This patch replaces the parameters provided to a service through
`params` by the contract object.
That way, it allows better consistency when accessing input params. For
example, if you have a service without a contract, to access a
parameter, you need to use `params[:my_parameter]`. But with a contract,
you do this through `contract.my_parameter`. Now, with this patch,
you’ll be able to access it through `params.my_parameter` or
`params[:my_parameter]`.
Some methods have been added to the contract object to better mimic a
Hash. That way, when accessing/using `params`, you don’t have to think
too much about it:
- `params.my_key` is also accessible through `params[:my_key]`.
- `params.my_key = value` can also be done through `params[:my_key] =
value`.
- `#slice` and `#merge` are available.
- `#to_hash` has been implemented, so the contract object will be
automatically cast as a hash by Ruby depending on the context. For
example, with an AR model, you can do this: `user.update(**params)`.