From 812dd64574aea8a088fe515a96f167b370f7b86c Mon Sep 17 00:00:00 2001
From: Panos Vekris <pvekris@meta.com>
Date: Thu, 2 May 2024 11:26:39 -0700
Subject: [PATCH] [flow][as-const] hints propagate through "as const"

Summary: Changelog: [internal]

Reviewed By: SamChou19815

Differential Revision: D56888740

fbshipit-source-id: b6f972716b5bedeaaf337eb03a4c74fa3c7c872f
---
 src/analysis/env_builder/name_def.ml | 6 ++++--
 tests/as_const/.flowconfig           | 1 +
 tests/as_const/hint.js               | 3 +++
 3 files changed, 8 insertions(+), 2 deletions(-)
 create mode 100644 tests/as_const/hint.js

diff --git a/src/analysis/env_builder/name_def.ml b/src/analysis/env_builder/name_def.ml
index 60fd69fdba6..44bc2441e44 100644
--- a/src/analysis/env_builder/name_def.ml
+++ b/src/analysis/env_builder/name_def.ml
@@ -568,6 +568,8 @@ let expression_is_definitely_synthesizable ~autocomplete_hooks =
     | Ast.Expression.TaggedTemplate _ -> false
     | Ast.Expression.Identifier id -> not (identifier_has_autocomplete ~autocomplete_hooks id)
     | Ast.Expression.StringLiteral _ -> not (literal_has_autocomplete ~autocomplete_hooks loc)
+    | Ast.Expression.AsConstExpression { Ast.Expression.AsConstExpression.expression; _ } ->
+      synthesizable expression
     | Ast.Expression.NumberLiteral _
     | Ast.Expression.BooleanLiteral _
     | Ast.Expression.NullLiteral _
@@ -587,7 +589,6 @@ let expression_is_definitely_synthesizable ~autocomplete_hooks =
     | Ast.Expression.TemplateLiteral _
     | Ast.Expression.This _
     | Ast.Expression.TypeCast _
-    | Ast.Expression.AsConstExpression _
     | Ast.Expression.AsExpression _
     | Ast.Expression.TSSatisfies _
     | Ast.Expression.Update _
@@ -2768,6 +2769,8 @@ class def_finder ~autocomplete_hooks env_info toplevel_scope =
       | Ast.Expression.New expr -> this#visit_new_expression ~hints loc expr
       | Ast.Expression.Unary expr -> this#visit_unary_expression ~hints expr
       | Ast.Expression.Conditional expr -> this#visit_conditional ~hints expr
+      | Ast.Expression.AsConstExpression { Ast.Expression.AsConstExpression.expression; _ } ->
+        this#visit_expression ~hints ~cond expression
       | Ast.Expression.Class _
       | Ast.Expression.Identifier _
       | Ast.Expression.Import _
@@ -2788,7 +2791,6 @@ class def_finder ~autocomplete_hooks env_info toplevel_scope =
       | Ast.Expression.This _
       | Ast.Expression.TypeCast _
       | Ast.Expression.AsExpression _
-      | Ast.Expression.AsConstExpression _
       | Ast.Expression.TSSatisfies _
       | Ast.Expression.Update _
       | Ast.Expression.Yield _ ->
diff --git a/tests/as_const/.flowconfig b/tests/as_const/.flowconfig
index e71c822f78e..484cee84fee 100644
--- a/tests/as_const/.flowconfig
+++ b/tests/as_const/.flowconfig
@@ -1,3 +1,4 @@
 [options]
 all=true
 as_const=true
+experimental.ts_syntax=true
diff --git a/tests/as_const/hint.js b/tests/as_const/hint.js
new file mode 100644
index 00000000000..2339ccbeca8
--- /dev/null
+++ b/tests/as_const/hint.js
@@ -0,0 +1,3 @@
+// hints propagate through "as const"
+const arr: readonly [(x: string) => void] = [(x) => {}] as const; // okay
+const obj: {+f: (x: string) => void} = {f: (x) => {}} as const; // okay