add error for field defaults that are not primitives or empty arrays

babel · Mar 26, 2021 · 0639927 · 0639927
1 parent aa897f8
commit 0639927
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/packages/babel-types/src/definitions/utils.ts b/packages/babel-types/src/definitions/utils.ts
@@ -279,8 +279,16 @@ export default function defineType(
       const keys = Object.getOwnPropertyNames(inherits.fields);
       for (const key of keys) {
         const field = inherits.fields[key];
+        const def = field.default;
+        if (
+          Array.isArray(def) ? def.length > 0 : def && typeof def === "object"
+        ) {
+          throw new Error(
+            "field defaults can only be primitives or empty arrays currently",
+          );
+        }
         fields[key] = {
-          default: Array.isArray(field.default) ? [] : field.default,
+          default: Array.isArray(def) ? [] : def,
           optional: field.optional,
           validate: field.validate,
         };