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I just finished writing a function to interpret GS1-128 codes (the data, not the barcode/datamatrix image) in (hopefully) any constellation they can come in.
I am now trying to thoroughly test the function.
All manually generated codes I have tried are working fine (first try, obviously), but generating error free GS1-128 codes by hand is a rather slow process and also flawed methodology since my understanding of creating a norm-conform code and my functions logic are obviously the same, but not nessccessarily correct.
I have already inquired at the local GS1 organization whether they have a list of known-good codes for testing they are allowed to hand out. The answer was no.
I have also searched on the internet for either a list or an automated means of generating codes (preferably with varried contents and orders od content) in bulk, neither yielded a helpful result.
I don't really know of any better place to ask this quiestion, so I'm asking this community, since I have the hope that someone might have one either lying around or has means of generating a reasonable (or unreasonable) amount of codes (the data, not the barcode/datamatrix image (although that would work just as well)) without too much effort.
If it's available I'd gladly take a list with decoded contents per code to further automate and scale up the testing, but I'm really not going to turn anything down :P
Hope whoever read this far is having a good day.
I would suggest that you take a look at the unit tests in the GS1 Barcode Syntax Engine, which comprehensively processes GS1 AI syntax messages:
https://github.com/gs1/gs1-syntax-engine/blob/main/src/c-lib/ai.c#L795
It's a shame that your GS1 Member Organisation were unable to refer you to their own tool.
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I have complex project without comments. The project is programed in Java but have more than one main class, use several .txt files like a template and use several .bat files. I don't know where to start and how to start discovering the project, because I need to make some changes in that project.
As with others I say this is a slow process.
However having done this in the past many times, this is my methodology:
Identify as many requirements that the code fulfils. This may give you the some reasons as to why certain things are the way they are when you look deeper. A common way of finding these is look for any tests that be available. The automated ones are best, but usually they're as missing as the comments.
Find the entry points to the code. These will give you places where you can poke the code to see how different inputs affect the flow. Common entry points are Code Loading 'Main' type functions, service interfaces, web page post backs etc..
Diagram the code. Look for tools that can build black/white box pictures of the code. For me this invaluable. I have on occasion printed out large listings and attacked then with markers and rulers. You're aim to create your own flow chart (mental or other wise) of the code flow.
Using the above (iteratively) build a set of outputs to the code that you think should occur, and add to these the outputs you may already know about such as logs, data files, database writes etc..
Finally if you have time, create some manual tests though preferably in automated test harnesses to verify the above. This where I start to involve the debugger to see detail in the code.
This methodology usually gives me confidence to make changes.
Note this is iterative process and can be done with portions of the code or overall as you see fit. I usually favour a top down approach to start with and then as I gain some insight I drill down till details become overwhelming and then I repeat. However this is just because my mind works in this way - you may be different. Good luck.
Find the main Main class. The starting point.
Start drawing a picture of the classes and the objects they own and the external entities they reference.
Follow all the branches until you can find a logical ending.
I've used UML reverse engineering tools in the past and while a visual picture is good, stepping through the code has always been the hardest and yet best methodology for me.
And, as you step through each piece you can add in your own comments..
I usually start with doxygen, turning on every extracting option (especially EXTRACT_ALL and EXTRACT_PRIVATE), and enable the SOURCE_BROWSER, HAVE_DOT, CALL_GRAPH and CALLER_GRAPH options (you also need to have dot installed). This gives good view of the software. For every function the calls are displayed and linked in a graph, also the sources are linked from there.
While doxygen is intended for C and C++, it also works with Java sources (set the OPTIMIZE_OUTPUT_JAVA option).
Auch. I'm afraid there is no speedy way to do this. Comment out a line (or two) -> test -> see what breaks. You could also put break statements here and there and run the debugger. That should give you some indication how you got there (ie. what the hierarchy between the classes is).
Hopefully the original developers used some patterns that you can recognize and make notes. Make lots of notes of everything. Start by trying to understand the high level structure and work down from there.
Be prepared to spend endless hours not understanding what the thing is doing.
Speak to the client and try to understand what the project is for, and what are all the things that it does. Someone somewhere had to put in some requirements for the stuff that's in there, if only in an email.
I would try to find the first entry point in the code closest to where you suspect you'll need to start making your changes, set a breakpoint, and start debugging. Check out the contents of local variables and work your way deeper as you get to become familiar with whats going on. Then, when you have a basic understanding of the area of code you're going to be working with, start fiddling with some small changes. Test your understanding of it. Try diagramming what you see happening. If you can do that confidently, you'll be able to decide if you need to go back and continue learning more about the code, or if you know enough to get done what you need to get done.
A start is to use an automated uml modeling tool (if you use eclipse you can use a plug-gin), and start creating UML diagrams of the various classes to see how they are related in a high level and visualize the code. This has helped many times
If there are log files being generated, have a look at it to understand the flow from the starting point (main class). Otherwise, put debug statements to understand the flow.
Ya, that sounds like a pretty bad spot to be in.
I would say that the best way is to just walk through the program line for line. Try to grasp the big picture in the code, and write alot of notes, both on paper and in comments in the code.
I would say, a good approach would be to generate documentation using javadoc or doxygen's class diagram feature, then as you run the code traverse through the class diagrams generated using doxygen and see who calls what. This works wonderfully for me everytime i am working on such a project.
I completely agree to most of the answers posted.
I can add to use a development tool that reverse engineering the code and create a class diagram, to have an overall picture of what is involved.
Then you need patience. But you will be a stronger and smarter developer when you'll get through...
Good luck!
One of the best and first things to do is to try to build and run the code. It might sound a bit simplistic but the problem when you take over undocumented code is that you can't even build it and run it. When have no clue were to start.
OK. Our product works. Beta testers are actually getting their stuff done. Time for the next iteration. But how to ensure quality? We need a tester!
How do I get someone fresh off the street started in testing? I have no clue on how to do it myself (I'm a developer, not a tester)!
We are a tiny team:
2 architects (as in buildings, not software, they are the domain experts here) figuring out what to build
me building it
and a new guy to do some testing before we push releases out
None of us has a clue on how to do this professionally. So far we have:
a bunch of virtual machines spanning the configurations we would like to test
various versions of windows
german and english, the two languages likely to be in use by our customers
the host software we are writing for (Autodesk Revit Architecture 2010, we are building a plugin for energy calculations)
a text document describing some tests I did (installed release xyz, did this, did that, etc.)
a bug tracking system the tester can add all the bugs he finds
I expect we will need a test script. But how? Who? What? When?
Why are you looking for "someone off the street"? To me, it sounds kind of like asking "I want to hire a new programmer, how do I get someone off the street and get him up to speed programming my software?". Why would you want to do that, over hiring someone who is a programmer already?
In your situation, which is that you don't know much about testing, I'd definitely think about hiring someone with experience in the field.
Specifically, I'd probably look for:
Someone with some experience performing tests under his belt (since you're going to want him actually doing tests).
Someone with some experience writing test plans/etc.
Someone with some experience running a QA team.
The last point is optional, but hopefully your team will be growing as your software grows, so it might make sense to get someone who can grow in the role as well (not to mention having the experience to help you decide when and how to grow the QA team).
Well, are you looking to expand your team with a tester? Have you considered just hiring a test specialist from a consultancy firm?
Before you get somebody to test, make sure you meet the requirements for testing. At a minimum you need:
A specification: Some authoritative source on what the application is supposed to do. This could be an expert that can answer any and all questions on exactly what the app is supposed to do, but the more that is written down and the more formally defined it is the better.
Time: Testing takes time. You can't hand off an application to the tester 30 minutes before it's supposed to go live and expect any worthwhile results. If you're doing waterfall development, testing will require a lot of time at the end. Lots of other development models let testing run in parallel with development, which saves a lot of time, but regardless of the model you use, testing will require more time than not testing.
If you don't have these two things, quality assurance is just a pipe dream.
Now if you do have those met, and you're trying to train somebody to test, here's my crash course on testing.
Fundamentally, testing an application means that you are attempting to ensure two things:
The program does what it is supposed to do.
The program does not do what it is not supposed to do.
That's the core mindset that I use. Building from that I approach things in terms of actions and attempt to verify:
An expected action with expected preconditions produces an expected effect.
An expected action with unexpected preconditions produces no effect or is handled appropriately.
An unexpected action produces no effect or is handled appropriately.
No unexpected effects occur.
Item 1 comes directly from the spec: You make sure that the program does what it is supposed to do.
Items 2 and 3 are where the art of testing comes in. What unexpected actions and preconditions can I perform? I could try to enter the wrong password. I could try to directly type in the URL of a supposedly secured page. I could try to paste odd unicode characters into a text field. I could try to put SQL or javascript code into a text field.
Item 4 is the infinite no-man's land of testing, the part that makes complete testing impossible. (2 and 3 are also infinite, but not as depressing to think about.) That doesn't mean you ignore it. You always keep an eye out for anything unusual. Also, sometimes inspiration strikes and you think of a possible way to cause an unexpected effect: "What happens if I log in between 11:59:59PM and 12:00:00AM on the third tuesday of the month? Oh look, it made me an administrator." Technical knowledge and a peek inside the black box help with coming up with scenarios like that.
There is a whole lot more to say about testing, but that's the bare minimum I can think of: The technical requirements and the approach to the problem.
Ideally, you'll need to give the tester:
training to make sure he knows the product to be tested.
documentation on what the expected results are.
test plans - what needs to be tested and how
a test tracking system to track what is being tested, what passed the tests, what needs to be fixed, etc. That system does not have to be too sophisticated, depending on the size of the project, an Excel spreadsheet may suffice.
In their podcast #64, Jeff and Joel discuss (among other things) what skills a good tester should possess. Transcript also available (about halfway down the page)
I've been learning what TDD is, and one question that comes to mind is what exactly is the "test". For example, do you call the webservice and then build the code to make it work? or is it more unit testing oriented?
In general the test may be...
unit test which tests an individual subcomponent of your software without any external dependencies to other classes
integration test which are tests that test the connection between two separate systems, ie. their integration capability
acceptance test for validating the functionality of the system
...and some others I've most likely temporarily forgotten for now.
In TDD, however, you're mostly focusing on the unit tests when creating your software.
It's entirely Unit Test driven.
The basic idea is to write the unit tests first, and then do the absolute minimum amount of work necessary to pass the tests.
Then write more tests to cover more of the requirements, and implement a bit more to make it pass.
It's an iterative process, with cycles of test writing, and then code writing.
Here are a couple of good articles by Unclebob
Three rules of TDD
TDD with Acceptance and Unit tests
I suggest you not to emphasize on Test because TDD is actually is a software development methodology, not a testing methodology.
I would say it is about unit testing and code coverage. It is about shipping bugless code and being able to make changes easily in the future.
See Uncle Bob's words of wisdom.
How I use it, it's unit testing oriented. Suppose I want a method that square ints I write this method :
int square(int x) { return null; }
and then write some tests like :
[Test]
TestSquare()
{
Assert.AreEqual(square(0),0);
Assert.AreEqual(square(1),1);
Assert.AreEqual(square(10),100);
Assert.AreEqual(square(-1),1);
Assert.AreEqual(square(-10),100);
....
}
Ok, maybe square is a bad example :-)
In each case I test expected behaviour and all borderline vals like maxint and zero and null-value (remember you can test on errors too) and see to it the test fails (which isn't hard :-)) then I keep working on the function until it works.
So : first a unit test that fails an covers what you want it to cover, then the method.
Generally, unit tests in "TDD" shouldn't involve any IO at all.
In fact, you'll have a ton more effectiveness if you write objects that do not create side effects (I/O is almost always, if not always, a side effect!), and define your the behavior of your class either in terms of return values of methods, or calls made to interfaces that have been passed into the object.
I just want to give my view on the topic which may help to understand TDD a bit more in a different way.
TDD is a design method that relies in testing first. because you asked about how the test is, ill go like this:
If you want to build an application, you know the purpose of what you want to build and you know generally that when you are done, or along the way you need to test it e.g check the values of variables you create by code inspection, of quickly drop a button that you can click on and will execute a part of code and pop up a dialog to show the result of the operation etc.
on the other hand TDD changes your mindset and i'll point out one of such ways. commonly , you just rely on the development environment like visual studio to detect errors as you code and compile and somewhere in your head, you know the requirement and just coding and testing via button and pop ups or code inspection. I call this style SDDD (Syntax debugging driven development ).
but when you are doing TDD, is a "semantic debugging driven development " because you write down your thoughts/ goals of your application first by using tests (which and a more dynamic and repeatable version of a white board) which tests the logic (or "semantic") of your application and fails whenever you have a semantic error even if you application passes syntax error (upon compilation).
by the way even though i said "you know the purpose of what you want to build ..", in practice you may not know or have all the information required to build the application , since TDD kind of forces you to write tests first, you are compelled to ask more questions about the functioning of the application at a very early stage of development rather than building a lot only to find out that a lot of what you have written is not required (or at lets not at the moment). you can really avoid wasting your precious time with TDD (even though it may not feel like that initially)
im looking for suggestion in which GUI tool is most appropriate for me to use in implementing my study. im using java language. i would like the graphics to simulate a house in which graphical changes apply without user inputs from mouse or keyboards. my user input is in the form of sms. thanks in advance guys. im hoping to animate it or simulate a smart home through the conditions i had set in my program. thnaks!
Your questions is very underspecified. I will assume that you are at the early stages of producing a hand-rolled home automation programs, you probably need:
an environment to let you test the core logic of the system (i.e. "If the system is in state X and I issue command Y, what does it actually do, and will I lose the contents of my freezer?")
an environment to let you test the SMS communications module
you may need a demo mode to show prospecitve customers what it does (this is my best guess at what is being requested here)
Now (3) could fill in for (1), but is a lot more programming effort, so from the start you probably want a simple text interface to do (1).
In general, you almost certainly want a modular system: a core logic system supported by at least two input models (SMS and keyboard), three output models (text debug, graphical demo, and control-line/wireless signals for the actual hardware), and various ancillary stuff (configuration reading, saved state handling). Come to think of it, since you probably need a way to probe the current state of the system, you should make the saved state and condition probe code share a single framework as well.