Restructure files a bit. Make Date handling relatively robust compared to my first pass at it. Make the failure to construct a generic open API node type throw an error rather than silently omit the node.

Sources/JSONAPIOpenAPI/OpenAPI/Date+OpenAPI.swift

@@ -0,0 +1,40 @@
+//
+//  Date+OpenAPI.swift
+//  JSONAPIOpenAPI
+//
+//  Created by Mathew Polzin on 1/24/19.
+//
+
+import Foundation
+
+extension Date: DateOpenAPINodeType {
+	public static func dateOpenAPINodeGuess(using encoder: JSONEncoder) -> JSONNode? {
+
+		switch encoder.dateEncodingStrategy {
+		case .deferredToDate, .custom:
+			// I don't know if we can say anything about this case without
+			// encoding the Date and looking at it, which is what `primitiveGuess()`
+			// does.
+			return nil
+
+		case .secondsSince1970,
+			 .millisecondsSince1970:
+			return .number(.init(format: .double,
+								 required: true),
+						   .init())
+
+		case .iso8601:
+			return .string(.init(format: .dateTime,
+								 required: true),
+						   .init())
+
+		case .formatted(let formatter):
+			let hasTime = formatter.timeStyle != .none
+			let format: JSONTypeFormat.StringFormat = hasTime ? .dateTime : .date
+
+			return .string(.init(format: format,
+								 required: true),
+						   .init())
+		}
+	}
+}