Add singular form

Signed-off-by: Rudi Grinberg <rudi.grinberg@gmail.com>

src/jbuild.ml

@@ -1360,11 +1360,11 @@ module Tests = struct
     ; deps    : Dep_conf.t list
     }
 
-  let t =
+  let gen_parse names =
     record
-      (Buildable.t >>= fun buildable ->
+      (Buildable.t                                         >>= fun buildable ->
        field_oslu "link_flags"                             >>= fun link_flags ->
-       field "names" (list (located string))               >>= fun names ->
+       names                                               >>= fun names ->
        field "deps" (list Dep_conf.t) ~default:[]          >>= fun deps ->
        field_o "package" Pkg.t                             >>= fun package ->
        field "locks" (list String_with_vars.t) ~default:[] >>= fun locks ->
@@ -1383,6 +1383,10 @@ module Tests = struct
          ; package
          ; deps
          })
+
+  let multi = gen_parse (field "names" (list (located string)))
+
+  let single = gen_parse (field "name" (located string) >>| List.singleton)
 end
 
 module Copy_files = struct
@@ -1519,7 +1523,10 @@ module Stanzas = struct
        Jbuild_version.t >>| fun _ -> [])
     ; "tests",
       (Syntax.since Stanza.syntax (1, 0) >>= fun () ->
-       (Tests.t >>| fun t -> [Tests t]))
+       (Tests.multi >>| fun t -> [Tests t]))
+    ; "test",
+      (Syntax.since Stanza.syntax (1, 0) >>= fun () ->
+       (Tests.single >>| fun t -> [Tests t]))
     ; "env",
       (Syntax.since Stanza.syntax (1, 0) >>= fun () ->
        loc >>= fun loc ->

src/stdune/list.ml

@@ -102,3 +102,5 @@ let rec assoc t x =
   match t with
   | [] -> None
   | (k, v) :: t -> if x = k then Some v else assoc t x
+
+let singleton x = [x]

src/stdune/list.mli

@@ -38,3 +38,5 @@ val stable_sort : 'a t -> compare:('a -> 'a -> Ordering.t) -> 'a t
 val compare : 'a t -> 'a t -> compare:('a -> 'a -> Ordering.t) -> Ordering.t
 
 val assoc : ('a * 'b) t -> 'a -> 'b option
+
+val singleton : 'a -> 'a t

test/blackbox-tests/test-cases/tests-stanza/dune

@@ -1,2 +1,7 @@
 (tests
- (names expect_test regular_test))
+ (names expect_test regular_test)
+ (modules :standard \ singular))
+
+(test
+ (name singular)
+ (modules singular))

test/blackbox-tests/test-cases/tests-stanza/run.t

@@ -1,4 +1,10 @@
   $ dune runtest --display short
+      ocamldep .singular.eobjs/singular.ml.d
+        ocamlc .singular.eobjs/singular.{cmi,cmo,cmt}
+      ocamlopt .singular.eobjs/singular.{cmx,o}
+      ocamlopt singular.exe
+      singular alias runtest
+  singular test
       ocamldep .expect_test.eobjs/expect_test.ml.d
       ocamldep .expect_test.eobjs/regular_test.ml.d
         ocamlc .expect_test.eobjs/regular_test.{cmi,cmo,cmt}

test/blackbox-tests/test-cases/tests-stanza/singular.ml

@@ -0,0 +1 @@
+print_endline "singular test"