Instrument schematized vars

[ikitommi]

Way to turn schematized functions into wrapped ones that do runtime validation for input & outputs. See https://github.com/jeaye/orchestra

[ikitommi]

see #369.

[ianffcs]

Hi, I was wondering with @narocath and @LeaveNhA about on how move forward on implementing this feature, we got into those
questions:

1. Do we need to add the functions to the default-registry? or create a separate registry for functions?
2. Do we need another m/=> like macro for register data-validators? (like m/def)
3. Do we need to make a global atom for the default-registry? (to swap and add the functions-schemas / to swap and add data-validators schemas)
4. Can we use nsed keyowrds for registering function-schemas / data-validator schemas?
5. Do we want a switch to enable a type of instrumentation of malli?

[ikitommi]

Hi, sorry for keeping you waiting. My 2 cents:

1. all function (var) definitions should be in the m/-function-schemas* (e.g. via m/=>) and instrument should use that
2. have wanted to postpone that for malli 1.0.0, or add an optional malli.global ns before that. Not clear yet
3. see 1, function schemas already have a global registry
4. let's start with just instrumenting vars?
5. maybe later, could start with just malli.instrument/instrument!

the api:

• malli.instrument sounds like a good idea - an optional ns
• instrument! and uninstrument! could be the only public api
  • 0-arity => everything
  • 1-arity => options-map, which should later have namespaced options on how to do things: fail on error, just log errors, filter based on schema properties, inputs, outputs or both, error printer, ...
• nothing fancy for error printing needed now, just bare-bones (e.g. miu/-fail)

the bare minimum would be (adopted from https://github.com/setzer22/malli-instrument):

(require '[malli.core :as m])
(require '[malli.instrument :as mi])

(m/=> foo [:=> [:cat int? int?] string?)
(defn foo [x, y] (+ x y))

;; no implementation needed
(m/=> bar [:=> [:cat int? int?] string?)
  
(mi/instrument!)

(foo 1 2) 
;; =throws=> :malli.instrument.invalid-output {:error ["should be a string"], :value 3, :fn user/foo} 

(bar 1 2) 
;; =throws=> :malli.instrument.invalid-output {:error ["should be a string"], :value 3, :fn user/bar} 

what do you think?

[viebel]

Is someone working on this issue?

[ikitommi]

this seemed stalled so started working on this, see #471.

[ikitommi]

#471 merged in master. the new function schema guide found here: https://github.com/metosin/malli/blob/master/docs/function-schemas.md. This will be released after vacations along with many small changes.

Testing, feedback an improvements most welcome.

[viebel]

That's awesome @ikitommi.
Where will you be back from vacations?