got some attribute cases added and tested. added some descriptions (custom string convertible)

Sources/JSONAPI/Document/Document.swift

@@ -397,10 +397,10 @@ extension Document: Decodable, CodableJSONAPIDocument where PrimaryResourceBody:
         // TODO come back to this and make robust
 
         guard let metaVal = meta else {
-            throw JSONAPIEncodingError.missingOrMalformedMetadata(path: decoder.codingPath)
+            throw JSONAPICodingError.missingOrMalformedMetadata(path: decoder.codingPath)
         }
         guard let linksVal = links else {
-            throw JSONAPIEncodingError.missingOrMalformedLinks(path: decoder.codingPath)
+            throw JSONAPICodingError.missingOrMalformedLinks(path: decoder.codingPath)
         }
 
         body = .data(.init(primary: data, includes: maybeIncludes ?? Includes<Include>.none, meta: metaVal, links: linksVal))

Sources/JSONAPI/Document/Includes.swift

@@ -32,7 +32,7 @@ public struct Includes<I: Include>: Encodable, Equatable {
         var container = encoder.unkeyedContainer()
 
         guard I.self != NoIncludes.self else {
-            throw JSONAPIEncodingError.illegalEncoding("Attempting to encode Include0, which should be represented by the absense of an 'included' entry altogether.", path: encoder.codingPath)
+            throw JSONAPICodingError.illegalEncoding("Attempting to encode Include0, which should be represented by the absense of an 'included' entry altogether.", path: encoder.codingPath)
         }
 
         for value in values {

Sources/JSONAPI/JSONAPICodingError.swift

@@ -1,11 +1,11 @@
 //
-//  EncodingError.swift
+//  JSONAPICodingError.swift
 //  JSONAPI
 //
 //  Created by Mathew Polzin on 12/7/18.
 //
 
-public enum JSONAPIEncodingError: Swift.Error {
+public enum JSONAPICodingError: Swift.Error {
     case typeMismatch(expected: String, found: String, path: [CodingKey])
     case illegalEncoding(String, path: [CodingKey])
     case illegalDecoding(String, path: [CodingKey])

Sources/JSONAPI/Resource/Poly+PrimaryResource.swift

@@ -22,11 +22,11 @@ public typealias CodablePolyWrapped = EncodablePolyWrapped & Decodable
 
 extension Poly0: CodablePrimaryResource {
     public init(from decoder: Decoder) throws {
-        throw JSONAPIEncodingError.illegalDecoding("Attempted to decode Poly0, which should represent a thing that is not expected to be found in a document.", path: decoder.codingPath)
+        throw JSONAPICodingError.illegalDecoding("Attempted to decode Poly0, which should represent a thing that is not expected to be found in a document.", path: decoder.codingPath)
     }
 
     public func encode(to encoder: Encoder) throws {
-        throw JSONAPIEncodingError.illegalEncoding("Attempted to encode Poly0, which should represent a thing that is not expected to be found in a document.", path: encoder.codingPath)
+        throw JSONAPICodingError.illegalEncoding("Attempted to encode Poly0, which should represent a thing that is not expected to be found in a document.", path: encoder.codingPath)
     }
 }
 

Sources/JSONAPI/Resource/Relationship.swift

@@ -189,7 +189,7 @@ extension ToOneRelationship: Codable where Identifiable.Identifier: OptionalId {
         let type = try identifier.decode(String.self, forKey: .entityType)
 
         guard type == Identifiable.jsonType else {
-            throw JSONAPIEncodingError.typeMismatch(expected: Identifiable.jsonType, found: type, path: decoder.codingPath)
+            throw JSONAPICodingError.typeMismatch(expected: Identifiable.jsonType, found: type, path: decoder.codingPath)
         }
 
         id = Identifiable.Identifier(rawValue: try identifier.decode(Identifiable.Identifier.RawType.self, forKey: .id))
@@ -247,7 +247,7 @@ extension ToManyRelationship: Codable {
             let type = try identifier.decode(String.self, forKey: .entityType)
 
             guard type == Relatable.jsonType else {
-                throw JSONAPIEncodingError.typeMismatch(expected: Relatable.jsonType, found: type, path: decoder.codingPath)
+                throw JSONAPICodingError.typeMismatch(expected: Relatable.jsonType, found: type, path: decoder.codingPath)
             }
 
             newIds.append(Relatable.Identifier(rawValue: try identifier.decode(Relatable.Identifier.RawType.self, forKey: .id)))

Sources/JSONAPI/Resource/Resource Object/ResourceObject.swift

@@ -414,21 +414,25 @@ public extension ResourceObject {
         let type = try container.decode(String.self, forKey: .type)
 
         guard ResourceObject.jsonType == type else {
-            throw JSONAPIEncodingError.typeMismatch(expected: Description.jsonType, found: type, path: decoder.codingPath)
+            throw JSONAPICodingError.typeMismatch(expected: Description.jsonType, found: type, path: decoder.codingPath)
         }
 
         let maybeUnidentified = Unidentified() as? EntityRawIdType
         id = try maybeUnidentified.map { ResourceObject.Id(rawValue: $0) } ?? container.decode(ResourceObject.Id.self, forKey: .id)
 
         do {
-            attributes = try (NoAttributes() as? Description.Attributes) ??
-                container.decode(Description.Attributes.self, forKey: .attributes)
+            attributes = try (NoAttributes() as? Description.Attributes)
+                ?? container.decodeIfPresent(Description.Attributes.self, forKey: .attributes)
+                ?? Description.Attributes(from: EmptyObjectDecoder())
         } catch let decodingError as DecodingError {
             throw ResourceObjectDecodingError(decodingError)
                 ?? decodingError
-        } catch let decodingError as JSONAPIEncodingError {
-            throw ResourceObjectDecodingError(decodingError)
-                ?? decodingError
+        } catch _ as EmptyObjectDecodingError {
+            throw ResourceObjectDecodingError(
+                subjectName: ResourceObjectDecodingError.entireObject,
+                cause: .keyNotFound,
+                location: .attributes
+            )
         }
 
         do {
@@ -438,7 +442,7 @@ public extension ResourceObject {
         } catch let decodingError as DecodingError {
             throw ResourceObjectDecodingError(decodingError)
                 ?? decodingError
-        } catch let decodingError as JSONAPIEncodingError {
+        } catch let decodingError as JSONAPICodingError {
             throw ResourceObjectDecodingError(decodingError)
                 ?? decodingError
         } catch _ as EmptyObjectDecodingError {
@@ -469,21 +473,23 @@ public struct ResourceObjectDecodingError: Swift.Error, Equatable {
         case jsonTypeMismatch(expectedType: String, foundType: String)
     }
 
-    public enum Location: Equatable {
+    public enum Location: String, Equatable {
         case attributes
         case relationships
+
+        var singular: String {
+            switch self {
+            case .attributes: return "attribute"
+            case .relationships: return "relationship"
+            }
+        }
     }
 
     init?(_ decodingError: DecodingError) {
         switch decodingError {
         case .typeMismatch(let expectedType, let ctx):
             (location, subjectName) = Self.context(ctx)
-            let typeString: String
-            if let attrType = expectedType as? AbstractAttributeType {
-                typeString = String(describing: attrType.rawValueType)
-            } else {
-                typeString = String(describing: expectedType)
-            }
+            let typeString = String(describing: expectedType)
             cause = .typeMismatch(expectedTypeName: typeString)
         case .valueNotFound(_, let ctx):
             (location, subjectName) = Self.context(ctx)
@@ -497,7 +503,7 @@ public struct ResourceObjectDecodingError: Swift.Error, Equatable {
         }
     }
 
-    init?(_ jsonAPIError: JSONAPIEncodingError) {
+    init?(_ jsonAPIError: JSONAPICodingError) {
         switch jsonAPIError {
         case .typeMismatch(expected: let expected, found: let found, path: let path):
             (location, subjectName) = Self.context(path: path)
@@ -525,3 +531,21 @@ public struct ResourceObjectDecodingError: Swift.Error, Equatable {
         )
     }
 }
+
+extension ResourceObjectDecodingError: CustomStringConvertible {
+    public var description: String {
+        switch cause {
+        case .keyNotFound:
+            if subjectName == ResourceObjectDecodingError.entireObject {
+                return "\(location) object is required and missing."
+            }
+            return "'\(subjectName)' \(location.singular) is required and missing."
+        case .valueNotFound:
+            return "'\(subjectName)' \(location.singular) is not nullable but null."
+        case .typeMismatch(expectedTypeName: let expected):
+            return "'\(subjectName)' \(location.singular) is not a \(expected) as expected."
+        case .jsonTypeMismatch(expectedType: let expected, foundType: let found):
+            return "'\(subjectName)' \(location.singular) is of JSON:API type \"\(found)\" but it was expected to be \"\(expected)\""
+        }
+    }
+}

Tests/JSONAPITests/ResourceObject/ResourceObjectDecodingErrorTests.swift

@@ -23,6 +23,11 @@ final class ResourceObjectDecodingErrorTests: XCTestCase {
                     location: .relationships
                 )
             )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "relationships object is required and missing."
+            )
         }
     }
 
@@ -39,6 +44,11 @@ final class ResourceObjectDecodingErrorTests: XCTestCase {
                     location: .relationships
                 )
             )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'required' relationship is required and missing."
+            )
         }
     }
 
@@ -55,6 +65,11 @@ final class ResourceObjectDecodingErrorTests: XCTestCase {
                     location: .relationships
                 )
             )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'required' relationship is not nullable but null."
+            )
         }
     }
 
@@ -71,6 +86,11 @@ final class ResourceObjectDecodingErrorTests: XCTestCase {
                     location: .relationships
                 )
             )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'required' relationship is not nullable but null."
+            )
         }
     }
 
@@ -88,13 +108,146 @@ final class ResourceObjectDecodingErrorTests: XCTestCase {
                     location: .relationships
                 )
             )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                #"'required' relationship is of JSON:API type "not_the_same" but it was expected to be "thirteenth_test_entities""#
+            )
         }
     }
+
+    func test_twoOneVsToMany_relationship() {
+        // TODO: write test
+    }
 }
 
 // MARK: - Attributes
 extension ResourceObjectDecodingErrorTests {
-    // TODO: write tests
+    func test_missingAttributesObject() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_attributes_entirely_missing
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: ResourceObjectDecodingError.entireObject,
+                    cause: .keyNotFound,
+                    location: .attributes
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "attributes object is required and missing."
+            )
+        }
+    }
+
+    func test_required_attribute() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_required_attribute_is_omitted
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "required",
+                    cause: .keyNotFound,
+                    location: .attributes
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'required' attribute is required and missing."
+            )
+        }
+    }
+
+    func test_NonNullable_attribute() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_nonNullable_attribute_is_null
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "required",
+                    cause: .valueNotFound,
+                    location: .attributes
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'required' attribute is not nullable but null."
+            )
+        }
+    }
+
+    func test_oneTypeVsAnother_attribute() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_attribute_is_wrong_type
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "required",
+                    cause: .typeMismatch(expectedTypeName: String(describing: String.self)),
+                    location: .attributes
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'required' attribute is not a String as expected."
+            )
+        }
+    }
+
+    func test_oneTypeVsAnother_attribute2() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_attribute_is_wrong_type2
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "other",
+                    cause: .typeMismatch(expectedTypeName: String(describing: Int.self)),
+                    location: .attributes
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'other' attribute is not a Int as expected."
+            )
+        }
+    }
+
+    func test_oneTypeVsAnother_attribute3() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_attribute_is_wrong_type3
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "yetAnother",
+                    cause: .typeMismatch(expectedTypeName: String(describing: Bool.self)),
+                    location: .attributes
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'yetAnother' attribute is not a Bool as expected."
+            )
+        }
+    }
 }
 
 // MARK: - Test Types
@@ -111,4 +264,19 @@ extension ResourceObjectDecodingErrorTests {
     }
 
     typealias TestEntity = BasicEntity<TestEntityType>
+
+    enum TestEntityType2: ResourceObjectDescription {
+        public static var jsonType: String { return "thirteenth_test_entities" }
+
+        public struct Attributes: JSONAPI.Attributes {
+
+            let required: Attribute<String>
+            let other: Attribute<Int>?
+            let yetAnother: Attribute<Bool?>?
+        }
+
+        typealias Relationships = NoRelationships
+    }
+
+    typealias TestEntity2 = BasicEntity<TestEntityType2>
 }

Tests/JSONAPITests/ResourceObject/stubs/ResourceObjectStubs.swift

@@ -446,6 +446,64 @@ let entity_relationships_entirely_missing = """
 }
 """.data(using: .utf8)!
 
+let entity_required_attribute_is_omitted = """
+{
+    "id": "1",
+    "type": "thirteenth_test_entities",
+    "attributes": {
+    }
+}
+""".data(using: .utf8)!
+
+let entity_nonNullable_attribute_is_null = """
+{
+    "id": "1",
+    "type": "thirteenth_test_entities",
+    "attributes": {
+        "required": null
+    }
+}
+""".data(using: .utf8)!
+
+let entity_attribute_is_wrong_type = """
+{
+    "id": "1",
+    "type": "thirteenth_test_entities",
+    "attributes": {
+        "required": 10
+    }
+}
+""".data(using: .utf8)!
+
+let entity_attribute_is_wrong_type2 = """
+{
+    "id": "1",
+    "type": "thirteenth_test_entities",
+    "attributes": {
+        "required": "hello",
+        "other": "world"
+    }
+}
+""".data(using: .utf8)!
+
+let entity_attribute_is_wrong_type3 = """
+{
+    "id": "1",
+    "type": "thirteenth_test_entities",
+    "attributes": {
+        "required": "hello",
+        "yetAnother": 101
+    }
+}
+""".data(using: .utf8)!
+
+let entity_attributes_entirely_missing = """
+{
+    "id": "1",
+    "type": "thirteenth_test_entities"
+}
+""".data(using: .utf8)!
+
 let entity_unidentified = """
 {
 	"type": "unidentified_test_entities",