Merge pull request #19 from ismasan/shorthand_array_attribute

Shorthand array attribute

README.md

@@ -1061,7 +1061,25 @@ Note that this does NOT work with union'd or piped structs.
 attribute :company, Company | Person do
 ```
 
+#### Shorthand array syntax
+
+```ruby
+attribute :things, [] # Same as attribute :things, Types::Array
+attribute :numbers, [Integer] # Same as attribute :numbers, Types::Array[Integer]
+attribute :people, [Person] # same as attribute :people, Types::Array[Person]
+attribute :friends, [Person] do # same as attribute :friends, Types::Array[Person] do...
+  attribute :phone_number, Integer
+end
+```
+
+Note that, if you want to match an attribute value against a literal array, you need to use `#value`
+
+```ruby
+attribute :one_two_three, Types::Array.value[[1, 2, 3]])
+```
+
 #### Optional Attributes
+
 Using `attribute?` allows for optional attributes. If the attribute is not present, these attribute values will be `nil`
 
 ```ruby

lib/plumb/attributes.rb

@@ -205,12 +205,15 @@ def node_name = :data
       # attribute(:name, String)
       # attribute(:friends, Types::Array) { attribute(:name, String) }
       # attribute(:friends, Types::Array) # same as Types::Array[Types::Any]
+      # attribute(:friends, []) # same as Types::Array[Types::Any]
       # attribute(:friends, Types::Array[Person])
+      # attribute(:friends, [Person])
       #
       def attribute(name, type = Types::Any, &block)
         key = Key.wrap(name)
         name = key.to_sym
         type = Composable.wrap(type)
+
         if block_given? # :foo, Array[Data] or :foo, Struct
           type = __plumb_struct_class__ if type == Types::Any
           type = Plumb.decorate(type) do |node|

spec/data_spec.rb

@@ -173,6 +173,32 @@ class DifferentClass
     expect(office.staff.first.errors[:age]).not_to be_empty
   end
 
+  specify 'shorthand typed array syntax' do
+    klass = Class.new(Types::Data) do
+      attribute :typed_array, [Integer]
+      attribute :untyped_array, []
+      attribute :data_array, [] do
+        attribute :name, String
+      end
+    end
+
+    thing = klass.new(typed_array: [1, 2, 3], untyped_array: [1, 'hello'], data_array: [{ name: 'foo' }])
+    expect(thing.typed_array).to eq([1, 2, 3])
+    expect(thing.untyped_array).to eq([1, 'hello'])
+    expect(thing.data_array.map(&:name)).to eq(['foo'])
+    expect(thing.valid?).to be(true)
+    thing = klass.new(typed_array: [1, 2, '3'])
+    expect(thing.valid?).to be(false)
+  end
+
+  specify 'invalid shorthard array with multiple elements' do
+    expect do
+      klass = Class.new(Types::Data) do
+        attribute :typed_array, [Integer, String]
+      end
+    end.to raise_error(ArgumentError)
+  end
+
   specify 'invalid' do
     user = Types::User.new(
       name: 'Jane',