Add support for partitions in dune

dune-project

@@ -1 +1 @@
-(lang dune 1.10)
+(lang dune 3.8)

libname/ppx_inline_test_libname.ml

@@ -2,6 +2,8 @@ open Ppxlib
 
 let libname = ref None
 
+let partition = ref None
+
 let () =
   Driver.add_arg
     "-inline-test-lib"
@@ -20,11 +22,39 @@ let () =
       | Some lib -> libname := Some lib)
 ;;
 
+let () =
+  Driver.add_arg
+    "-partition"
+    (Arg.String (fun s -> partition := Some s))
+    ~doc:
+      " A partition name to be used by ppx_inline_test allowing to split tests into partitions for parallel executions. "
+;;
+
+
+let () =
+  Driver.Cookies.add_simple_handler
+    "inline-test-partition"
+    Ast_pattern.(estring __)
+    ~f:(function
+      | None -> ()
+      | Some p -> partition := Some p)
+;;
+
 let get () =
   match !libname with
   | None -> None
-  | Some lib ->
-    (match String.index lib ':' with
-     | exception Not_found -> Some (lib, "")
-     | i -> Some (String.sub lib 0 i, String.sub lib (i + 1) (String.length lib - i - 1)))
+  | Some lib  ->
+    (match String.index_opt lib ':' with
+     | None -> Some (lib, match !partition with None -> "" | Some p -> p)
+     | Some i ->
+       let libname = String.sub lib 0 i in
+       let partition0 = String.sub lib (i + 1) (String.length lib - i - 1) in
+       match !partition with
+       | None -> Some (libname, partition0)
+       | Some partition1 ->
+         if String.equal partition0 partition1
+         then Some (libname, partition0)
+         else failwith
+             "ppx_inline_test: [library-name] and [inline-test-partition] disagree."
+    )
 ;;

runner/lib/dune

@@ -1,4 +1,7 @@
 (library (name ppx_inline_test_runner_lib)
  (public_name ppx_inline_test.runner.lib)
  (js_of_ocaml (flags --no-sourcemap) (javascript_files runtime.js))
- (c_names am_testing) (libraries base) (preprocess no_preprocessing))
+ (foreign_stubs
+  (language c)
+  (names am_testing))
+ (libraries base) (preprocess no_preprocessing))

src/dune

@@ -5,5 +5,6 @@
  (preprocess (pps ppxlib.metaquot))
  (inline_tests.backend (runner_libraries ppx_inline_test.runner.lib)
   (generate_runner (echo "let () = Ppx_inline_test_lib.Runtime.exit ();;"))
-  (flags "inline-test-runner" %{library-name} -source-tree-root
+  (list_partitions_flags "inline-test-runner" %{library-name} -list-partitions)
+  (flags "inline-test-runner" %{library-name} -partition %{partition} -source-tree-root
    %{workspace_root} -diff-cmd -)))

test/dune

@@ -41,7 +41,7 @@
    \n"))
  (mode fallback))
 
-(alias (name runtest)
+(rule (alias runtest)
  (deps test.expected test.output test-inlining.expected test-inlining.output)
  (action
   (bash