fix error message on curried/uncurried signature mismatch (#6414)

* fix error msg on curried/uncurried sig mismatch

* mark function curry kind in value mismatch

* use expand_head to check type of functions

* try passing tests in CI

* Revert "try passing tests in CI"

This reverts commit 1f1b4b8.

* shorten test file names

* shorten test file names even more

Author: tsnobip

jscomp/build_tests/super_errors/expected/c_for_u_in_c_mode.res.expected

@@ -0,0 +1,28 @@
+
+  We've found a bug for you!
+  /.../fixtures/c_for_u_in_c_mode.res:3:5-5:1
+
+  1 │ module Foo: {
+  2 │   let add: (. int, int) => int
+  3 │ } = {
+  4 │   let add = (a, b) => a + b
+  5 │ }
+  6 │ 
+
+  Signature mismatch:
+  Modules do not match:
+    {
+  let add: (int, int) => int
+}
+  is not included in
+    {
+  let add: (. int, int) => int
+}
+  Values do not match:
+    let add: (int, int) => int (curried)
+  is not included in
+    let add: (. int, int) => int (uncurried)
+  /.../fixtures/c_for_u_in_c_mode.res:2:3-30:
+    Expected declaration
+  /.../fixtures/c_for_u_in_c_mode.res:4:7-9:
+    Actual declaration

jscomp/build_tests/super_errors/expected/c_for_u_in_u_mode.res.expected

@@ -0,0 +1,29 @@
+
+  We've found a bug for you!
+  /.../fixtures/c_for_u_in_u_mode.res:5:5-8:1
+
+  3 │ module Foo: {
+  4 │   let add: (int, int) => int
+  5 │ } = {
+  6 │   @@uncurried.swap
+  7 │   let add = (. a, b) => a + b
+  8 │ }
+  9 │ 
+
+  Signature mismatch:
+  Modules do not match:
+    {
+  let add: (int, int) => int
+}
+  is not included in
+    {
+  let add: (int, int) => int
+}
+  Values do not match:
+    let add: (int, int) => int (curried)
+  is not included in
+    let add: (int, int) => int (uncurried)
+  /.../fixtures/c_for_u_in_u_mode.res:4:3-28:
+    Expected declaration
+  /.../fixtures/c_for_u_in_u_mode.res:7:7-9:
+    Actual declaration

jscomp/build_tests/super_errors/expected/u_for_c_in_c_mode.res.expected

@@ -0,0 +1,28 @@
+
+  We've found a bug for you!
+  /.../fixtures/u_for_c_in_c_mode.res:3:5-5:1
+
+  1 │ module Foo: {
+  2 │   let add: (int, int) => int
+  3 │ } = {
+  4 │   let add = (. a, b) => a + b
+  5 │ }
+  6 │ 
+
+  Signature mismatch:
+  Modules do not match:
+    {
+  let add: (. int, int) => int
+}
+  is not included in
+    {
+  let add: (int, int) => int
+}
+  Values do not match:
+    let add: (. int, int) => int (uncurried)
+  is not included in
+    let add: (int, int) => int (curried)
+  /.../fixtures/u_for_c_in_c_mode.res:2:3-28:
+    Expected declaration
+  /.../fixtures/u_for_c_in_c_mode.res:4:7-9:
+    Actual declaration

jscomp/build_tests/super_errors/expected/u_for_c_in_u_mode.res.expected

@@ -0,0 +1,28 @@
+
+  We've found a bug for you!
+  /.../fixtures/u_for_c_in_u_mode.res:6:5-8:1
+
+  4 │   @@uncurried.swap
+  5 │   let add: (. int, int) => int
+  6 │ } = {
+  7 │   let add = (a, b) => a + b
+  8 │ }
+  9 │ 
+
+  Signature mismatch:
+  Modules do not match:
+    {
+  let add: (int, int) => int
+}
+  is not included in
+    {
+  let add: (int, int) => int
+}
+  Values do not match:
+    let add: (int, int) => int (uncurried)
+  is not included in
+    let add: (int, int) => int (curried)
+  /.../fixtures/u_for_c_in_u_mode.res:5:3-30:
+    Expected declaration
+  /.../fixtures/u_for_c_in_u_mode.res:7:7-9:
+    Actual declaration

jscomp/build_tests/super_errors/fixtures/c_for_u_in_c_mode.res

@@ -0,0 +1,5 @@
+module Foo: {
+  let add: (. int, int) => int
+} = {
+  let add = (a, b) => a + b
+}

jscomp/build_tests/super_errors/fixtures/c_for_u_in_u_mode.res

@@ -0,0 +1,8 @@
+@@uncurried
+
+module Foo: {
+  let add: (int, int) => int
+} = {
+  @@uncurried.swap
+  let add = (. a, b) => a + b
+}

jscomp/build_tests/super_errors/fixtures/u_for_c_in_c_mode.res

@@ -0,0 +1,5 @@
+module Foo: {
+  let add: (int, int) => int
+} = {
+  let add = (. a, b) => a + b
+}

jscomp/build_tests/super_errors/fixtures/u_for_c_in_u_mode.res

@@ -0,0 +1,8 @@
+@@uncurried
+
+module Foo: {
+  @@uncurried.swap
+  let add: (. int, int) => int
+} = {
+  let add = (a, b) => a + b
+}

jscomp/ml/includemod.ml

@@ -533,14 +533,22 @@ let show_locs ppf (loc1, loc2) =
   show_loc "Expected declaration" ppf loc2;
   show_loc "Actual declaration" ppf loc1
 
-let include_err ppf = function
+let include_err ~env ppf = function
   | Missing_field (id, loc, kind) ->
       fprintf ppf "The %s `%a' is required but not provided" kind ident id;
       show_loc "Expected declaration" ppf loc
   | Value_descriptions(id, d1, d2) ->
+      let curry_kind_1, curry_kind_2 = 
+        match (Ctype.expand_head env d1.val_type,  Ctype.expand_head env d2.val_type ) with 
+        | { desc = Tarrow _ }, 
+            { desc = Tconstr (Pident {name = "function$"},_,_)} -> (" (curried)", " (uncurried)")
+        | { desc = Tconstr (Pident {name = "function$"},_,_)}, 
+            { desc = Tarrow _ } -> (" (uncurried)", " (curried)")
+        | _ -> ("", "")
+      in
       fprintf ppf
-        "@[<hv 2>Values do not match:@ %a@;<1 -2>is not included in@ %a@]"
-        (value_description id) d1 (value_description id) d2;
+        "@[<hv 2>Values do not match:@ %a%s@;<1 -2>is not included in@ %a%s@]"
+        (value_description id) d1 curry_kind_1 (value_description id) d2 curry_kind_2;
       show_locs ppf (d1.val_loc, d2.val_loc);
   | Type_declarations(id, d1, d2, errs) ->
       fprintf ppf "@[<v>@[<hv>%s:@;<1 2>%a@ %s@;<1 2>%a@]%a%a@]"
@@ -633,7 +641,7 @@ let context ppf cxt =
 
 let include_err ppf (cxt, env, err) =
   Printtyp.wrap_printing_env env (fun () ->
-    fprintf ppf "@[<v>%a%a@]" context (List.rev cxt) include_err err)
+    fprintf ppf "@[<v>%a%a@]" context (List.rev cxt) (include_err ~env) err)
 
 let buffer = ref Bytes.empty
 let is_big obj =