FWIW Here's similar go code (converted by a llm).

func TestReplyAlreadyBookmarked(t *testing.T) {
    var reply PostReply
    err := db.Raw(`
        SELECT pr.* FROM post_replies pr 
        WHERE pr.id IN (
            SELECT post_reply_id FROM post_reply_bookmark WHERE user_id = ?
        ) AND pr.deleted = false 
        LIMIT 1
    `, userID).First(&reply).Error
    
    if err == nil {
        err := putReplySave(auth, map[string]interface{}{
            "comment_id": reply.ID,
            "save":       true,
        })
        
        assert.Error(t, err)
        assert.Equal(t, "This comment has already been bookmarked.", err.Error())
    }
}

You can create in-line data structures AND be a properly typed language.