> Unformatted Error Output:
  > File "ast-utils/JSParser.re", line 222, characters 17-47:
  > Error: Unbound record field Expression.Object.Property.key

Error: ast-utils/JSParser.re:222 17-47
219 ¦ | Expression.Object.Property((
220 ¦     entry_loc,
221 ¦     {
222 ¦       Expression.Object.Property.key:
223 ¦         Expression.Object.Property.Identifier((_, key)),
224 ¦       Expression.Object.Property.value:
225 ¦         (value_loc, _) as value_node,

Record field Expression; can't be found in any record type.

Record fields must be "in scope". That means you need to `open TheModule` where the record type is defined.
Alternatively, instead of opening a module, you can prefix the record field name like {TheModule.x: 0, y: 100}.