Skip inferred properties

Package.swift

@@ -55,7 +55,7 @@ let package = Package(
         .package(url: "https://github.com/apple/swift-algorithms", from: "1.0.0"),
 
         // Read OpenAPI documents
-        .package(url: "https://github.com/mattpolzin/OpenAPIKit.git", from: "3.0.1"),
+        .package(url: "https://github.com/mattpolzin/OpenAPIKit.git", from: "3.1.0"),
         .package(url: "https://github.com/jpsim/Yams.git", "4.0.0"..<"6.0.0"),
 
         // CLI Tool

Sources/_OpenAPIGeneratorCore/Translator/CommonTranslations/translateObjectStruct.swift

@@ -38,6 +38,20 @@ extension FileTranslator {
 
                 let foundIn = "\(typeName.description)/\(key)"
 
+                // Properties that are only defined in the `required` list but don't
+                // have a proper definition in the `properties` map are skipped, as they
+                // often imply a typo or a mistake in the document. So emit a diagnostic as well.
+                guard !value.inferred else {
+                    diagnostics.emit(
+                        .warning(
+                            message:
+                                "A property name only appears in the required list, but not in the properties map - this is likely a typo; skipping this property.",
+                            context: ["foundIn": foundIn]
+                        )
+                    )
+                    return false
+                }
+
                 // We need to catch a special case here:
                 // type: string + format: binary.
                 // It means binary data (unlike format: byte, which means base64

Tests/OpenAPIGeneratorReferenceTests/SnippetBasedReferenceTests.swift

@@ -156,6 +156,38 @@ final class SnippetBasedReferenceTests: XCTestCase {
         )
     }
 
+    func testComponentsSchemasObjectWithInferredProperty() throws {
+        try self.assertSchemasTranslation(
+            ignoredDiagnosticMessages: [
+                "A property name only appears in the required list, but not in the properties map - this is likely a typo; skipping this property."
+            ],
+            """
+            schemas:
+              MyObj:
+                type: object
+                properties:
+                  fooRequired:
+                    type: string
+                required:
+                  - fooRequired
+                  - fooInferred
+            """,
+            """
+            public enum Schemas {
+                public struct MyObj: Codable, Hashable, Sendable {
+                    public var fooRequired: Swift.String
+                    public init(fooRequired: Swift.String) {
+                        self.fooRequired = fooRequired
+                    }
+                    public enum CodingKeys: String, CodingKey {
+                        case fooRequired
+                    }
+                }
+            }
+            """
+        )
+    }
+
     func testComponentsObjectNoAdditionalProperties() throws {
         try self.assertSchemasTranslation(
             """