Attribute's default_value can be modified

[natesalisbury]

It's possible to modify an attribute's default_value and have those modifications carry over to new instances of the model.

Example:

class MyModel
  include Aws::Record

  map_attr :things, default_value: {}
end

> MyModel.new.things[:foo] = :bar
=> :bar
> MyModel.new.things
=> {:foo=>:bar}

[IbottaBaier]

That is because attribute configuration is stored at the class level.

Also, freeze the default value that way this doesn't happen.

[IbottaBaier]

You aren't really using the default value as it is intended (or at least implemented); default value is what to read if the attribute is not present -- you are treating it more like Hash.of_hashes "default value" mechanism (spawning an empty hash when nothing is present).

[natesalisbury]

Can you give me an example of when and how default_value should be used? I've read the description in the code

# @option opts [Object] :default_value Optional attribute used to
#   define a "default value" to be used if the attribute's value on an
#   item is nil or not set at persistence time.

But that still sounds to me like I could use this option to specify that I want an attribute initialized to something.

If you're interested, I've opened a pull request that prevents the default value from getting modified: #70

[IbottaBaier]

The default value is not like MySQL default that adds the value to the record if it is not set -- this is a read-only default value.

class MyRecord
  include Aws::DynamoDB::Record
  integer_attr :id, hash_key: true
  map_attr :the_best, default_value: { cheese: "is great" }
end

record = MyRecord.new(id: 1)
record.the_best #=> { cheese: "is great" }
record.save!
record = MyRecord.find(id: 1)
record.the_best #=> nil

[awood45]

If we have to freeze the value, it's a bug. Reviewing the PR's suitability as a bug fix.

[awood45]

Fixed by #71

[awood45]

Released this update in version 1.1.1