Fix 'Unbound module type' errors that occurred when trying to async import modules

CHANGELOG.md

@@ -27,6 +27,7 @@
 - Preserve `@as(...)` decorator on record fields when creating interface. https://github.com/rescript-lang/rescript/pull/7779
 - Fix parse error with nested record types and attributes on the field name that has the nested record type. https://github.com/rescript-lang/rescript/pull/7781
 - Fix ppx resolution with package inside monorepo. https://github.com/rescript-lang/rescript/pull/7776
+- Fix 'Unbound module type' errors that occurred when trying to async import modules. https://github.com/rescript-lang/rescript/pull/7783
 
 #### :memo: Documentation
 

compiler/frontend/bs_builtin_ppx.ml

@@ -568,6 +568,14 @@ let rec structure_mapper ~await_context (self : mapper) (stru : Ast_structure.t)
  aux then_expr @ aux else_expr
  | Pexp_construct (_, Some expr) -> aux expr
  | Pexp_fun {rhs = expr} | Pexp_newtype (_, expr) -> aux expr
+ | Pexp_constraint (expr, _) -> aux expr
+ | Pexp_match (expr, cases) ->
+ let case_results =
+ List.fold_left
+ (fun acc (case : Parsetree.case) -> aux case.pc_rhs @ acc)
+ [] cases
+ in
+ aux expr @ case_results
  | _ -> acc
  in
  aux pvb_expr @ spelunk_vbs acc tl

tests/tests/src/Import.mjs

@@ -120,6 +120,19 @@ async function f7() {
  return 1;
 }
 
+async function f8() {
+ await import("rescript/lib/es6/Belt_MutableQueue.js");
+ return 1;
+}
+
+async function f9(value) {
+ if (value !== undefined) {
+ await import("rescript/lib/es6/Belt_HashMapInt.js");
+ return;
+ }
+
+}
+
 let each = M1.forEach;
 
 let M2;
@@ -145,5 +158,7 @@ export {
  f5,
  f6,
  f7,
+ f8,
+ f9,
 }
 /* Not a pure module */

tests/tests/src/Import.res

@@ -90,3 +90,17 @@ let f7 = async () => {
  0
  }
 }
+
+let f8 = async (): int => {
+ module MQ = await Belt.MutableQueue
+ 1
+}
+
+let f9 = async value => {
+ switch value {
+ | Some(_) =>
+ module HashMapInt = await Belt.HashMap.Int
+ ()
+ | None => ()
+ }
+}