Fixed longstanding bug with with_read_marks_for

[mikeki]

There was a bug explained with the next code snippets:
Suppose:

message1 = Message.create!
user1 = User.create!
user2 = User.create!
message1.mark_as_read! :for => user1

expect behavior:

messages = Message.with_read_marks_for(user1)
# => [ message1 ] with read_mark_id
messages[0].unread?(user1) #check message1, if is unread? by user1
# => false
messages[0].unread?(user2) #check message1, if is unread? by user2
# => true, expect user2 to have unread message1

current behavior:

messages = Message.with_read_marks_for(user1)
# => [ message1 ] with read_mark_id
messages[0].unread?(user1) #check message1, if is unread? by user1
# => false
messages[0].unread?(user2) #check message1, if is unread? by user2
# => false ===>BUG<===

This happens because with_read_marks_for just joins with the read_mark_id, but there is never any indication as to who owns the read_mark_id, so currently we just assume it belongs to all readables

The same bug was implemented in my previous branch for readers(User), but gets fixed here too.

Fix:

I added read_mark_user_id for readables scope and read_mark_readable_type and read_mark_readable_id for reader scopes.

Now inside unread? and have_read?, besides testing if the record respond_to?(:read_mark_id) we also test if the read_mark_id belongs to the user/readable being tested, otherwise it would load the whole set of unread_by(user)/have_not_read(readable) and verify if the object that we are looking for is present.

[coveralls]

Coverage increased (+0.02%) to 99.47% when pulling aebae63 on mikeki:read_marks_scoped_to_owner into 29dc7c2 on ledermann:master.

[ledermann]

Small bug: Must be compared to readable.class.base_class.name. Also, I would prefer to use && over and and || over or.

[ledermann]

Great description and fix! Thanks @mikeki, will merge soon!

[mikeki]

Addressed your comments.

Thank you :)
When do you plan on releasing a new version?

[coveralls]

Coverage increased (+0.54%) to 100.0% when pulling 613fd67 on mikeki:read_marks_scoped_to_owner into 29dc7c2 on ledermann:master.

[ledermann]

Squashed and merged into 11a2547.
I'm planning a new release for tomorrow. Again, thank you very much for contribution!

[mikeki]

Thank you, and don't worry!