Fix subtyping dict < shape being too lenient

Summary: The root cause of D56416941 is subtyping being too lenient for dynamic dicts to shapes, causing dynamic dicts to be "approximated away" when joining types. This fixes it by considering `#{dynamic() => dynamic()}` to be a subtype of any shape only when the subtyping polarity of the dict is negative. Also change `narrow.adjustMapType` to preserve dynamic maps, to avoid introducing too much noise. Reviewed By: ilya-klyuchnikov Differential Revision: D56416893 fbshipit-source-id: 88e3f68b9e88f6d8b61556a3edbbdad2933a4235
WhatsApp · Apr 22, 2024 · f2556cd · f2556cd
1 parent 1dbdbbd
commit f2556cd
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Showing 5 changed files with 32 additions and 67 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
@@ -475,6 +475,8 @@ class Narrow(pipelineContext: PipelineContext) {
  BoundedDynamicType(adjustMapType(bound, keyT, valT))
  case shapeMap: ShapeMap =>
  adjustShapeMap(shapeMap, keyT, valT)
+ case DictMap(kT, vT) if subtype.isDynamicType(kT) && subtype.isDynamicType(vT) =>
+ DictMap(kT, vT)
  case dictMap: DictMap =>
  adjustDictMap(dictMap, keyT, valT)
  case UnionType(elems) =>

diff --git a/eqwalizer/src/main/scala/com/whatsapp/eqwalizer/tc/Subtype.scala b/eqwalizer/src/main/scala/com/whatsapp/eqwalizer/tc/Subtype.scala
@@ -199,13 +199,12 @@ class Subtype(pipelineContext: PipelineContext) {
  if (!subTypePol(t1, t2, seen)) return false
  }
  true
- case (DictMap(kT, vT), ShapeMap(_)) if isDynamicType(kT) && isDynamicType(vT) =>
- true
  case (DictMap(kT, vT), ShapeMap(props)) =>
  val (reqProps, optProps) = props.partition {
  case ReqProp(_, _) => true
  case OptProp(_, _) => false
  }
+ if (isDynamicType(kT) && isDynamicType(vT) && v1 == -) return true
  if (reqProps.nonEmpty) return false
  val shapeDomain = join(optProps.map(prop => AtomLitType(prop.key)))
  subTypePol(kT, shapeDomain, seen) && props.forall(prop => subTypePol(vT, prop.tp, seen))

diff --git a/eqwalizer/test_projects/check_gradual/src/gradual_complex_types.erl.check b/eqwalizer/test_projects/check_gradual/src/gradual_complex_types.erl.check
@@ -124,7 +124,7 @@ generic(_, _) -> error(stub). | OK |
  (dyn_map(), #{a => atom()}) -> ok. | |
 use_generic_shape(DM, S) -> | ERROR |
  generic(DM, S). | | generic(DM, S).
- | | Expression has type: #S{a => atom()}
+ | | Expression has type: dyn_map() | #S{a => atom()}
  | | Context expected type: 'ok'
  | |
 -spec tuple_mismatch(dyn_map()) -> | |

diff --git a/eqwalizer/test_projects/fault_tolerance/src/fault_tolerance.erl.check b/eqwalizer/test_projects/fault_tolerance/src/fault_tolerance.erl.check
@@ -369,11 +369,11 @@ maps(M) -> | ERROR |
  | | Expression has type: 'b'
  | | Context expected type: number()
  M1 + M2. | | M1.
- | | Expression has type: #D{dynamic() | 'id' => dynamic() | number()}
+ | | Expression has type: #D{dynamic() => dynamic()}
  | | Context expected type: number()
  | | ---
  | | M2.
- | | Expression has type: #D{dynamic() | 'id' => dynamic() | number()}
+ | | Expression has type: #D{dynamic() => dynamic()}
  | | Context expected type: number()
  | | ---
  | | _ + _.

diff --git a/eqwalizer/test_projects/fault_tolerance/src/fault_tolerance.erl.json b/eqwalizer/test_projects/fault_tolerance/src/fault_tolerance.erl.json
@@ -3623,7 +3623,7 @@
  "end": 3252
  },
  "lineAndCol": null,
- "message": "Expression has type: #D{dynamic() | 'id' => dynamic() | number()}\nContext expected type: number()",
+ "message": "Expression has type: #D{dynamic() => dynamic()}\nContext expected type: number()",
  "uri": "https://fb.me/eqwalizer_errors#incompatible_types",
  "code": "incompatible_types",
  "expressionOrNull": "M1",
@@ -3652,39 +3652,21 @@
  "got": {
  "DictMap": {
  "k_type": {
- "UnionType": {
- "tys": [
- {
- "RemoteType": {
- "id": {
- "module": "eqwalizer",
- "name": "dynamic",
- "arity": 0
- }
- }
- },
- {
- "AtomLitType": {
- "atom": "id"
- }
- }
- ]
+ "RemoteType": {
+ "id": {
+ "module": "eqwalizer",
+ "name": "dynamic",
+ "arity": 0
+ }
  }
  },
  "v_type": {
- "UnionType": {
- "tys": [
- {
- "RemoteType": {
- "id": {
- "module": "eqwalizer",
- "name": "dynamic",
- "arity": 0
- }
- }
- },
- "NumberType"
- ]
+ "RemoteType": {
+ "id": {
+ "module": "eqwalizer",
+ "name": "dynamic",
+ "arity": 0
+ }
  }
  }
  }
@@ -3778,7 +3760,7 @@
  "end": 3257
  },
  "lineAndCol": null,
- "message": "Expression has type: #D{dynamic() | 'id' => dynamic() | number()}\nContext expected type: number()",
+ "message": "Expression has type: #D{dynamic() => dynamic()}\nContext expected type: number()",
  "uri": "https://fb.me/eqwalizer_errors#incompatible_types",
  "code": "incompatible_types",
  "expressionOrNull": "M2",
@@ -3807,39 +3789,21 @@
  "got": {
  "DictMap": {
  "k_type": {
- "UnionType": {
- "tys": [
- {
- "RemoteType": {
- "id": {
- "module": "eqwalizer",
- "name": "dynamic",
- "arity": 0
- }
- }
- },
- {
- "AtomLitType": {
- "atom": "id"
- }
- }
- ]
+ "RemoteType": {
+ "id": {
+ "module": "eqwalizer",
+ "name": "dynamic",
+ "arity": 0
+ }
  }
  },
  "v_type": {
- "UnionType": {
- "tys": [
- {
- "RemoteType": {
- "id": {
- "module": "eqwalizer",
- "name": "dynamic",
- "arity": 0
- }
- }
- },
- "NumberType"
- ]
+ "RemoteType": {
+ "id": {
+ "module": "eqwalizer",
+ "name": "dynamic",
+ "arity": 0
+ }
  }
  }
  }