better refinment of maps: implementation

Summary: under the hood, occurrence typing properly refines the map `#{required := _R1}`, however it is also aliased as `Foo` and occurrence typing doesn't handle such aliasing properly (yet). Aliasing is somewhat handled in narrowing. This diff slightly improves narrowing of map types: if a particular required key doesn't exist among *all* keys - then the narrowing would be an empty type `none()`. Reviewed By: VLanvin Differential Revision: D53179541 fbshipit-source-id: 4161da9276a0340cf0908fe2e997bb09aed08491
j-bahr · Jan 29, 2024 · 5da3a99 · 5da3a99
1 parent 761c4ca
commit 5da3a99
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Showing 2 changed files with 3 additions and 18 deletions.
diff --git a/eqwalizer/src/main/scala/com/whatsapp/eqwalizer/tc/Narrow.scala b/eqwalizer/src/main/scala/com/whatsapp/eqwalizer/tc/Narrow.scala
@@ -192,7 +192,7 @@ class Narrow(pipelineContext: PipelineContext) {
         t
       case BoundedDynamicType(bound) =>
         BoundedDynamicType(withRequiredProp(k, bound))
-      case ShapeMap(props) =>
+      case ShapeMap(props) if props.exists(_.key == k) =>
         ShapeMap(props.map {
           case OptProp(`k`, v) =>
             ReqProp(k, v)

diff --git a/eqwalizer/test_projects/eqwater/src/eqwater_maps.erl.check b/eqwalizer/test_projects/eqwater/src/eqwater_maps.erl.check
@@ -72,22 +72,7 @@ map_occ_07_neg(M) -> M.                    |         | M.
 -type foo() :: #{} | #{required := binary(……         |
                                            |         |
 -spec add_optional(foo(), binary()) -> foo……         |
-add_optional(Foo = #{required := _R1}, Opt…… ERROR   |
-  Foo#{optional => Optional};              |         | ..#{..}.
-                                           |         | Expression has type:   #S{optional := binary()} | #S{optional := binary(), required := binary()}
-                                           |         | Context expected type: foo()
-                                           |         | 
-                                           |         |   #S{optional := binary()} | #S{optional := binary(), required := binary()} is not compatible with foo()
-                                           |         |   because
-                                           |         |   #S{optional := binary()} | #S{optional := binary(), required := binary()} is not compatible with #S{} | #S{optional => binary(), required := binary()}
-                                           |         |   because
-                                           |         |   #S{optional := binary()} is not compatible with #S{} | #S{optional => binary(), required := binary()}
-                                           |         |   because
-                                           |         |   #S{optional := binary()} is not compatible with #S{}
-                                           |         |   These associations do not match:
-                                           |         | 
-                                           |         |   #S{
-                                           |         | +    optional := ...
-                                           |         |   }
+add_optional(Foo = #{required := _R1}, Opt…… OK      |
+  Foo#{optional => Optional};              |         |
 add_optional(Z, _) ->                      |         |
   Z.                                       |         |