Compiler: fix freevar in presence of assignTarget

Author: hhugo

compiler/lib/js_traverse.ml

@@ -239,7 +239,14 @@ class map : mapper =
           match m#statement (Class_declaration (id, f)) with
           | Class_declaration (id, f) -> ExportClass (id, f)
           | _ -> assert false)
-      | ExportNames l -> ExportNames (List.map ~f:(fun (id, s) -> m#ident id, s) l)
+      | ExportNames l ->
+          ExportNames
+            (List.map
+               ~f:(fun (id, s) ->
+                 match m#expression (EVar id) with
+                 | EVar id -> id, s
+                 | _ -> assert false)
+               l)
       | ExportDefaultFun (Some id, decl) -> (
           match m#statement (Function_declaration (id, decl)) with
           | Function_declaration (id, decl) -> ExportDefaultFun (Some id, decl)
@@ -1020,6 +1027,20 @@ class free =
           cbody#record_block Normal;
           m#merge_block_info cbody;
           EClass (ident_o, cl_decl)
+      | EAssignTarget (ArrayTarget l) ->
+          List.iter l ~f:(function
+            | TargetElementHole -> ()
+            | TargetElementId (i, _) -> m#use_var i
+            | TargetElement _ -> ()
+            | TargetElementSpread _ -> ());
+          super#expression x
+      | EAssignTarget (ObjectTarget l) ->
+          List.iter l ~f:(function
+            | TargetPropertyId (Prop_and_ident i, _) -> m#use_var i
+            | TargetProperty _ -> ()
+            | TargetPropertyMethod _ -> ()
+            | TargetPropertySpread _ -> ());
+          super#expression x
       | _ -> super#expression x
 
     method record_block _ = ()

compiler/tests-compiler/minify.ml

@@ -504,12 +504,12 @@ function f () {
 |};
       [%expect
         {|
-      $ cat "test.min.js"
-        1: function
-        2: f(){var
-        3: a=0;let
-        4: b=0;switch(a){case
-        5: 1:let
-        6: b=1;return b;case
-        7: 2:[b]=a}}
-      |}])
+        $ cat "test.min.js"
+          1: function
+          2: f(){var
+          3: a=0;let
+          4: b=0;switch(a){case
+          5: 1:let
+          6: c=1;return c;case
+          7: 2:[b]=a}}
+        |}])