simplify x##property#= 3 into x#property#= 3

Author: bobzhang

jscomp/frontend/ast_exp_apply.ml

@@ -202,25 +202,32 @@ let app_exp_mapper
         ]}
      *)
      | Some {op = "#="; loc; args = [obj; arg]}  ->
-       begin match view_as_app obj ["##"] with
-         | Some { args = [obj; {
-             pexp_desc = 
-               Pexp_ident {txt = Lident name}
+       let gen_assignment obj name name_loc = 
+         sane_property_name_check name_loc name;
+         Exp.constraint_ ~loc
+           { e with
+             pexp_desc =
+               Ast_uncurry_apply.method_apply loc self obj
+                 (name ^ Literals.setter_suffix) [Nolabel,arg]  }
+           (Ast_literal.type_unit ~loc ()) in 
+       begin match obj.pexp_desc with 
+         | Pexp_send (obj , {txt = name; loc = name_loc}) 
+           -> gen_assignment obj name name_loc
+         | _ ->    
+           match view_as_app obj ["##"] with
+           | Some { args = [obj; {
+               pexp_desc = 
+                 Pexp_ident {txt = Lident name}
                | Pexp_constant (
-              Pconst_string
-                  (name, None)); pexp_loc
-           }
-           ]
-           }
-           -> 
-           sane_property_name_check pexp_loc name;
-           Exp.constraint_ ~loc
-             { e with
-               pexp_desc =
-                 Ast_uncurry_apply.method_apply loc self obj
-                   (name ^ Literals.setter_suffix) [Nolabel,arg]  }
-             (Ast_literal.type_unit ~loc ())
-         | _ -> assert false
+                   Pconst_string
+                     (name, None)); pexp_loc = name_loc
+             }
+             ]
+             }
+             -> 
+             gen_assignment obj name name_loc
+           | _ -> 
+            Location.raise_errorf ~loc "invalid #= assignment"
        end
      | Some { op = "|.";  loc; } ->
        Location.raise_errorf ~loc

jscomp/test/hash_sugar_desugar.js

@@ -19,6 +19,11 @@ function h4(u) {
   return u.hi(1, 2);
 }
 
+function g5(u) {
+  u.hi = 3;
+  
+}
+
 function h5(u) {
   u.hi = 3;
 
@@ -45,6 +50,7 @@ exports.h1 = h1;
 exports.h2 = h2;
 exports.h3 = h3;
 exports.h4 = h4;
+exports.g5 = g5;
 exports.h5 = h5;
 exports.h6 = h6;
 exports.h7 = h7;

jscomp/test/hash_sugar_desugar.ml

@@ -29,6 +29,8 @@ let h3 u =
   u ["hi"] (1, 2) 
 *)
 
+let g5 u = 
+  u#hi #= 3   
 let h5 u =
   u ##hi #= 3   
 (* assignment 

jscomp/test/hash_sugar_desugar.mli

@@ -4,7 +4,7 @@ val h1 : < p : 'a; .. > -> 'a
 val h2 : < m : (int -> int -> 'a [@bs]); .. > -> 'a
 val h3 : < hi : int -> int -> 'a; .. > -> 'a
 val h4 : < hi : (int -> int -> 'a [@bs.meth]); .. > -> 'a
-
+val g5 : < hi : int [@bs.set]; .. > -> unit
 val h5 : < hi : int [@bs.set]; .. > -> unit
 (* The inferred type is 
 val h5 : < hi#= : (int -> unit [@bs.meth]); .. > -> unit