4 ms·

Could not disagree more. For reference, my company (https://circleci.com https://circleci.com) probably has one of the largest test suites in Clojure (approx 16

by pbiggar 13y ago

Could not disagree more. For reference, my company (https://circleci.com https://circleci.com) probably has one of the largest test suites in Clojure (approx 16kLOC in the test suite, > 5000 assertions). The value is testing is that it saves time in the long run. If you don't have a decent test suite, then as your product matures, you become unable to do anything because each new feature breaks a dozen old things. Alex is right about the opportunity cost (see my own post "Testing is bullshit": http://blog.circleci.com/testing-is-bullshit/ http://blog.circleci.com/testing-is-bullshit/). But not testing is also an opportunity cost. Basically you can spend T minutes writing tests, or D minutes debugging problems that tests would have found. If you don't test at all, then D will rapidly (within weeks possibly) become so high that you can't get anything done. By contrast, T will rarely go above 50% of time spent on a project (and if it is, you need to rethink how you test, unless you're building rockets or medical equipment).

puredanger 13y ago
What in particular are you disagreeing with? You seem to be implying that I'm saying not to write tests or that testing isn't valuable but that's not what I said. As I said: "I think tests are highly valuable. I don’t know how I could write high quality code without writing tests." Every Clojure dev I've ever worked with wrote tests and relied on them. My point is that there are costs to consider. I observe that the Clojure community is interested in trying a wide variety of testing approaches that may mitigate some costs of testing, perhaps more so than other communities. I have also worked on a system with a large Clojure test suite (at least 30kLOC), primarily example-based. We found that there was substantial cost (even with many custom-built tools) to maintaining those tests. I've had the same experience maintaing large Java test suites. Recently, I've been doing more with generative testing - I think generative and contracts may give you a better return on your effort than example based testing. But that's a hypothesis I look forward to investigating.
siscia 13y ago
What kind of test you run ? Do you test every single pure functions or you test just abstraction layers ? Or what ?

by pbiggar 13y ago

puredanger 13y ago

What in particular are you disagreeing with? You seem to be implying that I'm saying not to write tests or that testing isn't valuable but that's not what I said. As I said: "I think tests are highly valuable. I don’t know how I could write high quality code without writing tests." Every Clojure dev I've ever worked with wrote tests and relied on them. My point is that there are costs to consider. I observe that the Clojure community is interested in trying a wide variety of testing approaches that may mitigate some costs of testing, perhaps more so than other communities. I have also worked on a system with a large Clojure test suite (at least 30kLOC), primarily example-based. We found that there was substantial cost (even with many custom-built tools) to maintaining those tests. I've had the same experience maintaing large Java test suites. Recently, I've been doing more with generative testing - I think generative and contracts may give you a better return on your effort than example based testing. But that's a hypothesis I look forward to investigating.

siscia 13y ago

What kind of test you run ? Do you test every single pure functions or you test just abstraction layers ? Or what ?