diff --git a/.gitmodules b/.gitmodules
index 9e0292d..a187044 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -2,3 +2,9 @@
 	path = ostap
 	url = https://github.com/PLTools/ostap.git
 	branch = old+dune
+
+[submodule "ppx_blob"]
+	path = ppx_blob
+	url = https://github.com/actionshrimp/ppx_blob.git
+	branch = fix-for-dune-3
+
diff --git a/.ocamlformat-enable b/.ocamlformat-enable
index ebc7cdb..15bb652 100644
--- a/.ocamlformat-enable
+++ b/.ocamlformat-enable
@@ -1 +1,2 @@
 client.ml
+L3/testL3.ml
\ No newline at end of file
diff --git a/L3/L3.ml b/L3/L3.ml
index d433a33..ff0ec1a 100644
--- a/L3/L3.ml
+++ b/L3/L3.ml
@@ -451,19 +451,3 @@ let json_to_bytecode ~fk ~fk2 : Yojson.Safe.t -> SM.t =
   | _ -> fk2 "ожидался список"
   
 *)
-
-  
-let () = 
-  let input = {|
-let fix = { f x -> f ({ eta -> fix(f, eta) },x) } in 
-( let fac = { self n -> if n<=1 then 1 else  n*self(n-1) fi } in
-  write(fix(fac, 4))  
-)
-|} in 
-  match Parser.parse input with 
-  | `Fail msg -> print_endline msg
-  | `Ok ast -> 
-    match Program.eval [3] ast with 
-    | rez -> Format.printf "%a\n%!" (Format.pp_print_list Format.pp_print_int) rez
-    | exception exc -> print_endline (Printexc.to_string exc)
- 
diff --git a/L3/dune b/L3/dune
index 3bcd626..3652aef 100644
--- a/L3/dune
+++ b/L3/dune
@@ -17,3 +17,20 @@
  (preprocess
   (action
    (run %{project_root}/pp5+gt+plugins+ostap+dump.byte %{input-file}))))
+
+(library
+ (name testL3)
+ (modules testL3)
+ (libraries L3)
+ (inline_tests)
+ (flags
+  (:standard -rectypes))
+ (preprocessor_deps
+  (file t01.l3)
+  (file t02.l3)
+  (file t03.l3)
+  (file t04.l3)
+  (file t05.l3)
+  (file t06.l3))
+ (preprocess
+  (pps ppx_expect ppx_blob)))
diff --git a/L3/testL3.ml b/L3/testL3.ml
new file mode 100644
index 0000000..67cc3c4
--- /dev/null
+++ b/L3/testL3.ml
@@ -0,0 +1,50 @@
+open L3
+
+let test input =
+  match Parser.parse input with
+  | `Fail msg -> print_endline msg
+  | `Ok ast -> (
+      match Program.eval [ 3 ] ast with
+      | rez ->
+          Format.printf "%a\n%!" (Format.pp_print_list Format.pp_print_int) rez
+      | exception exc -> print_endline (Printexc.to_string exc))
+
+let%expect_test " " =
+  test
+    {|
+let fix = { f x -> f ({ eta -> fix(f, eta) },x) } in 
+( let fac = { self n -> if n<=1 then 1 else  n*self(n-1) fi } in
+write(fix(fac, 4))  
+)
+|};
+  [%expect "L3.Program.Undefined(\"fix\")"]
+
+let%expect_test " " =
+  test [%blob "t01.l3"];
+  [%expect "
+    1
+    5"]
+
+let%expect_test " " =
+  test [%blob "t02.l3"];
+  [%expect "
+    543210
+    0"]
+
+let%expect_test " " =
+  test [%blob "t03.l3"];
+  [%expect "120"]
+
+let%expect_test " " =
+  test [%blob "t04.l3"];
+  [%expect "120"]
+
+let%expect_test " " =
+  test [%blob "t05.l3"];
+  [%expect "
+    1111
+    12"]
+
+let%expect_test " " =
+  test [%blob "t06.l3"];
+  [%expect "120"]
diff --git a/ppx_blob b/ppx_blob
new file mode 160000
index 0000000..513d847
--- /dev/null
+++ b/ppx_blob
@@ -0,0 +1 @@
+Subproject commit 513d847e589e0638d90b83ac62467f5e65d9245f