Storing and reading JSON is asymmetrical unless load_raw_value is true

[qwertme]

When not using load_raw_value for a property you still need to serialize the value when setting the property even though you can read it as a Hash.

This is confusing since it is asymmetrical.

When load_raw_value is false I would expect that both reading and writing to the property to behave like accessing a Hash.

[qwertme]

Here is a code example:

For this given class

class Content
  include DataMapper::Resource

  property :id, Serial
  property :hash_tags, String
  property :text, String
  property :template, String
  property :parameters, PgJSON, default: {}

The following behaviour is observed (take a look at command #13 to see the asymmetry)

irb(main):001:0> c = Content.new
=> #<Content @id=nil @hash_tags=nil @text=nil @template=nil @parameters=nil>
irb(main):002:0> c.parameters = {}
=> {}
irb(main):003:0> c.valid?
=> false
irb(main):004:0> c.errors.inspect
=> "#<DataMapper::Validations::ValidationErrors:0x007fd0d0b1faf0 @resource=#<Content @id=nil @hash_tags=nil @text=nil @template=nil @parameters={}>, @errors={:parameters=>[\"Parameters must be of type Object\"]}>"
irb(main):005:0> c.parameters = {}.to_json
=> "{}"
irb(main):006:0> c.valid?
=> true
irb(main):007:0> c.save
=> true
irb(main):008:0> c.reload
=> #<Content @id=1 @hash_tags=<not loaded> @text=<not loaded> @template=<not loaded> @parameters=<not loaded>>
irb(main):009:0> c.parameters
=> {}
irb(main):010:0> c.parameters['a'] = 'A'
=> "A"
irb(main):011:0> c.valid?
=> false
irb(main):012:0> c.errors.inspect
=> "#<DataMapper::Validations::ValidationErrors:0x007fd0d0b1faf0 @resource=#<Content @id=1 @hash_tags=nil @text=nil @template=nil @parameters={\"a\"=>\"A\"}>, @errors={:parameters=>[\"Parameters must be of type Object\"]}>"
irb(main):013:0> c.parameters = c.parameters.to_json
=> "{\"a\":\"A\"}"
irb(main):014:0> c.valid?
=> true