Merge pull request #21 from abelino/fix/optional-list

An optional list value should return nil if the incoming raw value is nil or not present

Author: amclain

lib/speck.ex

@@ -142,6 +142,14 @@ defmodule Speck do
           end)
 
         case coerced_maplist do
+          {[], []} ->
+            value =
+              if opts[:optional] && is_nil(get_raw_value(value, name)),
+                do: nil,
+                else: []
+
+            {Map.put(fields, name, value), errors}
+
           {value, []} ->
             {Map.put(fields, name, value), errors}
 

protocol/test/optional_map_list.ex

@@ -0,0 +1,10 @@
+struct TestSchema.OptionalMapList
+
+name "optional_map_list"
+
+attribute :status, :atom, values: [:pending, :failed]
+
+attribute [:transactions], optional: true do
+  attribute :id,     :integer
+  attribute :amount, :integer
+end

test/speck_test.exs

@@ -126,6 +126,18 @@ defmodule Speck.Test do
       }}
   end
 
+  test "return nil if optional list is not present" do
+    params = %{
+      "status" => "failed",
+    }
+
+    assert Speck.validate(TestSchema.OptionalMapList, params) ==
+      {:ok, %TestSchema.OptionalMapList{
+        status: :failed,
+        transactions: nil,
+      }}
+  end
+
   test "returns errors if a list can't be coerced" do
     params = %{
       "device_ids" => [-3, 0, 4, 19]