Add more errors for the resource object type property

Sources/JSONAPI/Document/DocumentDecodingError.swift

@@ -40,14 +40,12 @@ public enum DocumentDecodingError: Swift.Error, Equatable {
 
     private enum Location: Equatable {
         case data
-        case other
 
-        init(_ context: DecodingError.Context) {
-            if context.codingPath.contains(where: { $0.stringValue == "data" }) {
-                self = .data
-            } else {
-                self = .other
+        init?(_ context: DecodingError.Context) {
+            guard context.codingPath.contains(where: { $0.stringValue == "data" }) else {
+                return nil
             }
+            self = .data
         }
     }
 }

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

@@ -414,7 +414,13 @@ public extension ResourceObject {
     init(from decoder: Decoder) throws {
         let container = try decoder.container(keyedBy: ResourceObjectCodingKeys.self)
 
-        let type = try container.decode(String.self, forKey: .type)
+        let type: String
+        do {
+            type = try container.decode(String.self, forKey: .type)
+        } catch let error as DecodingError {
+            throw ResourceObjectDecodingError(error)
+                ?? error
+        }
 
         guard ResourceObject.jsonType == type else {
             throw ResourceObjectDecodingError(

Sources/JSONAPI/Resource/Resource Object/ResourceObjectDecodingError.swift

@@ -102,13 +102,18 @@ public struct ResourceObjectDecodingError: Swift.Error, Equatable {
 extension ResourceObjectDecodingError: CustomStringConvertible {
     public var description: String {
         switch cause {
+        case .keyNotFound where subjectName == ResourceObjectDecodingError.entireObject:
+            return "\(location) object is required and missing."
+        case .keyNotFound where location == .type:
+            return "'type' (a.k.a. JSON:API type name) is required and missing."
         case .keyNotFound:
-            if subjectName == ResourceObjectDecodingError.entireObject {
-                return "\(location) object is required and missing."
-            }
             return "'\(subjectName)' \(location.singular) is required and missing."
+        case .valueNotFound where location == .type:
+            return "'type' (a.k.a. JSON:API type name) is not nullable but null was found."
         case .valueNotFound:
-            return "'\(subjectName)' \(location.singular) is not nullable but null."
+            return "'\(subjectName)' \(location.singular) is not nullable but null was found."
+        case .typeMismatch(expectedTypeName: let expected) where location == .type:
+            return "'type' (a.k.a. the JSON:API type name) is not a \(expected) as expected."
         case .typeMismatch(expectedTypeName: let expected):
             return "'\(subjectName)' \(location.singular) is not a \(expected) as expected."
         case .jsonTypeMismatch(expectedType: let expected, foundType: let found) where location == .type:

Tests/JSONAPITestingTests/Comparisons/ResourceObjectCompareTests.swift

@@ -11,7 +11,6 @@ import JSONAPITesting
 
 final class ResourceObjectCompareTests: XCTestCase {
     func test_same() {
-        print(test1.compare(to: test1).differences)
         XCTAssertTrue(test1.compare(to: test1).differences.isEmpty)
         XCTAssertTrue(test2.compare(to: test2).differences.isEmpty)
     }

Tests/JSONAPITests/ResourceObject/ResourceObjectDecodingErrorTests.swift

@@ -68,7 +68,7 @@ final class ResourceObjectDecodingErrorTests: XCTestCase {
 
             XCTAssertEqual(
                 (error as? ResourceObjectDecodingError)?.description,
-                "'required' relationship is not nullable but null."
+                "'required' relationship is not nullable but null was found."
             )
         }
     }
@@ -89,7 +89,7 @@ final class ResourceObjectDecodingErrorTests: XCTestCase {
 
             XCTAssertEqual(
                 (error as? ResourceObjectDecodingError)?.description,
-                "'required' relationship is not nullable but null."
+                "'required' relationship is not nullable but null was found."
             )
         }
     }
@@ -99,7 +99,6 @@ final class ResourceObjectDecodingErrorTests: XCTestCase {
             TestEntity.self,
             from: entity_relationship_is_wrong_type
         )) { error in
-            print(error)
             XCTAssertEqual(
                 error as? ResourceObjectDecodingError,
                 ResourceObjectDecodingError(
@@ -218,7 +217,7 @@ extension ResourceObjectDecodingErrorTests {
 
             XCTAssertEqual(
                 (error as? ResourceObjectDecodingError)?.description,
-                "'required' attribute is not nullable but null."
+                "'required' attribute is not nullable but null was found."
             )
         }
     }
@@ -285,11 +284,44 @@ extension ResourceObjectDecodingErrorTests {
             )
         }
     }
+
+    func test_transformed_attribute() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_attribute_is_wrong_type4
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "transformed",
+                    cause: .typeMismatch(expectedTypeName: String(describing: Int.self)),
+                    location: .attributes
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                "'transformed' attribute is not a Int as expected."
+            )
+        }
+    }
+
+    func test_transformed_attribute2() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_attribute_always_fails
+        )) { error in
+            XCTAssertEqual(
+                String(describing: error),
+                "Error: Always Fails"
+            )
+        }
+    }
 }
 
 // MARK: - JSON:API Type
 extension ResourceObjectDecodingErrorTests {
-    func test_wrongType() {
+    func test_wrongJSONAPIType() {
         XCTAssertThrowsError(try testDecoder.decode(
             TestEntity2.self,
             from: entity_is_wrong_type
@@ -309,6 +341,69 @@ extension ResourceObjectDecodingErrorTests {
             )
         }
     }
+
+    func test_wrongDecodedType() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_type_is_wrong_type
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "type",
+                    cause: .typeMismatch(expectedTypeName: String(describing: String.self)),
+                    location: .type
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                #"'type' (a.k.a. the JSON:API type name) is not a String as expected."#
+            )
+        }
+    }
+
+    func test_type_missing() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_type_is_missing
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "type",
+                    cause: .keyNotFound,
+                    location: .type
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                #"'type' (a.k.a. JSON:API type name) is required and missing."#
+            )
+        }
+    }
+
+    func test_type_null() {
+        XCTAssertThrowsError(try testDecoder.decode(
+            TestEntity2.self,
+            from: entity_type_is_null
+        )) { error in
+            XCTAssertEqual(
+                error as? ResourceObjectDecodingError,
+                ResourceObjectDecodingError(
+                    subjectName: "type",
+                    cause: .valueNotFound,
+                    location: .type
+                )
+            )
+
+            XCTAssertEqual(
+                (error as? ResourceObjectDecodingError)?.description,
+                #"'type' (a.k.a. JSON:API type name) is not nullable but null was found."#
+            )
+        }
+    }
 }
 
 // MARK: - Test Types
@@ -335,10 +430,30 @@ extension ResourceObjectDecodingErrorTests {
             let required: Attribute<String>
             let other: Attribute<Int>?
             let yetAnother: Attribute<Bool?>?
+            let transformed: TransformedAttribute<Int, IntToString>?
+            let transformed2: TransformedAttribute<String, AlwaysFails>?
         }
 
         typealias Relationships = NoRelationships
     }
 
     typealias TestEntity2 = BasicEntity<TestEntityType2>
+
+    enum IntToString: Transformer {
+        static func transform(_ value: Int) throws -> String {
+            return "\(value)"
+        }
+        typealias From = Int
+        typealias To = String
+    }
+
+    enum AlwaysFails: Transformer {
+        static func transform(_ value: String) throws -> String {
+            throw Error()
+        }
+
+        struct Error: Swift.Error, CustomStringConvertible {
+            let description: String = "Error: Always Fails"
+        }
+    }
 }

Tests/JSONAPITests/ResourceObject/stubs/ResourceObjectStubs.swift

@@ -533,6 +533,35 @@ let entity_attribute_is_wrong_type3 = """
 }
 """.data(using: .utf8)!
 
+let entity_attribute_is_wrong_type4 = """
+{
+    "id": "1",
+    "type": "fourteenth_test_entities",
+    "attributes": {
+        "required": "hello",
+        "transformed": "world"
+    }
+}
+""".data(using: .utf8)!
+
+let entity_attribute_always_fails = """
+{
+    "id": "1",
+    "type": "fourteenth_test_entities",
+    "attributes": {
+        "required": "hello",
+        "transformed2": "world"
+    }
+}
+""".data(using: .utf8)!
+
+let entity_attributes_entirely_missing = """
+{
+    "id": "1",
+    "type": "fourteenth_test_entities"
+}
+""".data(using: .utf8)!
+
 let entity_is_wrong_type = """
 {
     "id": "1",
@@ -544,10 +573,32 @@ let entity_is_wrong_type = """
 }
 """.data(using: .utf8)!
 
-let entity_attributes_entirely_missing = """
+let entity_type_is_wrong_type = """
 {
     "id": "1",
-    "type": "fourteenth_test_entities"
+    "type": 10,
+    "attributes": {
+        "required": "hello"
+    }
+}
+""".data(using: .utf8)!
+
+let entity_type_is_missing = """
+{
+    "id": "1",
+    "attributes": {
+        "required": "hello"
+    }
+}
+""".data(using: .utf8)!
+
+let entity_type_is_null = """
+{
+    "id": "1",
+    "type": null,
+    "attributes": {
+        "required": "hello"
+    }
 }
 """.data(using: .utf8)!
 

Tests/JSONAPITests/SparseFields/SparseFieldEncoderTests.swift

@@ -17,7 +17,6 @@ class SparseFieldEncoderTests: XCTestCase {
         do {
             let _ = try encoder.encode(Wrapper())
         } catch let err as Wrapper.OuterFail.FailError {
-            print(err.path)
             XCTAssertEqual(err.path.first as? Wrapper.OuterFail.CodingKeys, Wrapper.OuterFail.CodingKeys.inner)
         } catch {
             XCTFail("received unexpected error during test")