As a first simple step, let us create an exercise which requires no real effort from the student: any valid OCaml code will be a valid answer for this exercise.
Let us focus on test.ml:
open Test_lib
open Report
let () =
set_result @@
ast_sanity_check code_ast @@ fun () ->
[
Message ([ Text "That was easy!" ], Success 1)
]
This code is executed to grade the student answer. It has access to all the toplevel definitions introduced by the student answer.
The interface for the module Test_lib can be found in
test_lib.mli.
The interface for the module Report can be found in
learnocaml_report.mli.
Test_lib.set_result waits for the final report. A value of type
report can be built from the constructors defined in the module
Report. Two functions are applied to get the final report: first,
Test_lib.ast_sanity_check performs some basic verification on the
OCaml source, typically that some forbidden modules are not used ;
second, it calls the function starting from fun () -> ... to
execute the user testing code.
The user testing code is responsible for three tasks: to test the student answer, to assign a grade to this answer, and to generate an informative report.
In that example, we do not test the user code: therefore only the
typechecking and the sanity checks are performed. If these checks
pass, then the report generates the message That was easy! and
give 1 point to the student.
learn-ocaml build; learn-ocaml serve
At this point, you should see the exercise in the instance opened
on http://localhost:8080. Click on grade to get your point!