Should attributes with union types should have a type of "attribute-type"?

[pyoor]

The AST generated by parsing an attribute with a union type has a result idlType.type of null. Is there a reason this isn't attribute-type?

Current Results:

{
  "type": "attribute-type",
  "extAttrs": [],
  "generic": "",
  "nullable": false,
  "union": true,
  "idlType": [
    {
      "type": null,
      "extAttrs": [],
      "generic": "",
      "nullable": false,
      "union": false,
      "idlType": "UTF8String"
    },
    {
      "type": null,
      "extAttrs": [],
      "generic": "",
      "nullable": false,
      "union": false,
      "idlType": "CanvasGradient"
    }
  ]
}

Expected results:

{
  "type": "attribute-type",
  "extAttrs": [],
  "generic": "",
  "nullable": false,
  "union": true,
  "idlType": [
    {
      "type": "attribute-type",
      "extAttrs": [],
      "generic": "",
      "nullable": false,
      "union": false,
      "idlType": "UTF8String"
    },
    {
      "type": "attribute-type",
      "extAttrs": [],
      "generic": "",
      "nullable": false,
      "union": false,
      "idlType": "CanvasGradient"
    }
  ]
}

Suggested fix:

diff --git a/lib/productions/type.js b/lib/productions/type.js
index 728fe6f..3e16e29 100644
--- a/lib/productions/type.js
+++ b/lib/productions/type.js
@@ -129,7 +129,7 @@ function union_type(tokeniser, type) {
   ret.type = type || null;
   while (true) {
     const typ =
-      type_with_extended_attributes(tokeniser) ||
+      type_with_extended_attributes(tokeniser, type) ||
       tokeniser.error("No type after open parenthesis or 'or' in union type");
     if (typ.idlType === "any")
       tokeniser.error("Type `any` cannot be included in a union type");

[saschanaz]

This sounds right, except attribute-type itself is kinda redundant now; you can also do type.parent.type === "attribute". Anyway, happy to accept a PR.