[flow] Suppress errors discovered during non-generic EvalT coming from type sig

Summary:
For non-generic `EvalT`s coming from type sig, we should already have an corresponding error emitted while checking that file, since all non-generic `EvalT` annotations are eagarly evaluated. Therefore, we can just suppress these errors during checking.

Later, when we move more generic EvalTs into the stuck eval system like D84003226, we can remove the non-generic EvalT check. It should be able to completely fix the misplaced error problem for `EvalT`, except for those `EvalT` that has issues exposed only after substitution.

Changelog: [internal]

Reviewed By: panagosg7

Differential Revision: D84390135

fbshipit-source-id: 9037db7a6ee0b89d3cedf43fd2336daee4136c74

Author: SamChou19815

src/typing/flow_js.ml

@@ -6309,21 +6309,47 @@ struct
 
   and mk_type_destructor cx ~trace use_op reason t d id =
     let evaluated = Context.evaluated cx in
-    let result =
-      match Eval.Map.find_opt id evaluated with
-      | Some cached_t -> cached_t
-      | None ->
-        Tvar.mk_no_wrap_where cx reason (fun tvar ->
-            Context.set_evaluated cx (Eval.Map.add id (OpenT tvar) evaluated);
-            evaluate_type_destructor cx ~trace use_op reason t d tvar
-        )
-    in
     if
-      (not (Flow_js_utils.TvarVisitors.has_unresolved_tvars cx t))
-      && not (Flow_js_utils.TvarVisitors.has_unresolved_tvars_in_destructors cx d)
-    then
-      Tvar_resolver.resolve cx result;
-    result
+      Eval.from_type_sig id
+      && Subst_name.Set.is_empty
+           (Type_subst.free_var_finder
+              cx
+              (EvalT { type_ = t; defer_use_t = TypeDestructorT (use_op, reason, d); id })
+           )
+    then (
+      let result =
+        match Eval.Map.find_opt id evaluated with
+        | Some cached_t -> cached_t
+        | None ->
+          let trace = DepthTrace.dummy_trace in
+          Flow_js_utils.map_on_resolved_type cx reason t (fun t ->
+              Tvar_resolver.mk_tvar_and_fully_resolve_no_wrap_where cx reason (fun tvar ->
+                  let errors = Context.errors cx in
+                  let cache_snapshot = Context.take_cache_snapshot cx in
+                  evaluate_type_destructor cx ~trace use_op reason t d tvar;
+                  Context.restore_cache_snapshot cx cache_snapshot;
+                  Context.reset_errors cx errors
+              )
+          )
+      in
+      Context.set_evaluated cx (Eval.Map.add id result evaluated);
+      result
+    ) else
+      let result =
+        match Eval.Map.find_opt id evaluated with
+        | Some cached_t -> cached_t
+        | None ->
+          Tvar.mk_no_wrap_where cx reason (fun tvar ->
+              Context.set_evaluated cx (Eval.Map.add id (OpenT tvar) evaluated);
+              evaluate_type_destructor cx ~trace use_op reason t d tvar
+          )
+      in
+      if
+        (not (Flow_js_utils.TvarVisitors.has_unresolved_tvars cx t))
+        && not (Flow_js_utils.TvarVisitors.has_unresolved_tvars_in_destructors cx d)
+      then
+        Tvar_resolver.resolve cx result;
+      result
 
   and eval_destructor cx ~trace use_op reason t d tout =
     match d with

src/typing/source_or_generated_id.ml

@@ -54,6 +54,10 @@ let generate_id () = Generated (Reason.mk_id ())
 
 let id_of_aloc_id ~type_sig aloc_id = Source { loc = aloc_id; type_sig }
 
+let from_type_sig = function
+  | Source { loc = _; type_sig } -> type_sig
+  | Generated _ -> false
+
 let string_of_id = function
   | Generated id -> string_of_int id
   | Source { type_sig; loc = id } ->

src/typing/source_or_generated_id.mli

@@ -13,6 +13,8 @@ val equal_id : id -> id -> bool
 
 val id_of_aloc_id : type_sig:bool -> ALoc.id -> id
 
+val from_type_sig : id -> bool
+
 val string_of_id : id -> string
 
 val stable_string_of_id : id -> string

src/typing/type.ml

@@ -2266,6 +2266,8 @@ and Eval : sig
 
   val id_of_aloc_id : type_sig:bool -> ALoc.id -> id
 
+  val from_type_sig : id -> bool
+
   val string_of_id : id -> string
 
   val generate_id : unit -> id

tests/incremental_eval_diff/incremental_eval_diff.exp

@@ -13,21 +13,6 @@ References:
                               ^ [1]
 
 
-Error -------------------------------------------------------------------------------------------------------- a.js:8:17
-
-null or undefined [1] is not an object. (FLOW BUG: This is a misplaced error. The original error was raised in file
-`b.js`). [not-an-object]
-
-   a.js:8:17
-   8| export type A = $Values<T>;
-                      ^^^^^^^^^^
-
-References:
-   a.js:8:25
-   8| export type A = $Values<T>;
-                              ^ [1]
-
-
 Error --------------------------------------------------------------------------------------------------------- b.js:6:2
 
 Cannot cast `a` to object type because number [1] is incompatible with object type [2]. [incompatible-type]
@@ -50,4 +35,4 @@ References:
 
 
 
-Found 3 errors
+Found 2 errors

tests/rec/rec.exp

@@ -34,6 +34,18 @@ Invalid trivially recursive definition of `$Values`.  [recursive-definition]
       ^
 
 
+Error ------------------------------------------------------------------------------------- exported_eval_values.js:4:36
+
+Invalid trivially recursive definition of `$Values`. . (FLOW BUG: This is a misplaced error. The original error was
+raised in file `eval_values.js`) [recursive-definition]
+
+                                         v------------------------
+   4| export opaque type Value: number = $Values< // error: cyclic
+   5|   typeof options,
+   6| >;
+      ^
+
+
 Error ------------------------------------------------------------------------------------ exported_eval_values.js:14:22
 
 Invalid trivially recursive definition of `$Values`.  [recursive-definition]
@@ -562,4 +574,4 @@ Invalid trivially recursive definition of `T3`.  [recursive-definition]
 
 
 
-Found 34 errors
+Found 35 errors

tests/speculation_errors/bad_interaction_with_evalt.js

@@ -1,5 +1,5 @@
 import type { Bad, Obj2 } from "./exported_bad_evalt";
 
 declare const bad: Bad;
-bad.get() as Obj2; // error: TODO should not error here, since annotation error should be non-speculative
-bad.get(1) as Obj2; // error: TODO spurious incompatible with empty
+bad.get() as Obj2; // only subtyping error
+bad.get(1) as Obj2; // ok

tests/speculation_errors/speculation_errors.exp

@@ -1,48 +1,18 @@
-Error -------------------------------------------------------------------------------- bad_interaction_with_evalt.js:4:5
+Error -------------------------------------------------------------------------------- bad_interaction_with_evalt.js:4:1
 
-Cannot call `bad.get` because: [incompatible-type]
- - Either cannot access `Obj2` [1] with computed property using string [2].
- - Or function type [3] requires another argument from call of method `get` [4].
+Cannot cast `bad.get()` to `Obj2` because null [1] is incompatible with `Obj2` [2]. [incompatible-type]
 
-   bad_interaction_with_evalt.js:4:5
-   4| bad.get() as Obj2; // error: TODO should not error here, since annotation error should be non-speculative
-          ^^^
-
-References:
-   exported_bad_evalt.js:8:21
-   8| export type Bad = C<Obj2[string]>;
-                          ^^^^ [1]
-   exported_bad_evalt.js:8:26
-   8| export type Bad = C<Obj2[string]>;
-                               ^^^^^^ [2]
-   exported_bad_evalt.js:3:3
-   3|   get(v: T): T;
-        ^^^^^^^^^^^^ [3]
    bad_interaction_with_evalt.js:4:1
-   4| bad.get() as Obj2; // error: TODO should not error here, since annotation error should be non-speculative
-      ^^^^^^^^^ [4]
-
-
-Error -------------------------------------------------------------------------------- bad_interaction_with_evalt.js:5:5
-
-Cannot call `bad.get` because: [incompatible-type]
- - Either number [1] is incompatible with empty [2].
- - Or no arguments are expected by function type [3].
-
-   bad_interaction_with_evalt.js:5:5
-   5| bad.get(1) as Obj2; // error: TODO spurious incompatible with empty
-          ^^^
+   4| bad.get() as Obj2; // only subtyping error
+      ^^^^^^^^^
 
 References:
-   bad_interaction_with_evalt.js:5:9
-   5| bad.get(1) as Obj2; // error: TODO spurious incompatible with empty
-              ^ [1]
-   exported_bad_evalt.js:8:21
-   8| export type Bad = C<Obj2[string]>;
-                          ^^^^^^^^^^^^ [2]
-   exported_bad_evalt.js:2:3
+   exported_bad_evalt.js:2:14
    2|   get(): T | null;
-        ^^^^^^^^^^^^^^^ [3]
+                   ^^^^ [1]
+   bad_interaction_with_evalt.js:4:14
+   4| bad.get() as Obj2; // only subtyping error
+                   ^^^^ [2]
 
 
 Error ------------------------------------------------------------------------------------- errors_intersection.js:13:13
@@ -3942,7 +3912,7 @@ References:
 
 
 
-Found 186 errors
+Found 185 errors
 
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