This is an issue with Typescript's structural typing, rather than with the interface itself. Since the new schema object isn't hinted to be an array of

CollectionFieldSchema

, the resulting type of update schema isn't sure to be matching that of

CollectionUpdateSchema

. A solution to this would be to just guard the constant with the

CollectionFieldSchema

type, or just guard the update schema object and define any change in there i.e

const update_schema: CollectionUpdateSchema = {
  fields: [
    {
      name: "title",
      type: "string",
      optional: false,
    },
  ],
};