Add new Alcotest.suite function to make writing tests easier

.ocamlformat-ignore

@@ -0,0 +1,2 @@
+examples/floats.ml
+examples/simple.ml

README.md

@@ -42,29 +42,30 @@ module To_test = struct
 end
 
 (* The tests *)
-let test_lowercase () =
-  Alcotest.(check string) "same string" "hello!" (To_test.lowercase "hELLO!")
-
-let test_capitalize () =
-  Alcotest.(check string) "same string" "World." (To_test.capitalize "world.")
-
-let test_str_concat () =
-  Alcotest.(check string) "same string" "foobar" (To_test.str_concat ["foo"; "bar"])
-
-let test_list_concat () =
-  Alcotest.(check (list int)) "same lists" [1; 2; 3] (To_test.list_concat [1] [2; 3])
-
-(* Run it *)
 let () =
-  let open Alcotest in
-  run "Utils" [
-      "string-case", [
-          test_case "Lower case"     `Quick test_lowercase;
-          test_case "Capitalization" `Quick test_capitalize;
-        ];
-      "string-concat", [ test_case "String mashing" `Quick test_str_concat  ];
-      "list-concat",   [ test_case "List mashing"   `Slow  test_list_concat ];
-    ]
+  Alcotest.suite "Utils" begin fun group ->
+    group "string-case" begin fun case ->
+      case "Lower case" begin fun () ->
+        Alcotest.(check string) "same string" "hello!" (To_test.lowercase "hELLO!")
+      end;
+
+      case "Capitalization" begin fun () ->
+        Alcotest.(check string) "same string" "World." (To_test.capitalize "world.")
+      end;
+    end;
+
+    group "string-concat" begin fun case ->
+      case "String mashing" begin fun () ->
+        Alcotest.(check string) "same string" "foobar" (To_test.str_concat ["foo"; "bar"])
+      end;
+    end;
+
+    group "list-concat" begin fun case ->
+      case ~speed:`Slow "List mashing" begin fun () ->
+        Alcotest.(check (list int)) "same lists" [1; 2; 3] (To_test.list_concat [1] [2; 3])
+      end;
+    end;
+  end
 ```
 
 The result is a self-contained binary which displays the test

examples/floats.ml

@@ -27,28 +27,31 @@ For more information, please refer to <http://unlicense.org/>
 
 let e = epsilon_float
 
-let nan () =
-  Alcotest.(check @@ float e) "NaN is NaN" nan nan;
-  Alcotest.(check @@ neg @@ float e) "NaN is not number" nan 7.;
-  Alcotest.(check @@ neg @@ float e) "number is not NaN" 8. nan
-
-let infinity () =
-  Alcotest.(check @@ float e) "+∞ is +∞" infinity infinity;
-  Alcotest.(check @@ float e) "-∞ is -∞" neg_infinity neg_infinity;
-  Alcotest.(check @@ neg @@ float e) "+∞ is not -∞" infinity neg_infinity;
-  Alcotest.(check @@ neg @@ float e) "-∞ is not +∞" neg_infinity infinity;
-  Alcotest.(check @@ neg @@ float e) "+∞ is not 3" infinity 3.
-
-let others () =
-  Alcotest.(check @@ float e) "0 is 0" 0. 0.;
-  Alcotest.(check @@ float e) "0 is epsilon" 0. e;
-  Alcotest.(check @@ neg @@ float e) "0 is not 1" 0. 1.;
-  Alcotest.(check @@ neg @@ float e) "1 is not 0" 1. 0.;
-  Alcotest.(check @@ float e) ".3 is .3" (0.1 +. 0.2) 0.3
-
-let edge_set = [ ("NaN", `Quick, nan); ("∞", `Quick, infinity) ]
-let others_set = [ ("others", `Quick, others) ]
-
 let () =
-  Alcotest.run "Float tests"
-    [ ("Edge cases", edge_set); ("Other floats", others_set) ]
+  Alcotest.suite "Float tests" begin fun group ->
+    group "Edge cases" begin fun case ->
+      case "NaN" begin fun () ->
+        Alcotest.(check @@ float e) "NaN is NaN" nan nan;
+        Alcotest.(check @@ neg @@ float e) "NaN is not number" nan 7.;
+        Alcotest.(check @@ neg @@ float e) "number is not NaN" 8. nan
+      end;
+
+      case "∞" begin fun () ->
+        Alcotest.(check @@ float e) "+∞ is +∞" infinity infinity;
+        Alcotest.(check @@ float e) "-∞ is -∞" neg_infinity neg_infinity;
+        Alcotest.(check @@ neg @@ float e) "+∞ is not -∞" infinity neg_infinity;
+        Alcotest.(check @@ neg @@ float e) "-∞ is not +∞" neg_infinity infinity;
+        Alcotest.(check @@ neg @@ float e) "+∞ is not 3" infinity 3.
+      end;
+    end;
+
+    group "Other floats" begin fun case ->
+      case "others" begin fun () ->
+        Alcotest.(check @@ float e) "0 is 0" 0. 0.;
+        Alcotest.(check @@ float e) "0 is epsilon" 0. e;
+        Alcotest.(check @@ neg @@ float e) "0 is not 1" 0. 1.;
+        Alcotest.(check @@ neg @@ float e) "1 is not 0" 1. 0.;
+        Alcotest.(check @@ float e) ".3 is .3" (0.1 +. 0.2) 0.3
+      end;
+    end;
+  end

examples/simple.ml

@@ -34,33 +34,27 @@ module To_test = struct
 end
 
 (* The tests *)
-let test_lowercase () =
-  Alcotest.(check string) "same string" "hello!" (To_test.lowercase "hELLO!")
-
-let test_capitalize () =
-  Alcotest.(check string) "same string" "World." (To_test.capitalize "world.")
-
-let test_str_concat () =
-  Alcotest.(check string)
-    "same string" "foobar"
-    (To_test.str_concat [ "foo"; "bar" ])
-
-let test_list_concat () =
-  Alcotest.(check (list int))
-    "same lists" [ 1; 2; 3 ]
-    (To_test.list_concat [ 1 ] [ 2; 3 ])
-
-(* Run it *)
 let () =
-  Alcotest.run "Utils"
-    [
-      ( "string-case",
-        [
-          Alcotest.test_case "Lower case" `Quick test_lowercase;
-          Alcotest.test_case "Capitalization" `Quick test_capitalize;
-        ] );
-      ( "string-concat",
-        [ Alcotest.test_case "String mashing" `Quick test_str_concat ] );
-      ( "list-concat",
-        [ Alcotest.test_case "List mashing" `Slow test_list_concat ] );
-    ]
+  Alcotest.suite "Utils" begin fun group ->
+    group "string-case" begin fun case ->
+      case "Lower case" begin fun () ->
+        Alcotest.(check string) "same string" "hello!" (To_test.lowercase "hELLO!")
+      end;
+
+      case "Capitalization" begin fun () ->
+        Alcotest.(check string) "same string" "World." (To_test.capitalize "world.")
+      end;
+    end;
+
+    group "string-concat" begin fun case ->
+      case "String mashing" begin fun () ->
+        Alcotest.(check string) "same string" "foobar" (To_test.str_concat ["foo"; "bar"])
+      end;
+    end;
+
+    group "list-concat" begin fun case ->
+      case ~speed:`Slow "List mashing" begin fun () ->
+        Alcotest.(check (list int)) "same lists" [1; 2; 3] (To_test.list_concat [1] [2; 3])
+      end;
+    end;
+  end

src/alcotest-engine/cli.ml

@@ -167,6 +167,11 @@ module Make (P : Platform.MAKER) (M : Monad.S) :
   let run =
     Config.User.kcreate (fun config ?argv name tl ->
         run_with_args' config ~argv name (Term.const ()) tl)
+
+  let suite =
+    Config.User.kcreate (fun config ?argv name register ->
+        run_with_args' config ~argv name (Term.const ())
+          (suite_testlist register))
 end
 
 module V1 = struct

src/alcotest-engine/cli_intf.ml

@@ -41,6 +41,38 @@ module V1_types = struct
         effect, and [~argv:\[| "ignored"; "--verbose" |\]] will successfully
         pass the verbose option. *)
 
+    val suite :
+      (?argv:string array -> string -> (unit group -> unit) -> return)
+      with_options
+    (** [suite n register] runs the test suite registered by the registration
+        function [register]. [n] is the name of the tested library.
+
+        Other parameters are the same as they are in [run].
+
+        Example usage:
+
+        {[
+        let () =
+          Alcotest.suite "Int" begin fun group ->
+            group "( + )" begin fun case ->
+              case "positive + positive" begin fun () ->
+                Alcotest.(check int) "1 + 1" 2 (1 + 1)
+              end;
+
+              case "positive + negative" begin fun () ->
+                Alcotest.(check int) "1 + -1" 0 (1 + -1)
+              end;
+            end;
+
+            group "( - )" begin fun case ->
+              (* Not actually slow, just for demonstration purposes *)
+              case ~speed:`Slow "positive - positive" begin fun () ->
+                Alcotest.(check int) "1 - 1" 0 (1 - 1)
+              end;
+            end;
+          end
+        ]} *)
+
     val run_with_args :
       (?argv:string array ->
       string ->

src/alcotest-engine/core.ml

@@ -64,6 +64,8 @@ module Make (P : Platform.MAKER) (M : Monad.S) = struct
   let test_case n s f = (n, s, f)
 
   type 'a test = string * 'a test_case list
+  type 'a case = ?speed:speed_level -> string -> 'a run -> unit
+  type 'a group = string -> ('a case -> unit) -> unit
 
   (* global state *)
   type 'a t = {
@@ -417,6 +419,22 @@ module Make (P : Platform.MAKER) (M : Monad.S) = struct
       ?ci
 
   let run = Config.User.kcreate run'
+
+  let suite_testlist register =
+    let groups = ref [] in
+    let each_group name register =
+      let cases = ref [] in
+      let each_case ?(speed = `Quick) name func =
+        cases := test_case name speed func :: !cases
+      in
+      register each_case;
+      groups := (name, List.rev !cases) :: !groups
+    in
+    register each_group;
+    List.rev !groups
+
+  let suite config name register = run' config name (suite_testlist register)
+  let suite = Config.User.kcreate suite
 end
 
 module V1 = struct

src/alcotest-engine/core_intf.ml

@@ -85,8 +85,13 @@ module V1_types = struct
         - [ci] (default auto-detected). Whether to enable specific logging for a
           CI system. *)
 
+    type 'a case = ?speed:speed_level -> string -> ('a -> return) -> unit
+    type 'a group = string -> ('a case -> unit) -> unit
+
     val run : (string -> unit test list -> return) with_options
     val run_with_args : (string -> 'a -> 'a test list -> return) with_options
+    val suite_testlist : (unit group -> unit) -> unit test list
+    val suite : (string -> (unit group -> unit) -> return) with_options
   end
 
   module type MAKER = functor (_ : Platform.MAKER) (M : Monad.S) -> sig