Raise more accurate ATHR::RequestBody deserialization errors (#490)

src/components/framework/spec/controller/value_resolvers/request_body_spec.cr

@@ -53,18 +53,30 @@ struct RequestBodyResolverTest < ASPEC::TestCase
 
   def test_raises_on_invalid_json : Nil
     expect_raises ATH::Exception::BadRequest, "Malformed JSON payload." do
-      @target.resolve new_request(body: "<abc123>"), self.get_config(MockJSONSerializableEntity)
+      @target.resolve new_request(body: %(<blah>)), self.get_config(MockJSONSerializableEntity)
+    end
+  end
+
+  def test_raises_on_invalid_nested_json : Nil
+    expect_raises ATH::Exception::BadRequest, "Malformed JSON payload." do
+      @target.resolve new_request(body: %({"id": "foo"})), self.get_config(MockJSONSerializableEntity)
+    end
+  end
+
+  def test_raises_on_missing_json_data : Nil
+    expect_raises ATH::Exception::UnprocessableEntity, "Missing JSON attribute: name" do
+      @target.resolve new_request(body: %({"id":10})), self.get_config(MockJSONSerializableEntity)
     end
   end
 
   def test_raises_on_missing_www_form_data : Nil
-    expect_raises ATH::Exception::BadRequest, "Malformed www form data payload." do
+    expect_raises ATH::Exception::UnprocessableEntity, "Missing required property: 'name'." do
       @target.resolve new_request(body: "id=10", format: "form"), self.get_config(MockURISerializableEntity)
     end
   end
 
   def test_raises_on_missing_query_string_data : Nil
-    expect_raises ATH::Exception::BadRequest, "Malformed query string." do
+    expect_raises ATH::Exception::UnprocessableEntity, "Missing required property: 'name'." do
       @target.resolve new_request(query: "id=10"), self.get_config(MockURISerializableEntity, ATHA::MapQueryString, ATHA::MapQueryStringConfiguration.new)
     end
   end

src/components/framework/src/controller/value_resolvers/request_body.cr

@@ -192,9 +192,12 @@ struct Athena::Framework::Controller::ValueResolvers::RequestBody
 
     self.deserialize_form query, parameter.type
   rescue ex : URI::SerializableError
-    raise ATH::Exception::BadRequest.new "Malformed query string.", cause: ex
+    raise ATH::Exception::UnprocessableEntity.new ex.message.not_nil!, cause: ex
+  rescue ex : URI::Error
+    raise ATH::Exception::BadRequest.new "Malformed www form data payload.", cause: ex
   end
 
+  # ameba:disable Metrics/CyclomaticComplexity:
   private def map_request_body(request : ATH::Request, parameter : ATH::Controller::ParameterMetadata, configuration : ATHA::MapRequestBodyConfiguration)
     if !(body = request.body) || body.peek.try &.empty?
       raise ATH::Exception::BadRequest.new "Request does not have a body."
@@ -215,9 +218,21 @@ struct Athena::Framework::Controller::ValueResolvers::RequestBody
     else
       raise ATH::Exception::UnsupportedMediaType.new "Unsupported format."
     end
+  rescue ex : JSON::SerializableError
+    # JSON::Serializable seems to sometimes re-raise parse exceptions as `JSON::SerializableError`,
+    # so we handle those first based on the cause.
+    case cause = ex.cause
+    when JSON::ParseException
+      raise ATH::Exception::BadRequest.new "Malformed JSON payload.", cause: cause
+    else
+      raise ATH::Exception::UnprocessableEntity.new ex.message.not_nil!
+    end
   rescue ex : JSON::ParseException | ASR::Exception::DeserializationException
+    # Otherwise if it really is a `ParseException` we can be assured it's just malformed
     raise ATH::Exception::BadRequest.new "Malformed JSON payload.", cause: ex
   rescue ex : URI::SerializableError
+    raise ATH::Exception::UnprocessableEntity.new ex.message.not_nil!, cause: ex
+  rescue ex : URI::Error
     raise ATH::Exception::BadRequest.new "Malformed www form data payload.", cause: ex
   end