Tips for getting started with testing for first large app?

Hi all,

Well I have this fairly large application with restful authentication and a few other plugins in it. I developed it wholly otherwise. This is my first ROR app. And I learnt of Test Driven Development quite late. Ive reached the point where I need to cover my code with good test coverage. Ive done quite a lot of reading on testing but I still need to take the plunge into it and I have no idea where to start.

My request to those of you out there with the experience to put me in the right direction..

a few questions..

- should i start with unit tests? how paranoid should i be about them (if at all there's a unit of measurement for that)? - i understand too much dependency on fixtures can make my tests brittle. So i keep fixtures to a minimum? when exactly should I absolutely use a fixture? - what tools should i definitely use besides test/unit? RSpec, Autotest, Cucumber, Selenium, ... ?

Any and many tips welcome as welcome can be!

What would probably be most important is how do I analyze my code to see what tests are most important and start writing them? How do I approach writing tests? Thank you!

My advise:

- Don't bother with RSpec's hype. I tried it and got me pissed off so many times. Don't care about autospec, it will distract you more than it will help. Test::Unit is much better to use. AWDWR has a good enough chapter to get you started.

- Use mocha to mock and/or stub your method calls so that you test objects as isolated as possible from other objects.

- rcov can come in handy to know what parts of your app are not yet tested. Be careful: 100% test coverage, doesn't mean your app is still correctly tested.

- Don't ever use fixtures at all! Run away from any person who tells you they are fine, even if he is famous and rich.

- Write your tests (even unit tests) so that they hit DB as least as possible. When tests have to hit DB such as :include or :joins, then setup sqlite in-memory for faster testing.

- I have tried plenty factories: Machinist, factory girl, etc. I even wrote my own, but once you understand how to write tests that don't hit DB, you'll discover you will probably not need a factory at all. Except when you must hit DB, it can be a little bit easier to insert valid objects in DB. But at the beginning don't bother.

- use a notifier plugin on your production server to catch any additional edge case you haven't thought of (I use getexceptional), and write tests to prevent against them in the future

Writing tests is easy when you know how to write them and which tools to use.

Remember to have fun. If you are not having fun (even writing tests) then something is wrong.

Fernando Perez wrote:

My advise:

- Don't bother with RSpec's hype. I tried it and got me pissed off so many times.

I completely disagree. RSpec works very well, and its syntax is generally more natural (at least to me) than Test::Unit. In what way does RSpec not work for you?

Don't care about autospec, it will distract you more than it will help.

Again, I disagree 100%. I find it extremely helpful to get immediate feedback when my tests break. If you find autospec "distracting", I wonder if you're really paying enough attention to your tests...

[...]

- Use mocha to mock and/or stub your method calls so that you test objects as isolated as possible from other objects.

Yes. Mock everything that isn't what you're trying to test. (You only need Mocha if you're not using RSpec, which has its own mocking framework; however, it too will work with Mocha if you prefer it.)

- rcov can come in handy to know what parts of your app are not yet tested. Be careful: 100% test coverage, doesn't mean your app is still correctly tested.

Heck yes.

- Don't ever use fixtures at all! Run away from any person who tells you they are fine, even if he is famous and rich.

Agreed, with the possible caveat that Phlip seems to like them, and I trust everything *else* he says about testing. :slight_smile:

- Write your tests (even unit tests) so that they hit DB as least as possible.

Yes, but don't go through silly contortions to religiously avoid the DB altogether if it's more trouble than it's worth. RSpec's mock_model and stub_model are lovely here.

When tests have to hit DB such as :include or :joins, then setup sqlite in-memory for faster testing.

I don't see how this would work if you're using the DB in any reasonably sophisticated way, given that SQLite tends not to support such things.

[...]

- use a notifier plugin on your production server to catch any additional edge case you haven't thought of (I use getexceptional), and write tests to prevent against them in the future

Good advice.

Writing tests is easy when you know how to write them and which tools to use.

Remember to have fun. If you are not having fun (even writing tests) then something is wrong.

:slight_smile:

Best,

Ram wrote:

Well I have this fairly large application with restful authentication and a few other plugins in it. I developed it wholly otherwise. This is my first ROR app. And I learnt of Test Driven Development quite late. Ive reached the point where I need to cover my code with good test coverage.

Open a new Rails project in a new folder.

Rewrite every tiny detail of your old project into the new one.

If your old project has a model Foo, you start with script/generate model Foo, and get the foo_test.rb. You edit that to write a _useful_ test on one or two fields of Foo, and you pass the test by adding those fields to the migration and doing something with them in a method inside Foo.

(BTW, don't add a migration for each field - edit the existing migrations until you deploy them...)

Going this way prevents you from cheating, and helps you refactor. The new project should be finished very soon.

- should i start with unit tests? how paranoid should i be about them (if at all there's a unit of measurement for that)?

The test to code ratio should be 2:1. And start with useful features, not layers. To write a useful feature, write new tests and code into each layer that it needs.

- i understand too much dependency on fixtures can make my tests brittle. So i keep fixtures to a minimum? when exactly should I absolutely use a fixture?

Using my schedule, your fixtures will not be brittle. Just don't write assertions that expect useless things, like a count of found records. Test that all the records matched the find criteria.

- what tools should i definitely use besides test/unit? RSpec, Autotest, Cucumber, Selenium, ... ?

Those are mostly for documenting features to customers, not for TDD. Stick with unit tests, because RSpec would only add clutter if used as a TDD tool.

Autotest is because all the Rails editors truly suck, and do not let you run one test at a time. (Yes, textmate lets you run one test at a time - if you rotate the freaking document back to the correct test between every edit. The quality of these editors makes me wonder if anyone who develops them actually uses TDD.)

What would probably be most important is how do I analyze my code to see what tests are most important and start writing them? How do I approach writing tests?

Add features to your new project in order from highest business value and on down.

I completely disagree. RSpec works very well, and its syntax is generally more natural (at least to me) than Test::Unit. In what way does RSpec not work for you?

Each time I would write a test, something would go wrong in the spec, specially when specing controllers, so I only speced models. With Test::Unit everything works well and I can test my controllers and views so easily, I definitely don't need to watch any screencast to teach me how it works.

Moreover to my great surprise, Test::Unit's syntax is now pretty so you can write:

test "..." do

end

And behind the scenes it transforms it into def my_cool_test_with_plenty_underscores

I prefer 100 times test::unit to rspec, and when people ask about which tool to use, I recommend test::unit and I am glad to share my experience in testing so people won't do the same mistakes I did.

Again, I disagree 100%. I find it extremely helpful to get immediate feedback when my tests break. If you find autospec "distracting", I wonder if you're really paying enough attention to your tests...

No autospec is distracting as you often find yourself waiting for the test result, I won't even talk about growl which makes things even worse.

I got fed up when saving 3 files quickly and one after the other just because I did some indentation editing. Autospec would then run 3 times for nothing! Waste of time and resource. I prefer to run my tests manually.

Yes, but don't go through silly contortions to religiously avoid the DB altogether if it's more trouble than it's worth.

You are right. But for instance, instead of update_attributes I prefer to set the attributes and then call save! which I can stub in a test and still have the attributes get set, assert their values and save a slow DB hit.

By doing this I divided by 10 my testing time!!! Tests that hit DB are in their own file so that they don't slow down the other tests.

I don't see how this would work if you're using the DB in any reasonably sophisticated way, given that SQLite tends not to support such things.

What things does sqlite not support? joins?

Pick your poison whether it is rspec, test/unit, whatever, as long as you test, your choice is always a good one.

The test to code ratio should be 2:1.

That's BS. Even with a ratio of 10:1, if the tests are not smart, your app could have a bug and you would still not detect it. And remember that the higher the ratio, the more pain it will be to maintain the tests. So don't care about ratio.

Autotest is because all the Rails editors truly suck, and do not let you run one test at a time.

Is there a benefit to run 1 test at a time? I don't mind running 20 tests each time because they take less then 1 second to perform.

Marnen Laibow-Koser wrote:

Yes. Mock everything that isn't what you're trying to test.

Absolutely false. Mock almost nothing - the clock, the wire out of your workstation, and system errors.

Everything else should be so clean and decoupled that you can use it as stubs without mocking it. Mocks just tell your tests what they think they want to hear, and the mocks interfere with refactoring and decoupling.

Marnen Laibow-Koser wrote:

- Don't bother with RSpec's hype. I tried it and got me pissed off so many times.

I completely disagree. RSpec works very well, and its syntax is generally more natural (at least to me) than Test::Unit. In what way does RSpec not work for you?

RSpec is for BDD, like FIT or FITnesse. It's for communicating with your business-side analysts about all your features. For raw development, it adds clutter to the syntax without adding much new innovation to the test flow.

And, yes, all the developers are eating it up like popcorn...

Don't care about autospec, it will distract you more than it will help.

Again, I disagree 100%. I find it extremely helpful to get immediate feedback when my tests break. If you find autospec "distracting", I wonder if you're really paying enough attention to your tests...

Right - leave it running and save your files over and over again. Each time, practice successfully predicting what the tests will do.

And it bears repeating that TDD requires writing new tests and _watching_them_fail_, before adding the tested code. Don't just go write the test and then write the code. Don't write the code and then get around to testing what you got. Only write new code in response to failing tests.

And refactor refactor refactor. If your boss doesn't like it, keep refactoring until you get fired!

- Don't ever use fixtures at all! Run away from any person who tells you they are fine, even if he is famous and rich.

Agreed, with the possible caveat that Phlip seems to like them, and I trust everything *else* he says about testing. :slight_smile:

I _enjoy_ their fragility (in their current incarnation). It forces you to review your tests.

If anything in TDD is fragile, or leads to too much debugging (p statements), revert and try again. TDD makes fragility an asset.

- Write your tests (even unit tests) so that they hit DB as least as possible.

Yes, but don't go through silly contortions to religiously avoid the DB altogether if it's more trouble than it's worth. RSpec's mock_model and stub_model are lovely here.

Again, use the database to provide ready-made objects, and TDD your find() statements at the db. The decoupling will come, and "don't hit the db in testing" is all but a myth. (Darn you, Mike Feathers!)

Writing tests is easy when you know how to write them and which tools to use.

Remember to have fun. If you are not having fun (even writing tests) then something is wrong.

:slight_smile:

Yep. Tests should be easier and easier to write, until you feel guilty and think they must not be doing anything for you.

Phlip wrote: [...]

RSpec is for BDD, like FIT or FITnesse.

I would not say that FIT is a BDD tool, at least the way I understand that term.

It's for communicating with your business-side analysts about all your features.

No. That's what a tool like FITnesse or Cucumber is for. Perhaps your usage patterns are different, but for me at least, RSpec is for describing the behavior of modules, but at a much more technical level than business-side analysts would be interested in. I can't see using RSpec for business-domain tests at all!

For raw development, it adds clutter to the syntax without adding much new innovation to the test flow.

How so? I use RSpec for all raw development, largely for two reasons:

* I like the syntax.

* I like the focus on external interface rather than (Test::Unit's orientation toward?) internal behavior.

Where's the clutter? I really don't understand. Test::Unit feels *far* more cluttered to me, or did the last time I tried it.

And, yes, all the developers are eating it up like popcorn...

Sure! It's fun to use. :slight_smile:

[...]

And it bears repeating that TDD requires writing new tests and _watching_them_fail_, before adding the tested code. Don't just go write the test and then write the code. Don't write the code and then get around to testing what you got. Only write new code in response to failing tests.

I agree wholeheartedly (although in practice I'm not always as good at this as I should be).

[regarding fixtures]

I _enjoy_ their fragility (in their current incarnation). It forces you to review your tests.

I *really* don't understand this. Could you clarify?

If anything in TDD is fragile, or leads to too much debugging (p statements), revert and try again.

Doesn't this contradict the previous sentence?

TDD makes fragility an asset.

Doesn't *this* contradict the previous sentence?

[...]

Again, use the database to provide ready-made objects, and TDD your find() statements at the db. The decoupling will come, and "don't hit the db in testing" is all but a myth. (Darn you, Mike Feathers!)

It's probably a very good general idea (or ideal), but Rails ActiveRecord is too intimate with the DB to make it practical. I *do* think it's worth not having the tests *overly* dependent on the DB, though.

<sarcasm>But Jay Fields says that Rails tests shouldn't touch the DB. That's reason enough to agree with you that it's a myth.</sarcasm>

Writing tests is easy when you know how to write them and which tools to use.

Remember to have fun. If you are not having fun (even writing tests) then something is wrong.

:slight_smile:

Yep. Tests should be easier and easier to write, until you feel guilty and think they must not be doing anything for you.

I like that. But Master Phlip, I still think my tests are significant...I guess I have not yet achieved enlightenment!

--    Phlip

Best,

I _enjoy_ their fragility (in their current incarnation). It forces you to review your tests.

Fixtures make tests really slow, and they will eventually not reflect the actual model if you forget to update some attribute you changed. Moreover, you have to actually open the fixture file to know what's in it. I prefer to setup each test inside the test method so that I can immediately predict what should be the end result.

The decoupling will come, and "don't hit the db in testing" is all but a myth. (Darn you, Mike Feathers!)

Although everybody talks about him, I still don't know who he is... Anyway, I got the idea of not hitting the DB from Jay Fields, and from my own experience. Havin super fast tests is so enjoyable.

Absolutely false. Mock almost nothing - the clock, the wire out of your workstation, and system errors.

I think nobody is right nor wrong. The truth lies somewhere in between. I know that mocking, subbing and using unsaved objects can let in some bugs in my tests, but on the other hand it speeds up the tests. So I guess some objects can be mocked/stubbed/unsaved in order to save time, and some objects must be saved in order to make sure they are valid and legit in DB.

What's funny is that in 2009, there is still a lot of debate about the testing workflow, although programming has been around for a few years :slight_smile:

From: rubyonrails-talk@googlegroups.com [mailto:rubyonrails- talk@googlegroups.com] On Behalf Of Marnen Laibow-Koser Sent: Friday, April 17, 2009 10:56 AM To: rubyonrails-talk@googlegroups.com Subject: [Rails] Re: Tips for getting started with testing for first large app?

Phlip wrote: [...] > > RSpec is for BDD, like FIT or FITnesse.

I would not say that FIT is a BDD tool, at least the way I understand that term.

> It's for communicating with your > business-side analysts about all your features.

No. That's what a tool like FITnesse or Cucumber is for. Perhaps your usage patterns are different, but for me at least, RSpec is for describing the behavior of modules, but at a much more technical level than business-side analysts would be interested in. I can't see using RSpec for business-domain tests at all!

I agree with this. I think that BDD is just a different way of thinking about TDD, to better determine what exactly to test. Introducing BDD - Dan North & Associates Limited is one of my favorite articles on the subject.

Brandon

Concerning fixtures I started with fixtures, then in my second attempt to be a good tester I used factory girl, that worked fine for me. In my current third attempt, after upgrading to rails 2.3.2, I do not know how to proceed.

I have a lot of dependencies, which makes fixtures very hard and time consuming to use, but you learn a lot about your application when you use them. (Are there any tools that generates fixtures considering all associations?). Most people tell you that you should use a factory approach instead (see e.g. the other replies about fixtures) and I am thinking of using machinist, but ..... I hesitate.

The reason is that the rails developing team has selected the fixture approach (which are their reasons?) and the development of rails seems to follow that line. Is it not then wiser to go that way and take advantage of the improvements and tools that will be realized?

So what to select factories or fixtures ???

Marnen Laibow-Koser wrote:

How so? I use RSpec for all raw development, largely for two reasons:

* I like the syntax.

you.should be(:flogged)

[regarding fixtures]

I _enjoy_ their fragility (in their current incarnation). It forces you to review your tests.

I *really* don't understand this. Could you clarify?

When we say "fragile", we mean a test failed because we changed the fixtures for another test.

When we say "failed", we mean SUCCEEDED in SLOWING YOU DOWN. A car has brakes, headlights, and red lights not so we can stop, but so we can go very fast between stoppings.

When another test fails unexpectedly, you look at it and think about it. It might remind you of the original meaning of the fixture you are changing. It might force you to improve the assertion, to actually detect that test's situation better.

Or it might not, and you just get pissed off, and make a better change to the fixtures, or you might clone your fixture, or you might even start abusing mocks in frustration.

Either way, it's the overlap between tests, test-side code, and production code, that keeps everyone honest.

If anything in TDD is fragile, or leads to too much debugging (p statements), revert and try again.

Doesn't this contradict the previous sentence?

Revert early and often.

TDD makes fragility an asset.

Doesn't *this* contradict the previous sentence?

Reverting forces you to try a narrower change next time. Narrow changes are overwhelmingly better than wide sweeping changes.

Hans wrote:

Concerning fixtures I started with fixtures, then in my second attempt to be a good tester I used factory girl, that worked fine for me. In my current third attempt, after upgrading to rails 2.3.2, I do not know how to proceed.

I have a lot of dependencies, which makes fixtures very hard and time consuming to use

Expensive setup is a design smell. How about all your tests only use the fewest records possible?

The reason is that the rails developing team has selected the fixture approach (which are their reasons?) and the development of rails seems to follow that line. Is it not then wiser to go that way and take advantage of the improvements and tools that will be realized?

The reason the Rails team went with the current style of Fixtures was because in 2004 there was _nothing_ in the sector "TDD for databases, with migrations and refactoring", besides high-end guru consultant work at big companies. So the Railsters thought outside the box, and decided to load a complete DB for each test. To remain efficient, they loaded YAML directly into INSERT statements, bypassing the models.

For the first hundred records, that's not fragile...

So what to select factories or fixtures ???

Write your first test and let it tell you. The point of all of this is nothing is carved in stone...

Marnen Laibow-Koser wrote:

Mock almost nothing - the clock, the wire out of your workstation, and system errors.

I was at a loss to understand this until I read the following sentence.

Only mock things that are too expensive to call directly.

We are not writing QA "Unit Tests" - the kind CPU manufacturers write. They need pure isolation between units, so when a test fails it only implicates one unit. TDD does not do that.

Stub everything that isn't what you're directly testing. If for some reason you can't stub it, *then* mock it.

Or more simply:

If it isn't what you're testing, fake it!

Is that a more acceptable method?

No. I meant "expensive setup is a design smell".

Given an object model Post -> Author -> Access, a test on the Post->Author relationship could conceivably ignore the Access. And a test on Author->Access could ignore Post. The -> goes nowhere; it is stubbed.

Fixtures are among the systems that keep object models easy to whip out and use. If our system were as coupled as a Vendor-Lock-In system, such as MFC, we can't just create one object. We have to pull in everything just to construct and use one stinking CEdit control. Don't do that. All objects should construct cleanly without their runtime dependencies, if you don't need them.

and the mocks interfere with refactoring and decoupling.

How? By making a test too dependent on another object's interface? But don't stubs do that too?

When you change the raw object, what part of the system forces you to remember to change the mock the same way?

Marnen Laibow-Koser wrote:

We are not writing QA "Unit Tests" - the kind CPU manufacturers write. They need pure isolation between units, so when a test fails it only implicates one unit.

Aren't we, though? What's the point of a test that doesn't tell you what failed?

Under TDD, the element that failed must be among your recent edits. Therefor, tests are free to cross-polinate any of your modules together...

No. I meant "expensive setup is a design smell".

Then I guess I shouldn't be using Rails. I don't know how to test anything based on ActiveRecord without reasonably expensive (in dev time, anyway) setup. What am I missing?

I don't mean this is expensive...

  foo = foos(:my_foo_fixture)

...I mean a zillion lines of pure clutter, building object after object and glueing them all together just the right way. That's expensive.

Fixtures are among the systems that keep object models easy to whip out and use.

Why not mock/stub model objects instead? I don't see a single benefit from using fixtures, except that the setup expense is shifted from the developer (lots of mocks) to the computer (excessive DB access resulting in *slow* tests -- see Asynchronous Unit Testing antipattern). Is there a third way that I'm missing?

Better the computer is slow than the developer. That's orders of magnitude difference there.

If your tests get too slow, install CruiseControl.rb for a build server.

<Yikes!>

ok that was some intense stuff. I dint understand a lot of stuff going around because, as established before, I dont have experience writing tests. But the following are the things Im taking out of this discussion.

- jump in the dirt. Do TDD for your existing app by starting all over again if you have to. Thats the only way to go (?) / thats the best way to go to become a better programmer (?)

- i dont *absolutely* need any external tools besides test::unit. I probably would use the right tools if i ever felt the need for them in the first place

- use fixtures when I have to test something that uses complex associations between models. especially when the alternative is to spend a lot of time and brain on mocking/stubbing them instead. (I have to mention I dont know the difference/similarities/functions of mocking and stubbing completely)

- i dont have any client documentation to show for these tests. theyre only for the sake of testing my code itself. So ill skip over RSpec and Cucumber (until i feel a need for them)

- test code keeps evolving. I need to optimize test code as much (or more ?) as i optimize dev code. and tests breaking out of nowhere will be a way of life (?)

i am going to be adding features to the app in between too. anything I have to keep in mind while doing that? when do I start on integration and functional tests? Also, any good articles that could help me gain some perspective on the task i have ahead of me?

my 2 cents worth.. i personally like the feel autotest gives. especially for TDD. but hey.. no experience. only tryouts and screencasts.

Please DO let me know if I have taken away the right things from here *to get started* with writing tests for my existing app. I hope this discussion goes further and provides insights for many more in my place.

Thanks Fernando, Marnen, Phlip, Brandon and Hans :slight_smile:

my 2 cents worth.. i personally like the feel autotest gives. especially for TDD. but hey.. no experience. only tryouts and screencasts.

Yeah autotest definitely looks cool in $9 screencasts, but when it comes to developing a real application that has a few more features than a blog or a weather forecast parser, you will eventually turn autospec off.

As you said, the best solution is to get started now!

<Yikes!>

ok that was some intense stuff. I dint understand a lot of stuff going around because, as established before, I dont have experience writing tests. But the following are the things Im taking out of this discussion.

- jump in the dirt. Do TDD for your existing app by starting all over again if you have to. Thats the only way to go (?) / thats the best way to go to become a better programmer (?)

I don't think that this is a good idea at all. Definitely start testing immediately but I wouldn't rewrite the app at all. For every bug fix and change, make sure you write tests for the functionality you are working on (in a TDD/BDD way - before changing the code.) Jim Wierich did an excellend talk at Scotland on Rails about Comment Driven Development which, if I can summarise it accurately, is as follows: When changing/bug fixing existing code 1. Comment out the code in question 2. Write tests on how the code should work 3. Only uncomment the code that makes the test pass Repeat 2 & 3 until you have the code completely covered in tests 4. Write a test for the new feature/bug fix (if not already fixed by now) 5. Write the new feature/bug fix Done!

If you do this whenever you work on existing code, you'll grow the test coverage of the app over time.

- use fixtures when I have to test something that uses complex associations between models. especially when the alternative is to spend a lot of time and brain on mocking/stubbing them instead. (I have to mention I dont know the difference/similarities/functions of mocking and stubbing completely)

I still wouldn't use fixtures. I work with factories because then you can put together the complex associations and data needed for just the question at hand. I have recently started creating a test library for very complex applications that will build up a complex set of data via TestData.load_data type calls. I do this so that I only load up the data for those areas where the tests need them and not on every test.

- i dont have any client documentation to show for these tests. theyre only for the sake of testing my code itself. So ill skip over RSpec and Cucumber (until i feel a need for them)

Cucumber is not just for client documentation but does end-to-end or full-stack testing which is useful for getting as-close-as-the-client-experience testing

i am going to be adding features to the app in between too. anything I have to keep in mind while doing that? when do I start on integration and functional tests? Also, any good articles that could help me gain some perspective on the task i have ahead of me?

This I covered above. Start your testing with the new features (Another reason not to re-write) Include all the testing you want on a per-feature basis.

my 2 cents worth.. i personally like the feel autotest gives. especially for TDD. but hey.. no experience. only tryouts and screencasts.

I have no problem with autotest running on large projects as I find that when it starts running the full suite, I'm busy writing the next test/spec. When working with a failing test, autotest only re-runs the failing test anyway.

Andrew Timberlake http://ramblingsonrails.com http://www.linkedin.com/in/andrewtimberlake

"I have never let my schooling interfere with my education" - Mark Twain

@Marnen,

Thanks for the responses to all my concerns. And I will take your advice and give RSpec a go too. It definitely is more appealing to the eyes at least on the test method name level (which is how much i know of RSpec +/ test::unit :slight_smile: )

Huh?

I meant that once i get into writing tests, ill probably know what tools i need if at all i need them.

@Fernando,

good point well made :slight_smile: ... I have it installed anyway so Ill go along with it until it starts getting in my way :slight_smile:

@Andrew,

I don't think that this is a good idea at all. Definitely start testing immediately but I wouldn't rewrite the app at all.

That is sweet music to my lazy ears :D. The whole reason ive conveniently ignored writing tests for so long is because its daunting. Rewriting the whole app and doing it the TDD way makes it even more daunting! I must say though that I realize rewriting with TDD is probably gonna do more good than covering my code with tests now. It will make me revisit my app and clarify requirements and functionality and help me understand my app itself a whole lot better overall. But for now, I think im gonna go with writing tests bitwise, covering existing code. If i feel insecure about it at some point, maybe ill rewrite with TDD to give the app a more solid foundation. Ive spent months on this app and rewriting with TDD is just too much added time investment.

The Comment Driven Development part is very close to my situation right now. Its an approach that I probably wouldve taken naturally out of necessity rather than in order to follow a technique. :slight_smile: Thanks a lot for mentioning that. I will look it up in detail.

Cucumber is not just for client documentation but does end-to-end or full-stack testing which is useful for getting as-close-as-the-client-experience testing

That is actually a good point. But when do I start writing full stack tests? or integration and functional tests too for that matter?

Does one always start writing tests with unit tests and work through functional, integration and then full-stack-tests? Isnt that like going from backend to frontend? Would that be the right approach for ANY kind of application? Even if its largely user centric and has got very little magic going on in the models?