Add Arbitrary conformance for UnknownJSONAPIError. Fix weird encoding exception that I cannot quite figure out or explain at the moment.

JSONAPI.playground/Pages/OpenAPI Documentation.xcplaygroundpage/Contents.swift

@@ -10,4 +10,14 @@ encoder.outputFormatting = .prettyPrinted
 
 let personSchemaData = try? encoder.encode(Person.openAPINode())
 
+print("Person Schema")
+print("====")
 print(personSchemaData.map { String(data: $0, encoding: .utf8)! } ?? "Schema Construction Failed")
+print("====")
+
+let dogDocumentSchemaData = try? encoder.encode(SingleDogDocument.openAPINodeWithExample())
+
+print("Dog Document Schema")
+print("====")
+print(dogDocumentSchemaData.map { String(data: $0, encoding: .utf8)! } ?? "Schema Construction Failed")
+print("====")

JSONAPI.playground/Pages/Usage.xcplaygroundpage/Contents.swift

@@ -11,8 +11,6 @@ Please enjoy these examples, but allow me the forced casting and the lack of err
 // MARK: - Create a request or response body with one Dog in it
 let dogFromCode = try! Dog(name: "Buddy", owner: nil)
 
-typealias SingleDogDocument = JSONAPI.Document<SingleResourceBody<Dog>, NoMetadata, NoLinks, NoIncludes, NoAPIDescription, UnknownJSONAPIError>
-
 let singleDogDocument = SingleDogDocument(apiDescription: .none, body: .init(entity: dogFromCode), includes: .none, meta: .none, links: .none)
 
 let singleDogData = try! JSONEncoder().encode(singleDogDocument)
@@ -34,8 +32,6 @@ let dogs = try! [Dog(name: "Buddy", owner: personIds[0]), Dog(name: "Joy", owner
 let houses = [House(attributes: .none, relationships: .none, meta: .none, links: .none), House(attributes: .none, relationships: .none, meta: .none, links: .none)]
 let people = try! [Person(id: personIds[0], name: ["Gary", "Doe"], favoriteColor: "Orange-Red", friends: [], dogs: [dogs[0], dogs[1]], home: houses[0]), Person(id: personIds[1], name: ["Elise", "Joy"], favoriteColor: "Red", friends: [], dogs: [dogs[2]], home: houses[1])]
 
-typealias BatchPeopleDocument = JSONAPI.Document<ManyResourceBody<Person>, NoMetadata, NoLinks, Include2<Dog, House>, NoAPIDescription, UnknownJSONAPIError>
-
 let includes = dogs.map { BatchPeopleDocument.Include($0) } + houses.map { BatchPeopleDocument.Include($0) }
 let batchPeopleDocument = BatchPeopleDocument(apiDescription: .none, body: .init(entities: people), includes: .init(values: includes), meta: .none, links: .none)
 let batchPeopleData = try! JSONEncoder().encode(batchPeopleDocument)

JSONAPI.playground/Sources/Entities.swift

@@ -139,4 +139,6 @@ public enum HouseDescription: EntityDescription {
 
 public typealias House = ExampleEntity<HouseDescription>
 
+public typealias SingleDogDocument = JSONAPI.Document<SingleResourceBody<Dog>, NoMetadata, NoLinks, NoIncludes, NoAPIDescription, UnknownJSONAPIError>
 
+public typealias BatchPeopleDocument = JSONAPI.Document<ManyResourceBody<Person>, NoMetadata, NoLinks, Include2<Dog, House>, NoAPIDescription, UnknownJSONAPIError>

JSONAPI.playground/Sources/OpenAPISupport.swift

@@ -2,6 +2,8 @@ import Foundation
 import JSONAPI
 import JSONAPITesting // for the convenience of literal initialization
 import JSONAPIOpenAPI
+import SwiftCheck
+import JSONAPIArbitrary
 
 extension PersonDescription.Attributes: Sampleable {
 	public static var sample: PersonDescription.Attributes {
@@ -14,3 +16,33 @@ extension PersonDescription.Relationships: Sampleable {
 		return .init(friends: ["1", "2"], dogs: ["2"], home: "1")
 	}
 }
+
+extension DogDescription.Attributes: Arbitrary, Sampleable {
+	public static var arbitrary: Gen<DogDescription.Attributes> {
+		return Gen.compose { c in
+			return DogDescription.Attributes(name: c.generate())
+		}
+	}
+
+	public static var sample: DogDescription.Attributes {
+		return DogDescription.Attributes.arbitrary.generate
+	}
+}
+
+extension DogDescription.Relationships: Arbitrary, Sampleable {
+	public static var arbitrary: Gen<DogDescription.Relationships> {
+		return Gen.compose { c in
+			return DogDescription.Relationships(owner: c.generate())
+		}
+	}
+
+	public static var sample: DogDescription.Relationships {
+		return DogDescription.Relationships.arbitrary.generate
+	}
+}
+
+extension Document: Sampleable where PrimaryResourceBody: Arbitrary, IncludeType: Arbitrary, MetaType: Arbitrary, LinksType: Arbitrary, Error: Arbitrary, APIDescription: Arbitrary {
+	public static var sample: Document {
+		return Document.arbitrary.generate
+	}
+}

Sources/JSONAPIArbitrary/Error+Arbitrary.swift

@@ -0,0 +1,15 @@
+//
+//  Error+Arbitrary.swift
+//  JSONAPIArbitrary
+//
+//  Created by Mathew Polzin on 1/21/19.
+//
+
+import SwiftCheck
+import JSONAPI
+
+extension UnknownJSONAPIError: Arbitrary {
+	public static var arbitrary: Gen<UnknownJSONAPIError> {
+		return Gen.pure(.unknownError)
+	}
+}

Sources/JSONAPIOpenAPI/OpenAPITypes.swift

@@ -267,7 +267,11 @@ public enum JSONNode: Equatable {
 		/// into an allowed value.
 		public let allowedValues: [AnyCodable]?
 
-		public let example: AnyCodable?
+		// I wanted example to be AnyCodable, but alas that causes
+		// runtime problems when encoding in a very strange way.
+		// For now, a String (which is OK by the OpenAPI spec) will
+		// have to do.
+		public let example: String?
 
 		public init(format: Format,
 					required: Bool,
@@ -279,6 +283,8 @@ public enum JSONNode: Equatable {
 			self.nullable = nullable
 			self.allowedValues = allowedValues
 			self.example = example
+				.flatMap { try? JSONEncoder().encode($0)}
+				.flatMap { String(data: $0, encoding: .utf8) }
 		}
 
 		/// Return the optional version of this Context

Tests/JSONAPIOpenAPITests/JSONAPIEntityOpenAPITests.swift

@@ -117,11 +117,6 @@ class JSONAPIEntityOpenAPITests: XCTestCase {
 									 nullable: true,
 									 allowedValues: nil),
 							   .init()))
-
-		let encoder = JSONEncoder()
-		encoder.outputFormatting = .prettyPrinted
-		let string = String(data: try! encoder.encode(node), encoding: .utf8)!
-		print(string)
 	}
 
 	func test_RelationshipsEntity() {
@@ -230,6 +225,8 @@ class JSONAPIEntityOpenAPITests: XCTestCase {
 									 nullable: false,
 									 allowedValues: nil),
 							   manyPointerContext))
+
+		let tmpData = try! JSONEncoder().encode(node)
 	}
 
 	func test_AttributesAndRelationshipsEntity() {