Dedup keys when parsing shape maps in ELP

Summary: The Erlang spec allows users to define map types with duplicate keys, wherte the leftmost definition takes precedence. This will be later disallowed in eqWAlizer, but for now, we need to ensure parsing deals with these cases correctly.

Reviewed By: ilya-klyuchnikov, VLanvin

Differential Revision: D59802368

fbshipit-source-id: f551fe2503b1a0e75e998bc732abefb1317bbffa

Author: ruippeixotog

eqwalizer/src/main/scala/com/whatsapp/eqwalizer/ast/ConvertTypes.scala

@@ -128,7 +128,7 @@ class ConvertTypes(module: String) {
           case prop @ OptExtProp(AtomLitExtType(key), _) => (key, prop)
         }
         val isShape = atomKeyedProps.size == props.size
-        if (isShape) ShapeMap(atomKeyedProps.map(toShapeProps(s, _)))
+        if (isShape) ShapeMap(atomKeyedProps.distinctBy(_._1).map(toShapeProps(s, _)))
         else DictMap(c(props.head.key), c(props.head.tp))
       case BuiltinExtType(name) =>
         builtinTypes(name)

eqwalizer/test_projects/check/src/other.erl

@@ -49,3 +49,6 @@ any_as_metadata_neg(M) -> M.
 elab_var_scope(_) ->
     (begin X = 3, X, fun () -> ok end end)(),
     X.
+
+-spec map_with_dup_keys(#{ak => av1, bk => bv1, ak => av2}) -> #{ak => av1, bk => bv1}.
+map_with_dup_keys(M) -> M.

eqwalizer/test_projects/check/src/other.erl.check

@@ -57,3 +57,6 @@ any_as_metadata_neg(M) -> M.               | ERROR   | M.
 elab_var_scope(_) ->                       | OK      |
     (begin X = 3, X, fun () -> ok end end)……         |
     X.                                     |         |
+                                           |         |
+-spec map_with_dup_keys(#{ak => av1, bk =>……         |
+map_with_dup_keys(M) -> M.                 | OK      |