feat(oxcaml): parameterised inline_tests

doc/tests.rst

@@ -288,6 +288,21 @@ a ``deps`` field the ``inline_tests`` field. The argument of this
     (inline_tests (deps data.txt))
     (preprocess (pps ppx_expect)))
 
+Specifying Inline Test arguments for Parameterised Libraries
+------------------------------------------------------------
+
+If your library is parameterised (see
+:doc:`/reference/dune/library_parameter`), you must specify which
+implementation of the parameters to use with the ``arguments`` field:
+
+.. code:: ocaml
+
+   (library
+    (name foo)
+    (parameters a_param b_param)
+    (inline_tests
+      (arguments a_impl b_impl)))
+
 
 Passing Special Arguments to the Test Runner
 --------------------------------------------

src/dune_rules/inline_tests.ml

@@ -264,7 +264,18 @@ include Sub_system.Register_end_point (struct
             Resolve.Memo.List.concat_map backends ~f:(fun (backend : Backend.t) ->
               backend.runner_libraries)
           in
-          let* lib = Lib.DB.resolve lib_db (loc, Library.best_name lib) in
+          let* arguments =
+            Resolve.Memo.lift_memo
+            @@ Memo.List.map info.arguments ~f:(fun (loc, dep) ->
+              let open Memo.O in
+              let+ dep = Lib.DB.resolve lib_db (loc, dep) in
+              loc, dep)
+          in
+          let* lib =
+            let open Memo.O in
+            let+ lib = Lib.DB.resolve lib_db (loc, Library.best_name lib) in
+            Lib.Parameterised.instantiate ~loc lib arguments ~parent_parameters:[]
+          in
           let* more_libs =
             Resolve.Memo.List.map info.libraries ~f:(Lib.DB.resolve lib_db)
           in

src/dune_rules/inline_tests_info.ml

@@ -134,6 +134,7 @@ module Tests = struct
     ; executable_link_flags : Ordered_set_lang.Unexpanded.t
     ; backend : (Loc.t * Lib_name.t) option
     ; libraries : (Loc.t * Lib_name.t) list
+    ; arguments : (Loc.t * Lib_name.t) list
     ; enabled_if : Blang.t
     }
 
@@ -165,6 +166,12 @@ module Tests = struct
                    ocaml_flags, link_flags))
        and+ backend = field_o "backend" (located Lib_name.decode)
        and+ libraries = field "libraries" (repeat (located Lib_name.decode)) ~default:[]
+       and+ arguments =
+         field
+           "arguments"
+           (Dune_lang.Syntax.since Dune_lang.Oxcaml.syntax (0, 1)
+            >>> repeat (located Lib_name.decode))
+           ~default:[]
        and+ modes =
          field
            "modes"
@@ -180,6 +187,7 @@ module Tests = struct
        ; executable_link_flags
        ; backend
        ; libraries
+       ; arguments
        ; modes
        ; enabled_if
        })

src/dune_rules/inline_tests_info.mli

@@ -46,6 +46,7 @@ module Tests : sig
     ; executable_link_flags : Ordered_set_lang.Unexpanded.t
     ; backend : (Loc.t * Lib_name.t) option
     ; libraries : (Loc.t * Lib_name.t) list
+    ; arguments : (Loc.t * Lib_name.t) list
     ; enabled_if : Blang.t
     }
 

src/dune_rules/parameterised_rules.ml

@@ -248,12 +248,19 @@ let build_modules ~sctx ~obj_dir ~modules_obj_dir ~dep_graph ~mode ~requires ~li
     Module_name.Map.add_exn acc (Module.name module_) instance)
 ;;
 
-let dep_graph ~obj_dir ~modules impl_only =
+let dep_graph ~ocaml_version ~preprocess ~obj_dir ~modules impl_only =
+  let pp_map =
+    Staged.unstage
+    @@ Pp_spec.pped_modules_map
+         (Dune_lang.Preprocess.Per_module.without_instrumentation preprocess)
+         ocaml_version
+  in
   let per_module =
     List.fold_left impl_only ~init:Module_name.Unique.Map.empty ~f:(fun acc module_ ->
       let module_name_unique = Module.obj_name module_ in
       let deps =
         let open Action_builder.O in
+        let module_ = pp_map module_ in
         let+ deps =
           Dep_rules.read_immediate_deps_of module_ ~modules ~obj_dir ~ml_kind:Impl
         in
@@ -276,10 +283,8 @@ let obj_dir_for_dep_rules dir =
 let instantiate ~sctx lib =
   let ctx = Super_context.context sctx in
   let build_dir = Context.build_dir ctx in
-  let* { Lib_config.ext_lib; _ } =
-    let+ ocaml = ctx |> Context.ocaml in
-    ocaml.lib_config
-  in
+  let* ocaml = Context.ocaml ctx in
+  let ext_lib = ocaml.lib_config.ext_lib in
   let lib_info = Lib.info lib in
   let modules_obj_dir = Lib_info.obj_dir lib_info in
   let* deps_obj_dir, modules =
@@ -295,7 +300,14 @@ let instantiate ~sctx lib =
       modules_obj_dir, Modules.With_vlib.modules modules
   in
   let impl_only = Modules.With_vlib.impl_only modules in
-  let dep_graph = dep_graph ~obj_dir:deps_obj_dir ~modules impl_only in
+  let dep_graph =
+    dep_graph
+      ~ocaml_version:ocaml.version
+      ~preprocess:(Lib_info.preprocess lib_info)
+      ~obj_dir:deps_obj_dir
+      ~modules
+      impl_only
+  in
   let* requires =
     Lib.closure ~linking:true [ lib ]
     |> Resolve.Memo.map

test/blackbox-tests/test-cases/oxcaml/parameterised-inline-test.t

@@ -0,0 +1,153 @@
+Testing the instantiation of parameterised inline tests.
+
+  $ cat >> dune-project <<EOF
+  > (lang dune 3.20)
+  > (using oxcaml 0.1)
+  > EOF
+
+We first define a parameter signature:
+
+  $ mkdir param
+  $ echo 'val param : string' > param/param.mli
+  $ cat > param/dune <<EOF
+  > (library_parameter (name param))
+  > EOF
+
+Then a parameterised library, which uses inline tests:
+
+  $ mkdir lib
+  $ cat > lib/lib.ml <<EOF
+  > let param = Param.param
+  > let%test _ = Param.param = "impl"
+  > EOF
+  $ cat > lib/dune <<EOF
+  > (library
+  >   (name lib)
+  >   (parameters param)
+  >   (inline_tests)
+  >   (preprocess (pps ppx_inline_test)))
+  > EOF
+
+Running the test fails, because we did not specify an implementation for the
+parameter:
+
+  $ dune runtest
+  File "lib/dune", lines 1-5, characters 0-97:
+  1 | (library
+  2 |   (name lib)
+  3 |   (parameters param)
+  4 |   (inline_tests)
+  5 |   (preprocess (pps ppx_inline_test)))
+  Error: Parameter "param" is missing.
+  -> required by
+     _build/default/lib/.lib.inline-tests/.t.eobjs/native/dune__exe__Main.cmx
+  -> required by _build/default/lib/.lib.inline-tests/inline-test-runner.exe
+  -> required by _build/default/lib/.lib.inline-tests/partitions-best
+  -> required by alias lib/runtest-lib in lib/dune:4
+  -> required by alias lib/runtest in lib/dune:1
+  Hint: Pass an argument implementing param to the dependency, or add
+  (parameters param)
+  [1]
+
+We add an implementation:
+
+  $ mkdir impl
+  $ echo 'let param = "impl"' > impl/impl.ml
+  $ cat > impl/dune <<EOF
+  > (library
+  >   (name impl)
+  >   (implements param))
+  > EOF
+
+And specify that `(inline_tests)` should use it with `(arguments impl)`:
+
+  $ cat > lib/dune <<EOF
+  > (library
+  >   (name lib)
+  >   (parameters param)
+  >   (inline_tests (arguments impl))
+  >   (preprocess (pps ppx_inline_test)))
+  > EOF
+
+It should work:
+
+  $ dune runtest
+
+We break the test to confirm that the inline test is running:
+
+  $ cat > lib/lib.ml <<EOF
+  > let param = "lib(" ^ Param.param ^ ")"
+  > let%test _ = Param.param = "not impl"
+  > EOF
+
+  $ dune runtest
+  File "lib/lib.ml", line 2, characters 0-37: <<Param.param = "not impl">> is false.
+
+  FAILED 1 / 1 tests
+  [1]
+
+Using another implementation:
+
+  $ mkdir not_impl
+  $ echo 'let param = "not impl"' > not_impl/not_impl.ml
+  $ cat > not_impl/dune <<EOF
+  > (library
+  >   (name not_impl)
+  >   (implements param))
+  > EOF
+
+  $ cat > lib/dune <<EOF
+  > (library
+  >   (name lib)
+  >   (parameters param)
+  >   (inline_tests (arguments not_impl))
+  >   (preprocess (pps ppx_inline_test)))
+  > EOF
+
+This now works:
+
+  $ dune runtest
+
+Adding another library which has a dependency on the parameterised `lib`:
+
+  $ mkdir lib2
+  $ cat > lib2/lib2_util.ml <<EOF
+  > let lib_param = Lib.param
+  > EOF
+  $ cat > lib2/lib2.ml <<EOF
+  > let%test _ = Lib2_util.lib_param = "lib(impl)"
+  > EOF
+  $ cat > lib2/dune <<EOF
+  > (library
+  >   (name lib2)
+  >   (parameters param)
+  >   (libraries lib)
+  >   (inline_tests (arguments impl))
+  >   (preprocess (pps ppx_inline_test)))
+  > EOF
+
+(Note that the library has two files, which triggers the inline_test
+preprocessor to generate `.pp.ml` files, which influences how the parameterised
+libraries can read the ocamldep outputs since the filenames are not the
+unpreprocessed ones.)
+
+This should also work:
+
+  $ dune runtest
+
+Using the wrong implementation should break the test again:
+
+  $ cat > lib2/dune <<EOF
+  > (library
+  >   (name lib2)
+  >   (parameters param)
+  >   (libraries lib)
+  >   (inline_tests (arguments not_impl))
+  >   (preprocess (pps ppx_inline_test)))
+  > EOF
+
+  $ dune runtest
+  File "lib2/lib2.ml", line 1, characters 0-46: <<Lib2_util.lib_param = "lib(impl)">> is false.
+
+  FAILED 1 / 1 tests
+  [1]