Test: Add a regression test for Std.oneof

test/expected/std.ml/std oneof.out

@@ -0,0 +1 @@
+1 1 2 4 5 5 5 6 7 7 8 9 9 10 103 124 124 134 135 135 160 161 161 175 1461 1913 4545 4684 4968 9349

test/std.ml

@@ -15,4 +15,24 @@ let std_int_range_inclusive_bounds () =
   if values = expected then Lwt.return_unit
   else Test.fail "Did not draw all the integers in the interval"
 
-let register () = std_int_range_inclusive_bounds ()
+let std_oneof () =
+  Regression.register ~__FILE__ ~title:"std oneof" ~tags:["std"; "oneof"]
+  @@ fun () ->
+  let values =
+    Seq.ints 0 |> Seq.take 30
+    |> Seq.map (fun i ->
+           let small_gen = Bam.Std.int ~min:0 ~max:10 () in
+           let medium_gen = Bam.Std.int ~min:100 ~max:200 () in
+           let large_gen = Bam.Std.int ~min:1000 ~max:10_000 () in
+           let gen =
+             Bam.Std.oneof [(3, small_gen); (2, medium_gen); (1, large_gen)]
+           in
+           Bam.Gen.run gen (Bam.Gen.Random.make [|i|]) |> Bam.Tree.root )
+    |> List.of_seq |> List.sort compare
+  in
+  let str = values |> List.map string_of_int |> String.concat " " in
+  Regression.capture str ; Lwt.return_unit
+
+let register () =
+  std_int_range_inclusive_bounds () ;
+  std_oneof ()