Tests Are Overhyped - <AUTHOR> http://sturgill.github.io/2013/04/15/tests-are-overhyped/ <comment><USER3> My experience is that you can write an essay like this about any development practice. You can cite your experience ignoring it, you can say some nice things about the importance of experience and priorities and managing trade- offs, and you can satirize people who are dogmatic to the point of becoming cult-zombies.

It appears as if such an essay providing great advice. But it it?

What is the reproducible, objective process or behaviour this essay is advocating? If I give this essay to five teams and then look at what they are doing to follow its advice, will they all be doing the same thing? What results does this essay suggest we will obtain from following its advice? How can we be sure it will be better than the results we would obtain from mindlessly chaining ourselves to the red/green light?

For better or for worse, the red/green light protocol is specific. As such, it can be criticized. A specific protocol has edge cases. You can argue slippery slopes. It's a stationary target. Whereas, vague and nonspecific generalities are more difficult to criticize. There are no details, so how does one identify edge cases?

It's great to hear about this one specific anecdote. beyond that, what am I supposed to walk away with besides the knowledge that slavishly following a process can be bad?

<comment><USER4> On the other side:

Today I was working with a new library. I wrote a 30 line sample program just to make sure I understood the library semantics, and that it would at least do what I thought in a situation similar to the actual code base.

I called over another developer to sanity check my thinking, and he spent 10 minutes going on how I should have just written tests for it in our codebase instead.

He would not take any of these as valid discussion points:

* I spent nearly 7 minutes on my sample code, writing tests including the appropriate mocks for our codebase would have taken 70.

* I didn't even know we would be moving forward with that library, why start integrating it into our infrastructure?

* I'll write tests of our code using the library, when we figure out what the thing we're building actually does.

* I would have to write that same sample program before I can even write tests, to know how to use the library.

I do know now not to include that guy in my thinking process ever again, if tests aren't perfect, I will lose any time including someone might gain by dealing with his TDD is my holy saviour rants about how I should learn.

Worst part: this guy takes days to write "tested" code that still doesn't actually do what it is supposed to.

<comment><USER5> You did a spike.

It's ok to be untested for discovery. Even in TDD.

In pure TDD you would be supposed to throw it away afterwards and redo it clean (with learnings) based on test-first.

<comment><USER6> And that is exactly what is wrong with TDD - the sheer dogma involved in a insane statement like that. Throw out all the code - tests weren't written first!

It doesn't seem to matter much that the end result will be the same if you write up some tests for that code, or if you throw the code out, write tests, then just write the same code again. If the tests didn't come first, it's not TDD, and now we can't follow some holy procedure.

Pure madness and everything that is wrong with TDD is summed up in that simple statement: "In TDD you would throw it away and redo it".

<comment><USER7> In any development, you probably want to throw away your exploratory prototyping - that's not TDD specific. I've seen/heard "write it; throw it away; rewrite it" attributed to Knuth on several occasions, but I'm not finding the original source.

<comment><USER8> <http://c2.com/cgi/wiki?PlanToThrowOneAway>

</comment></comment></comment></comment></comment></comment><comment><USER9> Tests for software development == Crimes for political agenda.

This is one of those issues you are supposed to lie about.

Tests are like crime in politics -- no politician is going to say "I am soft on crime, I think we should reduce sentences." So crazier and crazier laws are created. Mandatory minimum sentences for possessing small amounts of drugs, all kind of craziness. People know it is crazy, but nobody is capable of speaking up and remain standing.

Same thing with tests. Nobody can say "fuck it, stop writing tests, the customer will never run this code, or this is too fucking obvious, test stuff that matters". That is considered irresponsible. Everyone is supposed to worry about not having enough tests.

Now there a subtle difference and that is when it comes to shipping on a schedule and in many companies tests are ignored -- BUT silently. Everyone loves talking about tests but try and tell you boss you spent 2 weeks on adding tests to your code. They might not like. Try to double the time you promise to do a feature by saying I need to write tests for it. Or if you are given free rein try saying I won't do all the new awesome features, I'll write more tests -- it will be approved probably but everyone in the end will praise the guy who chose to work on and deliver features -- even though they might be completely buggy and unusable. So that is the other side if you will.

<comment><USER10> > Same thing with tests. Nobody can say "fuck it, stop writing tests, the > customer will never run this code, or this is too fucking obvious, test > stuff that matters". That is considered irresponsible. Everyone is supposed > to worry about not having enough tests.

I don't know about everyone else, but I definitely worry about having too many tests. For every test I write, I have to weigh how useful the test is versus how likely it is that the thing it is testing will change. If its usefulness is overshadowed by the likelihood that it will be a burden later on, it does not get written.

<comment><USER11> Apply the same thinking to the feature code you write as well.

<comment><USER10> Oh, that threshold is even higher.

</comment></comment></comment></comment><comment><USER12> _tl;dr: Tests are overhyped because we once wrote tests that became irrelevant when the thing we were testing changed_

Really? I mean, tests _might_ be overhyped, but so far it looks like the author draws incredibly general conclusions from some isolated incident. Why did the tests become irrelevant? Is their scoring algorithm now doing something completely different? Do they now have different use cases? Were they hard-coding scores when the actual thing that matters was, say, the ordering of the things they score?

> _Only test what needs to be tested_

well, thanks for the helpful advice :) Care to share what, in your opinion, needs to be tested?

<comment><USER13> I've heard this saying: "Test until fear turns to boredom." Then you need to make sure you get bored at a properly calibrated rate (i.e. not too soon given your business' criticality, not too late given your need to move quickly). For example, if a lot of expensive bugs during final cause analysis are found to be preventable via unit tests, then your calibration is probably tuned to being bored too quickly.

<comment><USER14> This is a great line. I think it goes deeper though, in that after doing this for a while, if it hurts, you are probably doing it wrong. Writing code with too little tests hurts, because you are scared shitless. Writing code with too many tests hurts, because you are performing a religious rite not actually building something useful.

The trouble is that you have to do this for a while to get to the point where you can both feel and recognize pain, or the lack thereof.

</comment></comment></comment><comment><USER15> In my admittedly limited experience, unit tests are way overhyped, especially when things like mocking are brought into the mix. It's easy to end up with a test that is not about correctness, but "did line 1 get called, did line 2 get called, etc.". Then you change the implementation, and 20% of your test cases break. That's not to say that they are valueless, but that I think unit tests should be used pretty sparingly.

Where I've found a ton of value has been in writing almost artificial- intelligence driven integration tests. Write a bot that uses your service in way, as fast as possible. Run fifty of these bots simultaneously, and see what happens. Then have some way to validate state at various points (either by tallying the bots actions, or sanity checks). Bugs will come fallout out of the sky. Then, in the future, when you get a bug, the challenge becomes to update the integration test bots behavior so that they (preferably quickly) can reproduce the bug.

I mean, I think that this is dependent on the domain of your software, but I think it's a good strategy for many areas.

<comment><USER16> If we're only using unit tests to see if line N gets called, I think we're doing it wrong. Instead, we want to use unit tests to tell us if the answer we get is correct -- while exercising line N.

e.g.: def test_foo(self): result = get_foo(bar=12) self.assertEquals(result.category, 'FOO') self.assertEquals(result.name, 'my- foo-12') self.assertEquals(result.unit_price, 97.12)

This lets you verify that this particular branch (when bar=12) is executed, and that your results are as you expect. If you change some of the underlying calculations, things can break (as you get different answers), but then you at least have a test that lets you ensure that changing the answers is what you want to do. Sometimes, you want to change the way you calculate something and get the same answer, after all.

<comment><USER15> So the question is, what if bar = 12 means "retrieve foo with ID 12 from the FooService", and we want to make sure that get_foo does something sensible when the server returns an error code.

So what do you do? Typically one writes a mocked up service that returns the expected results, pass it in somehow, and write your tests like you did above. So if you have a lot of services, you end up doing what I said - testing lines of code. Here you're testing that FooService gets called. If it also called BarService, you'd be testing that BarService gets called. And so on.

But then later, we decide that FooService is no good - we want, nay demand - <USER2> FooService2, with a new API. However, get_foo is to behave the same. So what now? Only one choice - update all of the tests to have a mocked up FooService2.

As the code base grows, I find this becomes annoying to maintain (although to some extent a necessary evil, of course).

The alternative I'm saying is that instead of spending a ton of energy unit testing get_foo, hammer on it and write good state validators. Your unit test shows that get_foo for bar = 12 returns a unit_price of 97.12. Great, but I don't think that's as interesting as building a fake database (so we know what the expected returns are), and then making 50,000 requests per second with random data for 12 hours, and then through runtime assertions and as a post- process validating that the service actually did what it was supposed to.

<comment><USER17> Interesting? Testing isn't about programmer enjoyment, it is about correctness.

A 12 hour stress test is going to catch different things than a unit test. A simple suite of regression tests can be automatically run by a continuous integration tool to flag if the build is broken and alert the dev/team so things can be fixed quickly.

In this example it seems you are thinking of writing tests as a separate step from writing the code, which is part of why it seems like a chore. Make small changes, update the tests until everything passes & new code is exercised, commit, repeat. (Or if you are better disciplined than I, update your tests first and then write code until tests pass, repeat) Monster refactors, while sometimes necessary, are best avoided when possible.

<comment><USER15> What I meant by interesting is that they tell me more about the health of the system, not that they're more interesting to write.

Suppose there's a race condition in some library that you're using. No unit test in the world is going to catch that. Now, unit tests certainly have their place - but my point is that from what I have seen, unit tests catch the boring bugs, while integration tests catch the interesting ones(by interesting here I mean obscure or subtle - deadlocks, invalid state, etc), while at the same time inferring the boring bugs (ie. add(5, 3) returns 7 instead of 8), so that hour for hour, especially with limited resources (ie. a small startup), integration testing has the potential to give you a lot more value.

<comment><USER17> That makes much more sense!

However I would still add that simple suite of regression tests (in my CRUD app these are almost entirely integration tests), often speed up development by more than the time it takes to write the tests in the first place. So to say a startup doesn't have time for them seems shortsighted.

</comment></comment></comment></comment></comment></comment><comment><USER18> I find it interesting that the premise for this entire diatribe is that once some code was written, a pivot was made, and a number of tests then had to be thrown away (or reworked, or re-factored?).

Recently I had a code base where we decided that due to a new delightful feature our customers were going to be quite pleased with we would need to switch out our old queuing system for a new one. In doing so well more than half of our huge test suite turned red. This told us two important things 1) that the queuing system touched a lot of areas of code we needed to think about and 2) where in the code the queuing system had touch points.

Ultimately we were able to put in the new queuing system, fix the areas that were broken by the change, and have the confidence at the end of the process that we had not broken any of the areas of the code that were previously under test. (This does not mean that our code was bug free of course, only that the areas under test were still working in the prescribed way, but that is a discussion for a different article.)

I believe that this would have taken a team of people weeks to do previously. I was confident that the change was ready after only 3 days with 2 developers. I would not trade my tests. There is a cost associated with everything, but I believe tests are the least costly way to get highly confident software built.

</comment><comment><USER19> Get halfway through a project, realize you have to make a big change, then make it. Without tests i'll guarantee you'll watch your stability plummet. With tests, you might just go home at 5 pm. Alternatively don't make the change, and deal with a problem in your design. I've seen it more than a few times to have become convinced that there's a lot of value when striving to cover as much of your code as you can.

<comment><USER20> If you have a statically-typed language - and it doesn't even have to be a good one, with C++ being fine, in my experience - then making such changes is usually a case of making the change, or perhaps removing the bit of code you intend to change, compiling, and seeing what happens.

What happens is usually that you have 14,000,000 compile errors. Well, congratulations! That's the difficult part over. Now it's time to relax! Start at error 1, and fix it. Repeat. Every now and again, build. Once it builds again, it will usually work; if not, it's always something quite simple. If you have enough asserts in your code, then you can be doubly confident that there's nothing wrong with the new code.

I've had good success with this approach, for all sorts of changes, large and small. I've given up being surprised when the result just builds and runs.

I have no real idea, how you would do this reliably in a large program written in something like python. Sure, you'd fix up your tests easily enough... but then what? Don't you have a program to maintain as well? :)

Jonathan Blow wrote about this years ago: <http://lerp.org/notes_4/index.html>

<comment><USER19> Its rarely the case that you can fix 100 errors, and everything is working just 100%. There's often one corner case that works just a little bit differently.

<comment><USER21> Depends on the power of the type system. In languages with stronger / more expressive type systems than C++ (e.g. Haskell or Scala) the compiler catches really a huge amount of possible problems. The downside is it sometimes catches non-problems, too.

> There's often one corner case that works just a little bit differently.

You might just as well miss that one corner case in your test suite. This is the problem with tests - you can never be sure.

</comment></comment></comment></comment><comment><USER22> Care to comment on your experience with larger code bases? The content of your post seems short-sighted, and there's an exponential function of complexity increase as LOC and developer headcount both go up.

You're right people pay for features, but lagging a little at the beginning to establish good TDD culture pays off in spades later on. Shipping product is something you have to do continuously, and you arguably create more value as time goes on, so ensuring you can continue to ship product in a timely manner is a great thing for organizations.

<comment><USER23> I'm not the original poster, but I find that integration tests have a far larger payoff than unit tests, in general. A good release process that tests differences in behavior between a test system and the current version of the service in production is also valuable.

Being able to test that the whole system works as intended gives a better return on investment, in my experience, than testing small bits in isolation. The errors are, often as not, in the glue between the small bits.

<comment><USER24> The main advantage I've found from testing little bits in isolation is that it tells you a lot more about where exactly the bug is. However, there's no reason why you need to write them in advance to get this benefit.

The general workflow I've grown fond of is to write mostly higher-level tests that test the system as a whole, and then only write fiddly unit tests when there actually is a bug to fix. Those unit tests then stick around, but I don't feel bad about blowing them away without replacing them if the thing being tested changes significantly enough to make them useless.

</comment></comment></comment><comment><USER25> Behavior/test-driven development needs all the hype it can get. There are so many developers, even entire software development subcommunities (I'm looking at you, video game developers) who haven't written a single test in their lives and don't understand its value.

Yes, it is time-consuming and invisible to your customers, but I imagine so is setting up a frame for a house instead of just stacking bricks. The structure, flexibility and peace of mind you get from a comprehensive test suite pays off when you have a 50-brick tall structure to put a roof on.

<comment><USER26> In my experience test-driven development is not time consuming, even for small developments. I don't think we even need to say things like "yes it takes time now but it will pay off later". I have found that it saves time right from the beginning. It seems other people have a similar experience : [http://blog.8thlight.com/uncle- bob/2013/03/11/TheFrenziedPan...](http://blog.8thlight.com/uncle- bob/2013/03/11/TheFrenziedPanicOfRushing.html)

</comment></comment><comment><USER27> I'm not necessarily disagreeing with the author, but I think if you are going to 'do agile', especially in a breaky language like C++, you need to do tests. Lots.

The current shop I'm at is maintaining a huge code base, parts of which go back 20 years. Because test coverage is so low, there is a real reluctance to refactor.

The first thing I did when I started here was to clean up the code, renaming miss-named variables to get it in line with the coding standard, adding autopointers here and there to head off memory leaks. By gosh, I nearly got fired.

If you are going to fearlessly edit your codebase, you need to know that regressions are going to be caught. You need automated testing.

</comment><comment><USER28> "We wrote the first scoring algorithm at Goalee based on the red-green light. Within a couple of weeks we made our first algorithmic change, and made several quick fix releases to update the scoring methods in the following weeks. By the end of the month, a whole section of our testing suite was almost completely worthless. In a world where cash is king, I wouldn't mind having those dollars back."

What I don't understand about comments like this is that a whole section of your code, _both_ runtime / deliverable code and test code had become worthless. But, you only seem to view the discarded test code as wasted effort. Either the tests have value or they don't. And, if you write tests, and then discard the code they test, you'll likely also discard the tests. But, that doesn't change whether or not the tests had value, nor whether the new tests that you'll write for the new code have value.

<comment><USER29> > What I don't understand about comments like this is that a whole section of > your code, both runtime / deliverable code and test code had become > worthless

Not so. The code demonstrated that the first algorithm wasn't good enough and provided the experience needed to write the second one. The tests (hopefully) made the first algorithm's code maintainable, but it turns out there was no need to maintain it.

</comment></comment><comment> ryan-allen I think the hype of tests is driven by agencies that charge by the hour. One thing I have noticed is that on an existing system especially, you can put a very inexperienced developer down and instruct them to 'write tests for untested functionality', and do so but produce neligible value.

The same thing with green fields development. I've seen steaming piles of shit with huge test suites. Absolutely zero insight into the problem. No craftmanship at all, nothing interesting about the application. But a set of tests.

It's like the suite is proof enough that there was a job well done. I fear that a lot of development is devolving into nothing more than superstition and hype, backed up by agencies that like to bill a lot and amateurs who need a justification for their timelines and ineptitude.

</comment><comment><USER30> Amen! I run <https://circleci.com>, where we make all of our money by actually running tests for people, and I still believe this. The goal of your software is to achieve goals, typically business goals. Often the software itself is already one or two steps removed from the value provided to customers. Tests are an extra step removed at least.

I wrote a similar piece here: <http://blog.circleci.com/testing-is-bullshit/>

<comment><USER11> Of you don't care whether your CI tool works, I won't care either, because I won't use it.

<comment><USER30> Perhaps I missed where I said I didn't care - where did you see that?

</comment></comment></comment><comment><USER31> Tests are not overhyped. They are under-understood. Unit tests are not regression tests are not integration tests. I've encountered tons of teams that don't seem to understand this.

Unit tests are more than any other factor a design tool. Like any other design tool (uml, specification, etc), when the design needs to change, you throw them out. If it takes longer to design a system with unit tests than without them 1 of 2 things is true 1) you should not write unit tests 2) you should learn how to write unit tests.

</comment><comment><USER32> In total agreement with the OP.

I think it just goes to the way human beings handle original ideas, first they fight them, then they embrace them, then they take them to ridiculous extremes as they try to substitute rules for common sense in applying them.

You can see it in politics, religion and almost any really popular area of human endeavor.

Testing falls in the same category, I have had interviewers look me in the eye and in all seriousness, declare that developers who don't write tests for their code should be fired, or that their test suites cannot drop below x% of code coverage. Dogma is a horrible thing to afflict software teams, whether it is pair programming, or mandatory code reviews, if there are no exceptions to the rule or situations where you don't have to apply it, its probably a bullshit rule IMO.

Me, I like to ship shit, and I like to look at tests as a way to help me ship shit faster, because the less time I spend fixing regressions the more time I can spend actually getting more code/features out that door.

So my only metric for writing tests is this ... "is this going to help (me or a team member) not break something months from now, when I change code somewhere else".

I honestly don't care about anything else.

<comment><USER11> Tests certainly interfere with your ability to ship shit.

</comment></comment><comment><USER33> I use a strongly typed functional language, so I don't need to write tests. If my code compiles, it's correct.

<comment><USER34> Poe's law applies here.

<comment><USER26> Thanks I didn't know about Poe's law. My first thought was that it was a joke and a rather good one, but then seeing replies taking it seriously I started to doubt :)

</comment></comment></comment><comment><USER35> I have a long experience in enterprise software and I agree with the premise.

There are two kinds of test units: workflow and functional.

1 - Workflow test units are a waste of time because no single test unit stays valid when there is a change. In other words, whenever we added/removed steps in the workflow, 99% of the time we have to change the test unit to fit that new workflow which breaks the concept of "write once, test all the time" concept. In my experience, having proactive developers who test areas around the workflow that they changed is much faster and reliable.

2 - Functional test units are great. They test one function that needs certain parameters and is expected to spit a certain output i.e function to calculate dollar amounts or do any king of mathematical operations. However, these functions tends to stay unchanged during the lifetime of a project. Therefore, the test units are rarely run.

From my experience workflow changes/bugs represent 80% of the problems we face in enterprise software. Functional changes/bug are rare and can be detected quickly.

This is why I agree with the author premise that unit testing is overhyped.

</comment><comment><USER36> I tended to do API-centric functional testing (does it spew JSON with the structure and data I expect?), and found it to be a time-saver in that it was faster to write a test and re-run it to check output than to manually use the web app or make the calls myself.

However if the test exceeded this cost/benefit metric where it wasn't really helping me get the feature written, out the window it went.

Helped when I went to refactor/fix fairly major chunks of the backend as all those tests from back when I did initial development were still there. It wasn't really "test first" because I didn't know what to test for until the basics of the API endpoint were in place.

This was Python if it matters (default unittest2). I do mostly Clojure when I have the choice lately.

It's not even really a matter of "does it need tested?", although you should be asking that question and building up the coverage for the critical bits.

For me it was a question of, "is this going to save me time/sanity?"

I advocated tests to the other engineers at my startup only when they were experiencing regressions/repeat bugs. I left them alone about the lack of test discipline otherwise.

My Clojure code tends to "just work" (after I'm done experiencing insanity and disconnection from reality in my REPL) to the degree that I mostly write tests when I'm making a library or touching somebody else's Git repo.

This is all fitting though. I use Clojure instead of Haskell precisely because I'm impatient, lazy, etc. Would kill for a "quickcheck" for Clojure though.

This whole debate has a whiff of excluded middle (we have 3 UND ONLY 3 TESTS <\---> TDD ALL THE TIME!), not to speak of people not mentioning how tests can simply...save time sometimes.

</comment><comment><USER37> Funnily enough what the article describes is almost the perfect case for testing: "We wrote the first scoring algorithm...based on the red-green light." This sounds like it describes some heuristic weighting, which couldn't have been solved by types, but reasonable tests _would_ have shown if the new algorithm weighted some special cases higher or lower than it should.

The problem with an heuristic weight though, is that it's an heuristic, judged against other heuristics by taste not proof.

The obvious testing approach, ensuring that the score for each test case retains the same order as you tweak the algorithm - is overtesting. You don't care about this total order; you more likely care about ordering of _classes_ of things, rather than ordering _within_ those classes; or simply that 'likely' cases follow an order. Hence, you hit far too many test failures.

I'd agree that it's possible to overtest in general, but it's so easy to overtest heuristics that it needs called out as a special case, and it sounds like the problem here.

</comment><comment><USER21> No amount of tests can help you if don't know how to solve the problem. And the better you know how to solve the problem the less tests you really need. ;)

Old, but quite relevant: [http://ravimohan.blogspot.com/2007/04/learning-from- sudoku-s...](http://ravimohan.blogspot.com/2007/04/learning-from-sudoku- solvers.html)

Some sane amount of testing is good. However, I'm not very convinced writing tests first is a good idea. I saw a few programmers practicing this and when writing code they often concentrated too much on just passing the damn test- cases instead of really solving the problem in a generic way. Their code looked like a set of if-then cases patched one over another. Therefore, if they missed an important case in their testing suite, they had 99% chances for a bug. Once I ended up writing a separate, more generic implementation _to validate the test suite_. And it turned out there were a few missed/wrong cases in the test suite.

</comment><comment><USER38> Seeing how many people agree with the post I am left wondering who the commenters on HN are. With a large code base and actual customers, comprehensive unit testing is by far the most cost effective way to create and maintain software. This is not being dogmatique, it's the shared experience of the majority of established software engineering firms. In the case of my company, we experienced so much growing pains that our productivity almost came down to zero before we switched to TDD. Many developers in our group were skeptics (including me) but today you won't find one of us arguing for less testing.

The kind of large pivot that the author refers to is only possible when you don't have established customers and you have a minimal product. You may as well call it prototyping. And prototyping with or without tests is indeed more a matter of taste than effectiveness.

</comment><comment><USER39> This post is over-hyped: "the cool guy who ships products and applies to cool startups, but they only hire super talented and passionate engineers."

\---

The text above is just like the blog post: is unfounded and purely based on personal opinions.

Having a strong test culture in a company of any size is important for a number of reasons, and all of them are founded by both books and articles, but also by AMAZING products.

An engineer who has talent in writing readable and well structured tests is also someone who has a special skill in: creating robust systems, reverse- engineering existing systems and therefore good at being hired by a startup that has NO or very little test culture, which end up being hired by a company that has code that is buggy, error prone, coupled and hard to maintain, so that he can apply all this knowledge to clear crap written by people who doesn't like tests

</comment><comment><USER40> An ex-colleague of mine used to put it well in saying: "It's best to be pragmatic rather than dogmatic while testing and pair programming."

<comment><USER41> I think that can be easily generalized to: "It's best to be pragmatic rather than dogmatic."

<comment><USER42> It is pragmatic to be dogmatic in a context where there is a a temptation to cut corners which will result in non-obvious, severe negative consequences.

<comment><USER43> Ahh, but is it not dogmatic to assert a statement is always true for one class of situation? Accepting imperfection, are we not pragmatists? 道可道非常道 (The Tao that can be told is not the eternal Tao) 名可名非常名 (The name that can be named is not the eternal name.)

</comment></comment></comment></comment><comment><USER44> So because his particular tool (or use of a tool) adds inconvenience or overhead means the entire concept is bunk? Don't confuse the thing with the concept.

Tests are double checking your work. ("Yup. That condition I said would be true still is!"). The tighter and more lightweight we can get that feedback loop going the better out output and the more confident in our work we'll be.

</comment><comment><USER45> I find unit tests written after the fact to be pointless. TDD makes a lot of sense because it forces you to think about how you are going to write your code. I like that. If you're writing tests after the fact, integration tests have a much more satisfying finish, and I can't imagine going without them (unless they are painful to implement)

</comment><comment><USER46> >>> We wrote the first scoring algorithm at Goalee based on the red-green light. Within a couple of weeks we made our first algorithmic change,

I think he actually mens an specification change. Tests would help you refactor in case you want to change the algorithm against the same specification.

But yeah, is a flawed metric so it shouldn't be put on a pedestal.

</comment><comment><USER47> _[I]f any portion of your site changes (pivot, any one?) you're now in a position of having to rewrite large portions of your tests. And the larger the pivot, the more useless your old testing becomes._

I'm under the impression that the tests are written first. If you are writing new code, then first there's a (failing) test, then there is the new code. If you are altering existing code, then pivot or not if something breaks you need to see if the reason is broken code or an inappropriate test, and you fix it before moving on.

In any event this should be a gradual process. How common is it that large slabs of code gets changed while ignoring failing tests, or large slabs of new code gets added while skipping the tests?

Is it that TDD is, in actual practice, unsustainable, or is the problem with not adhering to TDD? Or something else altogether?

</comment><comment><USER48> I don't know what to do with tests, to be honest. I am a very inexperienced developer, and the general sentiment is "knowing what to test is a learned skill"

 _damn._

I could use some opinions actually. The current workplace arguments about what we should or shouldn't test go like this:

       "We write tests to establish specifications, then we write code to meet
        those specifications. We should have tests covering every aspect of the
        system as a way to assert that things are meeting the designed specs."

       "but our model objects have allot of tedious detail. Why should we write
        tests about what the name field can and can't accept? It's a max length of
        32, that's it. Asserting that the constraint fails is beyond tedious and a
        waste of our time. Most of the code we'd be testing is auto-generated. Are
        we running tests on our framework or our code?"

       "Some of this does seem like a waste of time, but what about when
        someone changes something as part of the development cycle? eg.
        Someone needs to remove validation from the name field to test other
        parts of the systems behavior with an overly large name. If we had a
        complete testing system in place it would alert us that the model isn't
        meeting the spec. We've already had instance where temporary code to
        bypass authorization was accidentally pushed to the develop branch."

On one end of the spectrum there is this base level of tests that are actually _REALLY_ useful when developing features. Doing simple testing has helped me catch off by one errors and other kinds of bugs, I can stand by my code confidently. These kinds of ad-hoc in development tests don't cover everything, but they're useful. They're like a substitute for step through debugging to verify code.

On the other, I don't know how big of an issue bug regressions will be, we've heard other developers suffering for lack of a solid testing base to detect problems. Without a full battery of tests asserting everything we know about the spec, there's no way we will catch many regressions.

HN what do you think?

<comment><USER49> > I don't know what to do with tests, to be honest. ... HN what do you think?

Well, since you asked!

The most valuable tests in any system is functional tests. Unfortunately most tests are unit tests that give little value.

Here's something that I encountered recently in the wild. Imagine a situation like this, a calculation process with three distint black boxes of code.

Block A - Pull data from 3rd party source

Block B - Distribute data to individual nodes (multi-threaded environment)

Block C - Individual nodes processing data

Each one of these blocks is around fifty thousand lines of code, each one of these blocks has hundreds if not thousands of unit tests. Every line of code is tested by a unit test. Yet there is a very real and dangerous bug in the system.

Why? Because the object passed from B-C has a transient variable and when it is serialized and deserialized that value is lost and reverted to the default value. Now most places leave this value as the default, so it's only one out of a thousand customers that have this problem, but when they do it's a huge problem.

Functional tests is the process of saying "I put meat/spices on this side and sausage comes out the other" it doesn't try to determine the RPM of the grinder, the number of bolts, the rotation of the gears, or the type of metal used to build the sausage-maker. It is simply the process of determining that meat becomes sausage. Functional tests have high value and are absolutely worth knowing.

In most CRUD applications Unit Tests generally wind up testing that the universe still exists as expected (true is still equal to true, zero is not one, and a null value is not the same a string, oh happy days the system works!).

That's not always the case. If you are working on something that is more advanced, say something that should measure the chance a hurricane might knock down a given 3d model you'll wind up having a huge stack of unit tests, and these will be very valuable. More often than not you'll know they are valuable as they'll be spent proving the science behind the application, and not simply that the application 'does something'.

<comment><USER48> Thats good advice, thanks.

That bug with the transient variable. You could only would really catch that if you had e2e or integration tests covering a majority of the code in your application, right? Even then, only if you were to persist the data, read the data back out, then again run more tests on it.

I accept testing isn't a silver bullet, but ouch.

As a general strategy, it sounds like it's better to run your higher level tests as a gauntlet (feeding the result of test one into test two) then with tightly controlled inputs (using explicit data for each test).

</comment></comment></comment><comment><USER50> Even though I can sympathize with the tone of the OP, I think his argument cannot be generalized. Consider the following scenarios:

A one-person engineering team. This is some 20-something working on a start-up in his parents' garage or the 40-something code hobbyist out there that likes writing fun little apps every now and then. I would argue that there is virtually no need for testing unless you're either bad at writing code or inexperienced. I've written dozens of applications (in various languages) and once you get into the swing of things, you don't need TDD to actually "test." Debugging/edge cases/etc. just becomes a natural process of writing code.

A two-person engineering team. This is a secondary stage in every start-up -- sometimes, start-ups even are founded by two engineers. Here is where TDD starts being important. I may be an expert coder, but if my partner isn't that great (or if our code doesn't work well together), not testing can be a huge nightmare. But the impact is still relatively small. Bugs are easy to spot as both engineers are (or at least should be) incredibly familiar with the _entire_ codebase.

Three-person to 10-person engineering team. Here is where things get really tricky and TDD becomes integral to meeting deadlines and actually, you know, putting out products. You've got Jim working on some financial stuff while Bob is optimizing some JPA code. At the same time, Susan is implementing a couple of new features. Having a test suite ensures that behavior will remain predictable given non-centralized iterations. Without TDD, large teams would be fixing bugs more than they would be writing code (most teams probably do that anyway -- not that it's a good thing).

10+ people; open source projects, etc. When you have more than 10 people working on a project, I think that TDD is simply a necessity. There are simply too many moving parts. Without a cohesive test suite, having this many people mess around with code will undoubtedly break stuff.

Ironically, I think that small teams put too much emphasis on TDD, whereas teams in larger companies (AT&T and IBM, for example) put too little.

</comment><comment><USER51> There seems to be a sense that writing tests slows you down. And that is understandable. However, I find that tests helps me move in small steps and provide a feedback loop that helps me stay in a groove moving towards the finish line. And they help me move faster. I think we as developers need to continually learn how to write better tests that provide deeper value and allow us to move more quickly.

I find that when testing is tough it is often that the underlying design is deficient. And tests shine a light on code and design smells. Discarding tests could be valuable if the tests have outlived their value. It might also be the case that excessive test maintenance is telling you something about your production code.

</comment><comment><USER52> My general rule:

If you are planning on some sort of reuse (API, library, protocol, etc) a test spec is a _very_ good idea if only to hash out practical use of the interface and identify caveats in the interface spec. Once released, the test spec is great for answering the question "did I accidentally break something that used to work?" thus vastly speeding up the bug-fix process for underlying components or widely used components.

If you are writing an end-user app, or a service that will be used non- programmatically (such as a GUI or web app), then a test spec is not required and probably a waste of time as things will likely change too quickly.

</comment><comment><USER53> I'm sorry, but I've seen both sides of the coin here and think that in the right situations, having a suite of automated-tests to give you confidence in an application is invaluable. Especially when you consider the alternative, which is hours wasted debugging. Sure writing tests can be hard, but it will make you write better, more modular code.

If you really do need to just get something out the door that quick, then you should just be prepared to accept the consequences of no tests, or put some in later for maintenance sake.

</comment><comment><USER54> Depending on the context, I fully agree (most stuff here is about web development so in general shipping a broken web page is fine - it wont cause too much damage even when it happens, and it can be fixed quickly).

In Safety Critical Software however, I hope tests have been written for every single change, and everything has been checked over and over again. Tests become a lot more valuable and simply having to re write them, may make you think of problems you have introduced in the code.

</comment><comment><USER55> It's a good idea to record invariants about your code and your problem. Tests are one way, and there are some other ways. It's a good idea to have the checking of invariants be automatic somehow.

Any assumptions about the output of your code that you make but don't record in a checkable form, are something that could potentially be silently broken by a change in the code. And then you're wasting your time debugging rather than solving the problem you're working on.

</comment><comment><USER56> Sounds not very sustainable to me. Ruthless and speedy refactoring is only possible with tests. Better onboarding of new team members is only possible with tests. Updating external libraries is only possible with tests. How many hours did I spent in projects w/o tests figuring out what's going on... things that an easy test could have told me in the first place. In a world where cash (=time) is king, I wouldn't mind having those dollars back.

</comment><comment><USER57> Another day, another link-bait, faux controversy post about testing on HN. TLDR: Writing bad tests makes for a bad time. Do we need a whole article to cover that?

As a side note, all this recent hand wringing over testing reminds me so much of the time when the new breed of version control software was coming out, it was the same kind of accusations about things being "overhyped" and "you can just email a tar file!"

</comment><comment><USER58> My approach to tests is that where you control all dependencies, do tests for core functionality and any tricky parts. After all, you can always hot-fix any breakage since everything is under your control. However, where you have external dependencies (eg: an API that third parties use) you should have fairly robust tests to ensure you are not introducing any regressions.

</comment><comment><USER59> Without due scientific process to back up TDD we are left with such arguments having equal validity as TDD. Without a scientific proof of TDD being superior then we are left with mere opinions on both sides.

NAARP! [http://paddy3118.blogspot.co.uk/2013/02/no-attempt-at- rigoro...](http://paddy3118.blogspot.co.uk/2013/02/no-attempt-at-rigorous- proof.html)

</comment><comment><USER60> Like anything in life, you have to make a judgement. There is no silver bullet. Tests are very painful to maintain in all but the most well understood problems. There is a ton of great software we all rely on that doesn't have much testing. Having a ton of people rely and test beta versions of your code is much more valuable then any test suite. Dare to think.

</comment><comment><USER61> If the author stopped at the title, he would be one hundred percent correct.

It's easy to rant about unit tests. Don't fall into that trap. Be aware that it's a hype, and correct for that fact - and once you do, use your best judgement. In the end, it's you, the engineer, who's shipping the product - not the countless ever-arguing denizens of the internet.

</comment><comment><USER62> Man I like this article so much. I worked at a company that aimed at 90% test coverage. Without taking into account how important the piece of code under test was.

I think the 80/20 rule applies here. Only 20% of your code does 80% of the work. Focus on writing tests for those 20% then your time is much better spent.

</comment><comment><USER63> The importance of testing _obviously_ depends on how severe the consequences of shipping broken code is. If not testing means that some broken UI element on some webpage slips by, that's obviously easier to live with than if not testing means you blow up some $150M piece of hardware.

</comment><comment><USER64> It's true that some tests might get redundant when your functionality changes, but you don't know which part you will throw away at the point you're writing it. Better have that safety net for the part that will need to continue to work after you refactor.

</comment><comment><USER65> [X] is overhyped != [X] is useless

</comment><comment><USER66> His beef is more with unit tests than functional tests, and I can't disagree with that. Functional tests code that will directly impact your users while unit tests are merely there to make the developer's life more comfortable.

</comment><comment><USER67> I'll take a crack at my own over-generalization, albeit one I think is more useful.

Adding strict types (Typescript!) to your code base gives you way more maintainability than testing. Do it first, then if you still needs tests, write them.

</comment><comment><USER68> Can we please stop referring to 'testing' as if it's the same thing as TDD?

</comment><comment><USER69> I think finding a critical balance what to test and what to skip is often overlooked.

</comment><comment><USER70> Test early to minimize the cash investment you are worried about in test.

</comment><comment><USER71> I agree and this is not the only thing that is overhyped right now...

<comment><USER72> Also overhyped... trains, The Lumineers, IPAs.

</comment></comment><comment><USER73> tests should be fast and easy to write , that's why any library should be bundled with things that make it easy ( null classes , mocked classes , ect...).</comment>


Remote debugging for Firefox OS - <AUTHOR> http://comoyo.github.com/blog/2013/02/01/weinre-debugging-firefoxos/

<comment><USER2> If there is any such thing as a universal rule for dealing with women, it is this: don't be creepy.

There are only two reasons to name a project something like this. One is to honor somebody from Vienna, but that has a different spelling (even if we discount the "-re" at the end of this project's name). The other reason is creepy. Being sly about it, as the project page does, is even creepier.

Want to know why women tend more strongly to avoid IT? Stuff like this is why. It's not the science: it's the people.

</comment><comment><USER3> [http://codetheory.in/remote-mobile-web-application- debugging...](http://codetheory.in/remote-mobile-web-application-debugging- with-weinre/)

</comment><comment><USER4> a title straight from puberty, and kind of sexist. partly weinre's fault though. they even tell you to interpret weinre as penis right in the first sentence.

very useful article nevertheless.

<comment><USER5> > _they even tell you to interpret weinre as penis right in the first > sentence._

I don't see it:

> As all mobile developers should know Weinre is the best thing to have > happened to mankind since American Idol got cancelled.

<comment><AUTHOR> No, on the Weinre page:

> weinre is WEb INspector REmote. Pronounced like the word "winery". Or maybe > like the word "weiner". Who knows, really.</comment></comment></comment>


Slime Molds Are Earth's Smallest, Oldest Farmers  - <AUTHOR> http://www.wired.com/wiredscience/2011/01/bacteria-farming-amoeba/

<comment><USER2> Same story, different source:

<http://news.ycombinator.com/item?id=2122544></comment>


Google Web Toolkit showcase: TeamPostgreSQL - <AUTHOR> http://www.teampostgresql.com We have finally released TeamPostgreSQL, web-based administration and team platform for PostgreSQL. I ran a small beta here on HN a few weeks ago.
The application uses a sophisticated AJAX web client and as such is a good showcase for what can be done with GWT in that arena. The interface is complex yet dynamic and customizable and service invocations are fast and immediately reflected on the client.
The server is realized by a slightly modified Apache Tomcat, supporting the well-known JEE features with regards to security, deployment, dynamic configuration etc.
If you'd like to check it out, the download is available at: http://www.teampostgresql.com <comment><AUTHOR> We have finally released TeamPostgreSQL, web-based administration and team platform for PostgreSQL. I ran a small beta here on HN a few weeks ago.

The application uses a sophisticated AJAX web client and as such is a good showcase for what can be done with GWT in that arena. The interface is complex yet dynamic and customizable and service invocations are fast and immediately reflected on the client.

The server is realized by a slightly modified Apache Tomcat, supporting the well-known JEE features with regards to security, deployment, dynamic configuration etc.

If you'd like to check it out, the download is available at: <http://www.teampostgresql.com></comment>


Ask HN: Would you pay for a monthly job market infographic? - <AUTHOR> Imagine a monthly infographic with a solid statistical methodology which informs you about hiring volume, rates, desired skills, sectors hiring, etc in your home town (eg NYC).
Aim is to make sure you as an engineer can value yourself relative to the market for your skills and to make sure you can spot developments and shifts before they get on top of you.
Would you pay $10/month for the regular intel? <comment><USER2> No</comment>


What's the best job choice for a non-technical person at a startup? - <AUTHOR>

Just wondering what your opinion of a great and rewarding role is at a startup. My ambition is to launch my own company when the time is right, but in the meantime I would like to continue learning and meeting like-minded people. I believe my strengths are in creative strategy, growth, and doing what it takes to help startups grow. I would like to hear your thoughts, especially if you have gone through the same challenges:) <comment><USER2> There is a multitude of work done in start-ups that requires coding at all. Testing, customer support, book keeping, social media presence, and my personal favorite, cold calling are just a few. Think, Jobs. To be the best, you must be willing to wear a lot of different hats, and take initiative based on the situation. My advice is to get into a company you believe in and be willing to learn. You will naturally find where you bring the most value.

<comment><AUTHOR> Thanks for the feedback! Doing that now, just joined early-stage startup and learning how to build a growth engine... seems like a natural fit for me.

As they say hindsight is 20/20, I just thought it could be interesting to get people's perspective. Thanks for your advice!

</comment></comment><comment><USER3> The way the world is heading, my advice would be: get technical. Develop a working knowledge of how things work e.g. how web app works, how programming languages work, the internet etc. You don't have to go deep but it's very valuable to have that understanding.

As far as job choice goes, it sounds like you're more of a product developer/manager and or marketer. The thing about startups however, is that roles bleed into each other depending on your skill set. There's not much room for a specialised cog that isn't willing to go outside of their comfort zone when necessary.

Push your boundaries and you'll be happy with the result.

<comment><AUTHOR> I feel like my strengths might not be coding in itself, as I am more of a growth / biz dev personality. However, I do love putting ideas into motion and I am learning to launch my own web apps in my spare time (as simple as they may be!)

I feel like this combo is helping me grow as an entrepreneur. Appreciate your feedback :) -- always pushing the boundaries</comment></comment>


Rdio Developer App: Eavesdrop.io - listen in on Rdio friends - <AUTHOR> http://blog.rdio.com/us/2012/11/developer-app-eavesdrop.html

<comment><USER2> WTF? What sort of BS is this? Now I need to spied on as well while I listen to music. F* this s*. Time to cancel my rdio account!

<comment><USER3> This only is connected to your friends. So, if this is a serious post, then just don't connect with friends on Rdio.

</comment></comment><comment><USER4> Hey everyone! Eavesdrop dev here; we built this for NodeKO and decided to keep it going.</comment>


Introducing the Google Chrome OS (2009) - <AUTHOR> http://googleblog.blogspot.de/2009/07/introducing-google-chrome-os.html <comment><USER2> And the reason why people upvote 4 years old Chrome OS announcment is... ?

<comment><AUTHOR> Have you seen the frontpage of Hacker News lately?

Wikipedia article about a well know person in IT, namely Grace Hopper. A very old and known project that wants to rebuilt some old version of Microsoft Windows. Etc.

<comment><USER3> What's your point? Can you explain why you submitted this blog post about Chrome OS?

</comment></comment></comment><comment><USER4> Original discussion (as far as I can tell):

[https://news.ycombinator.com/item?id=693269](https://news.ycombinator.com/item?id=693269)

</comment><comment><USER5> This submission brings the light and the heat. $XNUM years, huh, that really is something.</comment>


Vermont to pay remote workers 10k to move to the state - bra-ket https://www.wcax.com/content/news/Vermont-to-pay-remote-workers-to-move-to-the-state-503716691.html <comment><AUTHOR> "The state will pay those new residents up to $10,000 over a period of two years. The grants will be awarded on a first-come, first-served basis with $500,000 allocated for the program."

That will recruit 50 workers, plus perhaps a wife/husband/kids. Total roughly 100 people will move to Vermont, maybe.

I think what's more important is that Vermont's Department of Whatever, that created this program, has a purpose for existing. And that department certainly costs more than $500,000.

</comment><comment><USER2> Want high tech remote workers? Build or support a state wide fiber network that includes rural areas... I'd love to move to Vermont for a deal like this, but I can't work remotely on a 5mbps connection, and this "zip code" coverage maps from ISPs make buying a house a gamble. For some Comcast, 10k won't get them to run a line 200ft from the road to your house.

<comment><USER3> Burlington telecom was my ISP when I lived in BTV. 500/500 dedicated fiber (not "up to") for something to the degree of $40/m.

<comment><USER2> good to hear! But what about more suburban and rural costumers?

The chief advantage of telework is reducing living expenses. However, it's very difficult to reduce living expenses is you still need to live in cities or suburbs of larger cities to get reliable and good internet which is typically required for such jobs. My friend with 50GB cap satellite internet is certainly not going to work from home in the IT field.</comment></comment></comment>


Ask HN:  Can some code be considered art? - <AUTHOR>

Some code just seems to have an aesthetic appeal on par with physical beauty.  You just stare at it going "Wow, that's amazingly brilliant." <comment><USER2> According to Tolstoy, anything, which transfers emotions of the author could be considered art.

</comment><comment><USER3> I think many of the quines and polygots out there are beautiful. Plus some of the "code golf" examples, as long as they aren't obfuscated, are usually educational.

</comment><comment><USER4> I consider coding to be something in between art and industry. Creativity and production.

</comment><comment><USER5> Could you give an example?

<comment><AUTHOR> Sure. One of my favorites is still the doctest module in Python library. Elegant is how I would describe it.</comment></comment>