Fix crash when using bitwise not on incompatible type (#7965)

* Fix crash when using bitwise not on incompatible type

* CHANGELOG

* Fix comments

Author: cknitt

CHANGELOG.md

@@ -24,6 +24,7 @@
 
 - Fix: use configured Jsx module for constraining component return type. https://github.com/rescript-lang/rescript/pull/7945
 - Undeprecate `Js_OO` module since it is still used with the `@this` attribute. https://github.com/rescript-lang/rescript/pull/7955
+- Fix crash when using bitwise not on incompatible type. https://github.com/rescript-lang/rescript/pull/7965
 
 #### :memo: Documentation
 

compiler/ml/typecore.ml

@@ -3453,9 +3453,14 @@ and translate_unified_ops (env : Env.t) (funct : Typedtree.expression)
         | Tconstr (path, _, _), {string = Some _}
           when Path.same path Predef.path_string ->
           instance_def Predef.type_string
-        | _ ->
-          unify env lhs_type (instance_def Predef.type_int);
-          instance_def Predef.type_int
+        | _ -> (
+          try
+            unify env lhs_type (instance_def Predef.type_int);
+            instance_def Predef.type_int
+          with Ctype.Unify trace ->
+            raise
+              (Error (lhs.exp_loc, env, Expr_type_clash {trace; context = None}))
+          )
       in
       let targs = [(lhs_label, Some lhs)] in
       Some (targs, result_type)

compiler/syntax/src/res_token.ml

@@ -77,9 +77,9 @@ type t =
   | Of
   | Land
   | Lor
-  | Bnot (* Bitwise and: ~~~ *)
-  | Bor (* Bitwise and: ||| *)
-  | Bxor (* Bitwise and: ^^^ *)
+  | Bnot (* Bitwise not: ~~~ *)
+  | Bor (* Bitwise or: ||| *)
+  | Bxor (* Bitwise xor: ^^^ *)
   | Band (* Bitwise and: &&& *)
   | Caret
   | BangEqual

tests/build_tests/super_errors/expected/bitnot_type_mismatch.res.expected

@@ -0,0 +1,10 @@
+
+  We've found a bug for you!
+  /.../fixtures/bitnot_type_mismatch.res:2:12
+
+  1 │ let x = []
+  2 │ let _ = ~~~x
+  3 │ 
+
+  This has type: array<'a>
+  But it's expected to have type: int

tests/build_tests/super_errors/fixtures/bitnot_type_mismatch.res

@@ -0,0 +1,2 @@
+let x = []
+let _ = ~~~x