From 6a7988988de607cf94c65bc053524d6a6ab9d33d Mon Sep 17 00:00:00 2001
From: Max VelDink <mveldink@justworks.com>
Date: Tue, 5 Mar 2024 13:00:00 -0500
Subject: [PATCH] feat: Do type coercion before validation when deserializing

---
 lib/typed/serializer.rb                       | 20 ++++++++++++++++---
 lib/typed/validations/validation_results.rb   |  8 ++++++--
 test/typed/hash_serializer_test.rb            | 15 ++++++++++++++
 .../validations/validation_results_test.rb    | 11 +++++-----
 4 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/lib/typed/serializer.rb b/lib/typed/serializer.rb
index f4db1c1..9f369cc 100644
--- a/lib/typed/serializer.rb
+++ b/lib/typed/serializer.rb
@@ -33,14 +33,28 @@ def serialize(struct)
     sig { params(creation_params: Params).returns(DeserializeResult) }
     def deserialize_from_creation_params(creation_params)
       results = schema.fields.map do |field|
-        field.validate(creation_params[field.name])
+        value = creation_params[field.name]
+
+        if value.nil?
+          field.validate(value)
+        elsif value.class != field.type
+          coercion_result = Coercion.coerce(field:, value:)
+
+          if coercion_result.success?
+            field.validate(coercion_result.payload)
+          else
+            Failure.new(Validations::ValidationError.new(coercion_result.error.message))
+          end
+        else
+          field.validate(value)
+        end
       end
 
       Validations::ValidationResults
         .new(results:)
         .combine
-        .and_then do
-          Success.new(schema.target.new(**creation_params))
+        .and_then do |validated_params|
+          Success.new(schema.target.new(**validated_params))
         end
     end
   end
diff --git a/lib/typed/validations/validation_results.rb b/lib/typed/validations/validation_results.rb
index ee5bed3..0148406 100644
--- a/lib/typed/validations/validation_results.rb
+++ b/lib/typed/validations/validation_results.rb
@@ -7,13 +7,17 @@ class ValidationResults < T::Struct
 
       const :results, T::Array[ValidationResult]
 
-      sig { returns(ValidationResult) }
+      sig { returns(Result[ValidatedParams, ValidationError]) }
       def combine
         failing_results = results.select(&:failure?)
 
         case failing_results.length
         when 0
-          Success.blank
+          Success.new(
+            results.each_with_object({}) do |result, validated_params|
+              validated_params[result.payload.name] = result.payload.value
+            end
+          )
         when 1
           Failure.new(T.must(failing_results.first).error)
         else
diff --git a/test/typed/hash_serializer_test.rb b/test/typed/hash_serializer_test.rb
index 7c5729e..60e24a1 100644
--- a/test/typed/hash_serializer_test.rb
+++ b/test/typed/hash_serializer_test.rb
@@ -13,6 +13,12 @@ def test_it_can_simple_serialize
     assert_equal({name: "Max", age: 29}, @serializer.serialize(max))
   end
 
+  def test_it_can_serialize_with_nested_struct
+    hank = Person.new(name: "Hank", age: 38, job: Job.new(title: "Software Developer", salary: 90_000_00))
+
+    assert_equal({name: "Hank", age: 38, job: {title: "Software Developer", salary: 90_000_00}}, @serializer.serialize(hank))
+  end
+
   # Deserialize Tests
 
   def test_it_can_simple_deserialize
@@ -33,6 +39,15 @@ def test_it_can_simple_deserialize_from_string_keys
     assert_payload(Person.new(name: "Max", age: 29), result)
   end
 
+  def test_it_can_deserialize_with_nested_object
+    hank_hash = {name: "Hank", age: 38, job: {title: "Software Developer", salary: 90_000_00}}
+
+    result = @serializer.deserialize(hank_hash)
+
+    assert_success(result)
+    assert_payload(Person.new(name: "Hank", age: 38, job: Job.new(title: "Software Developer", salary: 90_000_00)), result)
+  end
+
   def test_it_reports_validation_errors_on_deserialize
     max_hash = {name: "Max"}
 
diff --git a/test/typed/validations/validation_results_test.rb b/test/typed/validations/validation_results_test.rb
index 657b925..284dcb7 100644
--- a/test/typed/validations/validation_results_test.rb
+++ b/test/typed/validations/validation_results_test.rb
@@ -4,27 +4,28 @@
 
 class ValidationResultsTest < Minitest::Test
   def setup
-    @success = Typed::Success.new("Testing")
+    @success1 = Typed::Success.new(Typed::Validations::ValidatedValue.new(name: :test, value: "testing"))
+    @success2 = Typed::Success.new(Typed::Validations::ValidatedValue.new(name: :test_again, value: 1))
     @error = Typed::Validations::RequiredFieldError.new(field_name: :bad)
     @failure = Typed::Failure.new(@error)
   end
 
   def test_when_0_failures_combine_returns_success
-    result = Typed::Validations::ValidationResults.new(results: [@success]).combine
+    result = Typed::Validations::ValidationResults.new(results: [@success1, @success2]).combine
 
     assert_success(result)
-    assert_nil(result.payload)
+    assert_payload({test: "testing", test_again: 1}, result)
   end
 
   def test_when_1_failure_it_returns_failure_and_error
-    result = Typed::Validations::ValidationResults.new(results: [@success, @failure]).combine
+    result = Typed::Validations::ValidationResults.new(results: [@success1, @failure]).combine
 
     assert_failure(result)
     assert_error(@error, result)
   end
 
   def test_when_multiple_failures_it_returns_wrapped_failures
-    result = Typed::Validations::ValidationResults.new(results: [@failure, @success, @failure]).combine
+    result = Typed::Validations::ValidationResults.new(results: [@failure, @success1, @failure]).combine
 
     assert_failure(result)
     assert_error(