@hiredman @shayanjm also this great talk on generative testing https://youtu.be/iYu_TrQJ8iU

hi i'm seeing an error i can't make sense of. I get this error even when I revert back to old commits that were definitely working, remove the target directory, remove .m2 directory, and rebuild from scratch. i'm very confused. how could this error happen with code that used to work? any guidance would be greatly appreciated.

java.lang.IllegalArgumentException: No implementation of method: :query* of protocol: #'reflection.util/IDataSource found for class: reflection.component.datomic.DatomicDataSource

Hello! Can anyone tell me how to make an :after pseudo-selector in the Garden

Garden doesn`t compile :after correct. If i wanna a word in a :content option, then Garden insert the word without ''

So an after doesn`t display at all

And another question How can I append native css files to a result compiled garden file?

Are there known problems with sort and vec? It seems to make a difference whether I use (vec (sort ...)) or (into [] (sort ...)) - the second returns the desired result

Is it safe to say that stest/instrument is not really a replacement for mocks via with-redefs ?

Can you give a specific example? Some quick examples work for me:

(def v [5 7 1 3])
(sort v) -> (1 3 5 7)
(vec (sort v)) -> [1 3 5 7]
(into [] (sort [5 7 1 3])) -> [1 3 5 7]

Can you give a specific example? Some quick examples work for me:

(def v [5 7 1 3])
(sort v) -> (1 3 5 7)
(vec (sort v)) -> [1 3 5 7]
(into [] (sort [5 7 1 3])) -> [1 3 5 7]

What's a good way of using try catch within a loop to break program execution on a function that fails within the loop?

(loop (try ... (recur ...) (catch ...))) doesn't seem right

it’s not even valid clojure

you just can’t recur to a loop point outside a try-catch block

So how could I handle this?

The idea is for the program to explode and notify on any failure, but if I don't catch the error in the loop I'll get the exception but not the stoppage

(try (loop ... (recur ...)) (catch ...)

that works

thanks!

Can one use clojure.spec for verifying an input json file yielding meaningful error messages? this is meant for a command-line tool that takes an input json file that is converted to edn

@matan do you mean verifying that the json is well formed and providing meaningful error messages in the case that it is not? the usual case people seem to be worried about is whether well-formed json has a particular structure. you can definitely use it for the latter case

@lee.justin.m thanks. I'm trying to come up with a pattern that will have some elegance.. will see what I come up with

Is it fair to say stest/instrument mocks should really only be used with generative testing and not standard unit tests?

@lee.justin.m as a curiosity, I have found a json schema validation library a more natural solution to the scneario

Those libraries sport error messages that are almost humane, while covering the entire range of errors that your json schema implies. (I have derived for this a schema from a sample valid json of mine, through those online pages that make this derivation).

@matan i don’t think anyone is elated with the current status of error reporting in spec. the expound library is a big help. phrase looks cool too. I’m pretty sure spec is going to be way more expressive than json schema, but that probably means that json schema can produce higher quality diagnostics. i think there are just tradeoffs

Fully agreed about the tradeoff of course.

Thanks for mentioning those spec add-on libraries, I should have a look...

There's some debate on my team/company over a house style practice of including examples in the code with a function's definition. e.g.

(defn x [y z] ... )
#_(x "foo2321312" "bar134324")

(defn ^{:doc "the doc string"
        :usage ["foo11121212" "wee23322"]}
   x [y z] ...) 

Tough thing is drift. In 6 months will those code samples still work?

@dpsutton most likely no, but also no one would expect them to

then i don't see a benefit to them

because you are developing and you see the sort of thing it is, and then you replace it and execute the code

we like to leave them there as a trace or hint

but if the code doesn't work it just tells you the signature

in practice it's more helpful than it is not

go for it then. i've been burnt by comments that lied to me in the past. i'd drop it in a test and assert something so you have to keep it up to date and it won't lie. but if you get benefit from it go for it

my usual workflow is: 1. write fn 2. write commented examples next to it as I iterate to test things 3. finish writing fn 4. put those commented examples in a deftest somewhere

If it's something that people would refer to as documentation, then I put them in a docstring

We're often dealing with state here, so it's typically not something that would go in a deftest in a way that would be easily repeated by the next person, e.g, in a deftest I would mock the stateful aspects, but the usage for an example is to actually involve the mounted state.

That's why say these are meant to be examples, not tests.

then I usually put them in a docstring so that they appear in people's editors without having to go to the definition site

they'll also appear in generated docs if you decided to go that route at some point

my suggested solution above is similar to a docstring but unlike a docstring it's not difficult to eval inline. At least in cider I'm pretty sure eval-last-sexp won't work inside a string

don't believe so. You could put it in a comment form. the insert and eval commands have gotten better. they are comment aware

but also unlike a docstring it won't show up in my UI when I'm inside the form / hovering over it

if it's just an example I'm usually not trying to eval it

Well that depends on how you integrate the use of this metadata into your editor tooling

I’d be afraid that it would litter up the code. If it works for your team then it works, however I wouldn’t deemphasize good docstrings that describe what goes in and what comes out.

Well it's already part of the culture here, I'm just trying to reduce litter

House styles are house styles

for what it is worth, i do this for state manipulation functions that have sort of complicated data types. i totally love it. i put one or two examples in a comment block. it’s just easier for me to read but drift is what i worry about. i would like to have a little concise test instead of a comment.

the reason i do it is because i always end up searching for a use of the function in the code anyway

@danielglauser (I mean the commented out example style, which does lead to litter increasing)

I think the first place I saw this style of including usage examples in the code it was in some of Rich Hickey's code in core or contrib. I thought it was sloppy in that case as well.

you say sloppy i say pragmatic 🙂

I think it definitely has value and it's underrated as a practice, however one of the reasons people don't like it that it is a "broken window" in appearance that leads to further commented-out junk

slopmatic

Broken windows was the first thing that came to mind. 🙂

Sonian alumni

@rplevy I’m sure some of our colleagues would likely disapprove but I favor consistency over “correctness” and tend to go with a house style, then try and convince other folks that there is a better way. Which it sounds like, is exactly what you are doing. 🙂

anyone know of a great article about datomic that provides examples by analogy? eg. “heres a typical many-to-many relationship in SQL, here’s how you might model that idiomatically in datomic”, “here’s a foreign key contstraint in SQL…” etc.

@noisesmith I googled for a library called slopmatic, searched github, before realizing you were coining a portmanteau of sloppy and pragmatic 😂

it totally sounds like a ruby lib

the datomic docs seem okay. But coming in new, it’s tough to draw the line of “this is a constraint it’s safe to implement in client clojure code” vs “this is something that should be enforced at the schema level”

@nick652 you can really only enforce cardinality (one vs many) and datatype in the schema

if you have other transactional logic beyond that, then there’s transaction functions

Is there a way to make a deps.edn alias depend on another alias?

no

that way lies programming. write a program.

Fair enough. 🙂 Does :main-opts do weird spliting on spaces? I can't seem to pass an inline edn to -co in it.

currently broken, sorry. if you have spaces in edn (not in embedded strings), you can use , instead (since it’s also whitespace)

the corfield comma it's called, i believe

Oh, I hadn't thought about that. Technically my edn would work without the space anyways. I just stuck it in a file to keep it pretty. I just wanted to make sure someone was aware. 🙂

yeah https://dev.clojure.org/jira/browse/TDEPS-56

Thanks