, not just some number).
Currently the build system includes unit tests based on cmake/ctest whose results should be included. Furthermore, integration testing will be done in the future, where the actual tests will run on embedded hardware controlled via network by a shell script or similar. The format of the test results is therefore flexible and could be something like subunit or TAP, if that helps.
I have played around with Jenkins, which is said to be great for automatic tests, but the plugins I tried to make that work don't seem to interact well. To be specific: the test results analyzer plugin doesn't show tests imported with the TAP plugin, and the names of the test runs are just a meaningless build number, although I used the Job Name Setter plugin to set a sensible job name. The filtering options are limited, too.
My somewhat uneducated guess is that I'll stumple about similar issues if I try other random tools of the same class like Jenkins.
Is anyone aware of a solution for my described testing scenario? Lightweight/open source software is preferred.

Integration testing - can it be done right?

I used TDD as a development style on some projects in the past two years, but I always get stuck on the same point: how can I test the integration of the various parts of my program?
What I am currently doing is writing a testcase per class (this is my rule of thumb: a "unit" is a class, and each class has one or more testcases). I try to resolve dependencies by using mocks and stubs and this works really well as each class can be tested independently. After some coding, all important classes are tested. I then "wire" them together using an IoC container. And here I am stuck: How to test if the wiring was successfull and the objects interact the way I want?
An example: Think of a web application. There is a controller class which takes an array of ids, uses a repository to fetch the records based on these ids and then iterates over the records and writes them as a string to an outfile.
To make it simple, there would be three classes: Controller, Repository, OutfileWriter. Each of them is tested in isolation.
What I would do in order to test the "real" application: making the http request (either manually or automated) with some ids from the database and then look in the filesystem if the file was written. Of course this process could be automated, but still: doesn´t that duplicate the test-logic? Is this what is called an "integration test"? In a book i recently read about Unit Testing it seemed to me that integration testing was more of an anti-pattern?
IMO, and I have no literature to back me on this, but the key difference between our various forms of testing is scope,
Unit testing is testing isolated pieces of functionality [typically a method or stateful class]
Integration testing is testing the interaction of two or more dependent pieces [typically a service and consumer, or even a database connection, or connection to some other remote service]
System integration testing is testing of a system end to end [a special case of integration testing]
If you are familiar with unit testing, then it should come as no surprise that there is no such thing as a perfect or 'magic-bullet' test. Integration and system integration testing is very much like unit testing, in that each is a suite of tests set to verify a certain kind of behavior.
For each test, you set the scope which then dictates the input and expected output. You then execute the test, and evaluate the actual to the expected.
In practice, you may have a good idea how the system works, and so writing typical positive and negative path tests will come naturally. However, for any application of sufficient complexity, it is unreasonable to expect total coverage of every possible scenario.
Unfortunately, this means unexpected scenarios will crop up in Quality Assurance [QA], PreProduction [PP], and Production [Prod] cycles. At which point, your attempts to replicate these scenarios in dev should make their way into your integration and system integration suites as automated tests.
Hope this helps, :)
ps: pet-peeve #1: managers or devs calling integration and system integration tests "unit tests" simply because nUnit or MsTest was used to automate it ...
What you describe is indeed integration testing (more or less). And no, it is not an antipattern, but a necessary part of the sw development lifecycle.
Any reasonably complicated program is more than the sum of its parts. So however well you unit test it, you still have not much clue about whether the whole system is going to work as expected.
There are several aspects of why it is so:
unit tests are performed in an isolated environment, so they can't say anything about how the parts of the program are working together in real life
the "unit tester hat" easily limits one's view, so there are whole classes of factors which the developers simply don't recognize as something that needs to be tested*
even if they do, there are things which can't be reasonably tested in unit tests - e.g. how do you test whether your app server survives under high load, or if the DB connection goes down in the middle of a request?
* One example I just read from Luke Hohmann's book Beyond Software Architecture: in an app which applied strong antipiracy defense by creating and maintaining a "snapshot" of the IDs of HW components in the actual machine, the developers had the code very well covered with unit tests. Then QA managed to crash the app in 10 minutes by trying it out on a machine without a network card. As it turned out, since the developers were working on Macs, they took it for granted that the machine has a network card whose MAC address can be incorporated into the snapshot...
What I would do in order to test the
"real" application: making the http
request (either manually or automated)
with some ids from the database and
then look in the filesystem if the
file was written. Of course this
process could be automated, but still:
doesn´t that duplicate the test-logic?
Maybe you are duplicated code, but you are not duplicating efforts. Unit tests and integrations tests serve two different purposes, and usually both purposes are desired in the SDLC. If possible factor out code used for both unit/integration tests into a common library. I would also try to have separate projects for your unit/integration tests b/c
your unit tests should be ran separately (fast and no dependencies). Your integration tests will be more brittle and break often so you probably will have a different policy for running/maintaining those tests.
Is this what is called an "integration
test"?
Yes indeed it is.
In an integration test, just as in a unit test you need to validate what happened in the test. In your example you specified an OutfileWriter, You would need some mechanism to verify that the file and data is good. You really want to automate this so you might want to have a:
Class OutFilevalidator {
function isCorrect(fName, dataList) {
// open file read data and
// validation logic
}
You might review "Taming the Beast", a presentation by Markus Clermont and John Thomas about automated testing of AJAX applications.
YouTube Video
Very rough summary of a relevant piece: you want to use the smallest testing technique you can for any specific verification. Spelling the same idea another way, you are trying to minimize the time required to run all of the tests, without sacrificing any information.
The larger tests, therefore are mostly about making sure that the plumbing is right - is Tab A actually in slot A, rather than slot B; do both components agree that length is measured in meters, rather than feet, and so on.
There's going to be duplication in which code paths are executed, and possibly you will reuse some of the setup and verification code, but I wouldn't normally expect your integration tests to include the same level of combinatoric explosion that would happen at a unit level.
Driving your TDD with BDD would cover most of this for you. You can use Cucumber / SpecFlow, with WatiR / WatiN. For each feature it has one or more scenarios, and you work on one scenario (behaviour) at a time, and when it passes, you move onto the next scenario until the feature is complete.
To complete a scenario, you have to use TDD to drive the code necessary to make each step in the current scenario pass. The scenarios are agnostic to your back end implementation, however they verify that your implementation works; if there is something that isn't working in the web app for that feature, the behaviour needs to be in a scenario.
You can of course use integration testing, as others pointed out.

Unit/integration testing Asterisk configuration

Unit and integration testing is usually performed as part of a development process, of course. I'm looking for ways to use this methodology in configuration of an existing system, in this case the Asterisk soft PBX.
In the case of Asterisk, the configuration file is as much a programming language as anything else, complete with loops, jumps, conditionals, etc., and can get quite complex. Changes to the configuration often suffers from the same problems as changes to a complex software product - it can be hard to foresee all the effects without tests in place. It's made worse by the fact that the nature of the system is to communicate with external entities, i.e. make phone calls.
I have a few ideas about testing the system using call files (to create specific calls between extensions) while watching the manager interface for generated events. A test could then watch for an expected result, i.e. dialling *99# should result in the Voicemail application getting called.
The flaws are obvious - it doesn't test the actual result, only what the system thinks is the result, and it probably requires some modification of the system under test. It's also really hard to write these tests robustly enough to only trigger on the expected output, especially if the system is in use (i.e. there are other calls in progress).
Is what I want, a testing system for Asterisk, impossible? If not, do you have any ideas about ways to go about this in a reasonable manner? I'm willing to put a fair amount of development time into this and release the result under a friendly license, but I'm unsure about the best way to approach it.
This is obviously an old question, so there's a good chance that when the original answers were posted here that Asterisk did not support unit / integration testing to the extent that it does today (although the Unit Test Framework API went in on 12/22/09, so that, at least, did exist).
The unit testing framework (David's e-mail from the dev list here) lets you execute unit tests directly within Asterisk. Tests are registered with the framework and can be executed / viewed through the CLI. Since this is all part of Asterisk, the tests are compiled into the executable. You do have to configure Asterisk with the --enable-dev-mode option, and mark the tests for compilation using the menuselect tool (some applications, like app_voicemail, automatically register tests - but they're the minority).
Writing unit tests is fairly straight-forward - and while it (obviously) isn't as fully featured as a commercial unit test framework, it gets the job done and can be enhanced as needed.
That most likely isn't what the majority of Asterisk users are going to want to use - although Asterisk developers are highly encouraged to check it out. Both users and developers are probably interested in integration tests, which the Asterisk Test Suite provides. At its core, the Test Suite is a python script that executes other scripts - be they lua, python, etc. The Test Suite comes with a set of python and lua libraries that help to orchestrate and execute multiple Asterisk instances. Test writers can use third party applications such as SIPp or Asterisk interfaces (AMI, AGI) or a combination thereof to test the hosted Asterisk instance(s).
There are close to 200 tests now in the Test Suite, with more being added on a fairly regular basis. You could obviously write your own tests that exercise your Asterisk configuration and have them managed by the Test Suite - if they're generic enough, you could submit them for inclusion in the Test Suite as well.
Note that the Test Suite can be a bit tricky to set up - Leif wrote a good blog post on setting up the Test Suite here.
Well, it depends on what you are testing. There are a lot of ways to handle this sort of thing. My preference is to use Asterisk Call Files bundled with dialplan code. EG: Create a callfile to dial some public number, once it is answered, hop back to the specified dialplan context and perform all of my testing logic (play soundfiles, listen for keypresses, etc.)
I wrote an Asterisk call file library which makes this sort of testing EXTREMELY easy. It has a lot of documentation / examples too, check it out here: http://pycall.org/. That may help you.
Good luck!
You could create a set of specific scenarios and use Asterisk's MixMonitor command to record these calls. This would enable you to establish a set of sound recordings that were normative for your system for these tests, and use an automated sound file comparison tool (Perhaps something from comparing-sound-files-if-not-completely-identical?) to examine the results. Just an idea.
Unit testing as opposed to integration testing means your code is supposed to be architectured so the logic itself is insulated from external dependencies. You said "the configuration file is as much a programming language as anything else" but that's the thing --- real languages has not just control flow but abstraction capabilities, which allow you to write the logic in a way that can be unit tested. That's why I keep logic outside of asterisk as much as possible.
For integration testing, script linphonec to drive your application, and grep the asterisk console to see what it's doing.
You can use docker, and fire up temporary asterisk instances for each test.