(* TEST
 expect;
*)

module M1 : sig
  type t =
    | Foo of int * int
end = struct
  type t =
    | Foo of float * int
end;;
[%%expect{|
Lines 4-7, characters 6-3:
4 | ......struct
5 |   type t =
6 |     | Foo of float * int
7 | end..
Error: Signature mismatch:
       Modules do not match:
         sig type t = Foo of float * int end
       is not included in
         sig type t = Foo of int * int end
       Type declarations do not match:
         type t = Foo of float * int
       is not included in
         type t = Foo of int * int
       Constructors do not match:
         "Foo of float * int"
       is not the same as:
         "Foo of int * int"
       The type "float" is not equal to the type "int"
|}];;

module M2 : sig
  type t =
    | Foo of int * int
end = struct
  type t =
    | Foo of float
end;;
[%%expect{|
Lines 4-7, characters 6-3:
4 | ......struct
5 |   type t =
6 |     | Foo of float
7 | end..
Error: Signature mismatch:
       Modules do not match:
         sig type t = Foo of float end
       is not included in
         sig type t = Foo of int * int end
       Type declarations do not match:
         type t = Foo of float
       is not included in
         type t = Foo of int * int
       Constructors do not match:
         "Foo of float"
       is not the same as:
         "Foo of int * int"
       They have different arities.
|}];;

module M3 : sig
  type t =
    | Foo of {x : int; y : int}
end = struct
  type t =
    | Foo of {x : float; y : int}
end;;
[%%expect{|
Lines 4-7, characters 6-3:
4 | ......struct
5 |   type t =
6 |     | Foo of {x : float; y : int}
7 | end..
Error: Signature mismatch:
       Modules do not match:
         sig type t = Foo of { x : float; y : int; } end
       is not included in
         sig type t = Foo of { x : int; y : int; } end
       Type declarations do not match:
         type t = Foo of { x : float; y : int; }
       is not included in
         type t = Foo of { x : int; y : int; }
       Constructors do not match:
         "Foo of { x : float; y : int; }"
       is not the same as:
         "Foo of { x : int; y : int; }"
       Fields do not match:
         "x : float;"
       is not the same as:
         "x : int;"
       The type "float" is not equal to the type "int"
|}];;

module M4 : sig
  type t =
    | Foo of {x : int; y : int}
end = struct
  type t =
    | Foo of float
end;;
[%%expect{|
Lines 4-7, characters 6-3:
4 | ......struct
5 |   type t =
6 |     | Foo of float
7 | end..
Error: Signature mismatch:
       Modules do not match:
         sig type t = Foo of float end
       is not included in
         sig type t = Foo of { x : int; y : int; } end
       Type declarations do not match:
         type t = Foo of float
       is not included in
         type t = Foo of { x : int; y : int; }
       Constructors do not match:
         "Foo of float"
       is not the same as:
         "Foo of { x : int; y : int; }"
       The second uses inline records and the first doesn't.
|}];;

module M5 : sig
  type 'a t =
    | Foo : int -> int t
end = struct
  type 'a t =
    | Foo of 'a
end;;
[%%expect{|
Lines 4-7, characters 6-3:
4 | ......struct
5 |   type 'a t =
6 |     | Foo of 'a
7 | end..
Error: Signature mismatch:
       Modules do not match:
         sig type 'a t = Foo of 'a end
       is not included in
         sig type 'a t = Foo : int -> int t end
       Type declarations do not match:
         type 'a t = Foo of 'a
       is not included in
         type 'a t = Foo : int -> int t
       Constructors do not match:
         "Foo of 'a"
       is not the same as:
         "Foo : int -> int t"
       The second has explicit return type and the first doesn't.
|}];;

module M : sig
  type ('a, 'b) t = A of 'a
end = struct
  type ('a, 'b) t = A of 'b
end;;
[%%expect {|
Lines 3-5, characters 6-3:
3 | ......struct
4 |   type ('a, 'b) t = A of 'b
5 | end..
Error: Signature mismatch:
       Modules do not match:
         sig type ('a, 'b) t = A of 'b end
       is not included in
         sig type ('a, 'b) t = A of 'a end
       Type declarations do not match:
         type ('a, 'b) t = A of 'b
       is not included in
         type ('a, 'b) t = A of 'a
       Constructors do not match:
         "A of 'b"
       is not the same as:
         "A of 'a"
       The type "'b" is not equal to the type "'a"
|}];;

module M : sig
  type ('a, 'b) t = A of 'a
end = struct
  type ('b, 'a) t = A of 'a
end;;
[%%expect {|
Lines 3-5, characters 6-3:
3 | ......struct
4 |   type ('b, 'a) t = A of 'a
5 | end..
Error: Signature mismatch:
       Modules do not match:
         sig type ('b, 'a) t = A of 'a end
       is not included in
         sig type ('a, 'b) t = A of 'a end
       Type declarations do not match:
         type ('b, 'a) t = A of 'a
       is not included in
         type ('a, 'b) t = A of 'a
       Constructors do not match:
         "A of 'a"
       is not the same as:
         "A of 'a"
       The type "'a" is not equal to the type "'b"
|}];;



(** Random additions and deletions of constructors *)

module Addition : sig
  type t =
    | A
    | B
    | C
    | D
end = struct
  type t =
    | A
    | B
    | Beta
    | C
    | D
end
[%%expect {|
Lines 9-16, characters 6-3:
 9 | ......struct
10 |   type t =
11 |     | A
12 |     | B
13 |     | Beta
14 |     | C
15 |     | D
16 | end
Error: Signature mismatch:
       Modules do not match:
         sig type t = A | B | Beta | C | D end
       is not included in
         sig type t = A | B | C | D end
       Type declarations do not match:
         type t = A | B | Beta | C | D
       is not included in
         type t = A | B | C | D
       An extra constructor, "Beta", is provided in the first declaration.
|}]


module Addition : sig
  type t =
    | A
    | B
    | C
    | D
end = struct
  type t =
    | A
    | B
    | D
end
[%%expect {|
Lines 7-12, characters 6-3:
 7 | ......struct
 8 |   type t =
 9 |     | A
10 |     | B
11 |     | D
12 | end
Error: Signature mismatch:
       Modules do not match:
         sig type t = A | B | D end
       is not included in
         sig type t = A | B | C | D end
       Type declarations do not match:
         type t = A | B | D
       is not included in
         type t = A | B | C | D
       A constructor, "C", is missing in the first declaration.
|}]


module Multi: sig
  type t =
    | A
    | B
    | C
    | D
    | E
    | F
    | G
end = struct
  type t =
    | A
    | B
    | Beta
    | C
    | D
    | F
    | G
    | Phi
end

[%%expect {|
Lines 10-20, characters 6-3:
10 | ......struct
11 |   type t =
12 |     | A
13 |     | B
14 |     | Beta
...
17 |     | F
18 |     | G
19 |     | Phi
20 | end
Error: Signature mismatch:
       Modules do not match:
         sig type t = A | B | Beta | C | D | F | G | Phi end
       is not included in
         sig type t = A | B | C | D | E | F | G end
       Type declarations do not match:
         type t = A | B | Beta | C | D | F | G | Phi
       is not included in
         type t = A | B | C | D | E | F | G
       3. An extra constructor, "Beta", is provided in the first declaration.
       5. A constructor, "E", is missing in the first declaration.
       8. An extra constructor, "Phi", is provided in the first declaration.
|}]


(** Swaps and moves *)

module Swap : sig
  type t =
    | A
    | E
    | C
    | D
    | B
end = struct
  type t =
    | Alpha
    | B
    | C
    | D
    | E
end
[%%expect {|
Lines 10-17, characters 6-3:
10 | ......struct
11 |   type t =
12 |     | Alpha
13 |     | B
14 |     | C
15 |     | D
16 |     | E
17 | end
Error: Signature mismatch:
       Modules do not match:
         sig type t = Alpha | B | C | D | E end
       is not included in
         sig type t = A | E | C | D | B end
       Type declarations do not match:
         type t = Alpha | B | C | D | E
       is not included in
         type t = A | E | C | D | B
       1. Constructors have different names, "Alpha" and "A".
       2<->5. Constructors "B" and "E" have been swapped.
|}]


module Move: sig
  type t =
    | A of int
    | B
    | C
    | D
    | E
    | F
end = struct
  type t =
    | A of float
    | B
    | D
    | E
    | F
    | C
end
[%%expect {|
Lines 9-17, characters 6-3:
 9 | ......struct
10 |   type t =
11 |     | A of float
12 |     | B
13 |     | D
14 |     | E
15 |     | F
16 |     | C
17 | end
Error: Signature mismatch:
       Modules do not match:
         sig type t = A of float | B | D | E | F | C end
       is not included in
         sig type t = A of int | B | C | D | E | F end
       Type declarations do not match:
         type t = A of float | B | D | E | F | C
       is not included in
         type t = A of int | B | C | D | E | F
       1. Constructors do not match:
         "A of float"
       is not the same as:
         "A of int"
       The type "float" is not equal to the type "int"
       3->6. Constructor "C" has been moved from position 3 to 6.
|}]


module Imperfect_match: sig
  type t = A | B of int
end = struct
 type t = A | R | C of int | S | B of float
end
[%%expect {|
Lines 3-5, characters 6-3:
3 | ......struct
4 |  type t = A | R | C of int | S | B of float
5 | end
Error: Signature mismatch:
       Modules do not match:
         sig type t = A | R | C of int | S | B of float end
       is not included in
         sig type t = A | B of int end
       Type declarations do not match:
         type t = A | R | C of int | S | B of float
       is not included in
         type t = A | B of int
       2. An extra constructor, "R", is provided in the first declaration.
       3. An extra constructor, "C", is provided in the first declaration.
       4. An extra constructor, "S", is provided in the first declaration.
       5. Constructors do not match:
         "B of float"
       is not the same as:
         "B of int"
       The type "float" is not equal to the type "int"
|}]

module Very_imperfect_match: sig
  type t = A | B of int
end = struct
 type t = A | R | C of float | S | D of int
end
[%%expect {|
Lines 3-5, characters 6-3:
3 | ......struct
4 |  type t = A | R | C of float | S | D of int
5 | end
Error: Signature mismatch:
       Modules do not match:
         sig type t = A | R | C of float | S | D of int end
       is not included in
         sig type t = A | B of int end
       Type declarations do not match:
         type t = A | R | C of float | S | D of int
       is not included in
         type t = A | B of int
       2. An extra constructor, "R", is provided in the first declaration.
       3. An extra constructor, "C", is provided in the first declaration.
       4. An extra constructor, "S", is provided in the first declaration.
       5. Constructors have different names, "D" and "B".
|}]