the mounted property type of arbitrary join

[cyjake]

What should the typeof post.comments in following query be?

await Post.findAll().join(Comment, 'comments.postId = posts.id')

currently it's Array<Post { id, comments: Comment { id, content } }>, although I thought the joined comments should be Array as well, namely Array<Post { id, comments: Array<Comment { id, content }> }>

a more detailed example:

// current
[{ "id": 1, comments: { "id": 42, "content": "sofa" } }]

// expected
[{ "id": 1, comments: [{ "id": 42, "content": "sofa" }, { "id": 56, "content": "stool" }] }

this change requires major version bump