dry-types and dry-struct 1.0.0 released

We’re very happy to announce the release of dry-types and dry-struct 1.0.0! dry-types is one of the most important and foundational gem in the dry-rb organization. It powers attributes in dry-struct, handles coercion in dry-schema, and is used extensively in rom-rb‘s relation schemas. With this 1.0.0 release, we hope it will be adopted by more projects. dry-struct was originally extracted from dry-types and it provides the famous attribute API for your PORO objects.

Huge props go to Nikita Shilnikov who has worked so hard to finalize these releases which bring a lot of improvements. Let’s look at some of the highlights.

Configurable types module

Previously you could include all built-in types into your own module via include Dry::Types.module. This was changed to a configurable module builder. Now you can cherry-pick which type namespaced categories you want, which types should be used by default and even rename namespaces. Here are some examples:

# Cherry-pick which categories you want
module Types
  include Dry.Types(:strict, :nominal, :coercible)
end

Types::String
# => #<Dry::Types[Constrained<Nominal<String> rule=[type?(String)]>]>

Types.constants
# => [:Strict, :Nominal, :Coercible]

# Change default category to be `:coercible`
module Types
  include Dry.Types(default: :coercible)
end

Types::String
# => #<Dry::Types[Constructor<Nominal<String> fn=Kernel.String>]>

# Rename default categories
module Types
  include Dry.Types(strict: :Strong, coercible: :Kernel)
end

Types::Kernel::String
=> #<Dry::Types[Constructor<Nominal<String> fn=Kernel.String>]>

Constructors support prepending and appending

Previously it was only possible to append a constructor function. This was too limiting because it wasn’t easy to extend and re-use existing constructors. Now it’s possible to either append or prepend a new constructor:

to_int = Types::Coercible::Integer
inc = to_int.append { |x| x + 2 }
inc.("1") # => "1" -> 1 -> 3

inc = to_int.prepend { |x| x + "2" }
inc.("1") # => "1" -> "12" -> 12

This feature should be very useful in places like rom-rb’s schemas or dry-schema, where you may want to pre-process data and then re-use existing coercion logic.

Shortcut syntax for optional keys in Hash schemas

You can now use key names ending with ? to denote an optional key. Here’s how it looks in practice in a struct definition:

hash_schema = Types::Hash.schema(email: Types::String, name?: Types::String, age?: Types::Integer)

hash_schema[email: 'jane@doe.org']
# => {:email=>"jane@doe.org"}

hash_schema[email: 'jane@doe.org', name: 'Jane', age: 31]
# => {:email=>"jane@doe.org", :name=>"Jane", :age=>31}

Type-safe coercions by default and Lax types

All the built-in coercion types have been changed to raise exceptions on unexpected input. If you want to get back the original input when coercion fails, rather than getting an exception, you can use Lax types, which will rescue known type-related errors:

Types::Params::Float['oops']
# Dry::Types::CoercionError: invalid value for Float(): "oops"

lax_float = Types::Params::Float.lax
lax_float['oops']
=> "oops"

…and more

There are a lot of other features, improvements, optimizations and fixes in this release. Please refer to the CHANGELOGS for a full overview:

Please give it a go and let us know what you think!

We’re also wrapping up dry-validation and dry-schema 1.0.0, stay tuned for more good news :)