Update OpenAPIKit to v6

Package.swift

@@ -46,7 +46,7 @@ let package = Package(
         .package(url: "https://github.com/apple/swift-collections", from: "1.1.4"),
 
         // Read OpenAPI documents
-        .package(url: "https://github.com/mattpolzin/OpenAPIKit", from: "3.9.0"),
+        .package(url: "https://github.com/mattpolzin/OpenAPIKit", from: "6.0.0", traits: []),
         .package(url: "https://github.com/jpsim/Yams", "4.0.0"..<"7.0.0"),
 
         // CLI Tool
@@ -165,4 +165,4 @@ for target in package.targets {
     case .macro, .plugin, .system, .binary: ()  // not applicable
     @unknown default: ()  // we don't know what to do here, do nothing
     }
-}// --- END: STANDARD CROSS-REPO SETTINGS DO NOT EDIT --- //
+}  // --- END: STANDARD CROSS-REPO SETTINGS DO NOT EDIT --- //

Sources/_OpenAPIGeneratorCore/Extensions/OpenAPIKit.swift

@@ -22,12 +22,42 @@ extension Either {
     /// - Throws: An error if there's an issue looking up the value in the components.
     func resolve(in components: OpenAPI.Components) throws -> B where A == OpenAPI.Reference<B> {
         switch self {
-        case let .a(a): return try components.lookup(a)
+        case let .a(a): return try components.assumeLookupOnce(a)
         case let .b(b): return b
         }
     }
 }
 
+extension OpenAPI.Components {
+    func assumeLookupOnce<ReferenceType: ComponentDictionaryLocatable>(_ reference: OpenAPI.Reference<ReferenceType>)
+        throws -> ReferenceType
+    {
+        guard let result = try lookupOnce(reference).b else {
+            throw JSONReferenceParsingError.componentsReferenceEntryUnsupported(reference.absoluteString)
+        }
+        return result
+    }
+
+    func assumeLookupOnce<ReferenceType: ComponentDictionaryLocatable>(_ reference: JSONReference<ReferenceType>) throws
+        -> ReferenceType
+    {
+        guard let result = try lookupOnce(reference).b else {
+            throw JSONReferenceParsingError.componentsReferenceEntryUnsupported(reference.absoluteString)
+        }
+        return result
+    }
+
+    func assumeLookupOnce<ReferenceType: ComponentDictionaryLocatable>(
+        _ maybeReference: Either<OpenAPI.Reference<ReferenceType>, ReferenceType>
+    ) throws -> ReferenceType {
+        guard let result = try lookupOnce(maybeReference).b else {
+            throw JSONReferenceParsingError.componentsReferenceEntryUnsupported(maybeReference.a?.absoluteString)
+        }
+        return result
+    }
+
+}
+
 extension JSONSchema.Schema {
 
     /// Returns the name of the schema.

Sources/_OpenAPIGeneratorCore/Hooks/FilteredDocument.swift

@@ -103,8 +103,8 @@ struct FilteredDocumentBuilder {
             guard let methods = requiredEndpoints[path] else { continue }
             switch pathItem {
             case .a(let reference):
-                components.pathItems[try reference.internalComponentKey] = try document.components.lookup(reference)
-                    .filteringEndpoints { methods.contains($0.method) }
+                components.pathItems[try reference.internalComponentKey] = try document.components
+                    .assumeLookupOnce(reference).filteringEndpoints { methods.contains($0.method) }
             case .b(let pathItem):
                 filteredDocument.paths[path] = .b(pathItem.filteringEndpoints { methods.contains($0.method) })
             }
@@ -169,7 +169,7 @@ struct FilteredDocumentBuilder {
     /// - Parameter name: The key in the `#/components/schemas` map in the OpenAPI document.
     /// - Throws: If the named schema does not exist in original OpenAPI document.
     mutating func includeSchema(_ name: String) throws {
-        try includeSchema(.a(OpenAPI.Reference<JSONSchema>.component(named: name)))
+        try includeComponentsReferencedBy(.reference(.component(named: name)))
     }
 }
 
@@ -198,16 +198,7 @@ private extension FilteredDocumentBuilder {
         switch maybeReference {
         case .a(let reference):
             guard try requiredPathItemReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
-        case .b(let value): try includeComponentsReferencedBy(value)
-        }
-    }
-
-    mutating func includeSchema(_ maybeReference: Either<OpenAPI.Reference<JSONSchema>, JSONSchema>) throws {
-        switch maybeReference {
-        case .a(let reference):
-            guard try requiredSchemaReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
+            try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
         case .b(let value): try includeComponentsReferencedBy(value)
         }
     }
@@ -218,7 +209,7 @@ private extension FilteredDocumentBuilder {
         switch maybeReference {
         case .a(let reference):
             guard try requiredParameterReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
+            try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
         case .b(let value): try includeComponentsReferencedBy(value)
         }
     }
@@ -229,7 +220,7 @@ private extension FilteredDocumentBuilder {
         switch maybeReference {
         case .a(let reference):
             guard try requiredResponseReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
+            try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
         case .b(let value): try includeComponentsReferencedBy(value)
         }
     }
@@ -238,7 +229,7 @@ private extension FilteredDocumentBuilder {
         switch maybeReference {
         case .a(let reference):
             guard try requiredHeaderReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
+            try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
         case .b(let value): try includeComponentsReferencedBy(value)
         }
     }
@@ -247,7 +238,7 @@ private extension FilteredDocumentBuilder {
         switch maybeReference {
         case .a(let reference):
             guard try requiredLinkReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
+            try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
         case .b(let value): try includeComponentsReferencedBy(value)
         }
     }
@@ -258,7 +249,7 @@ private extension FilteredDocumentBuilder {
         switch maybeReference {
         case .a(let reference):
             guard try requiredCallbacksReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
+            try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
         case .b(let value): try includeComponentsReferencedBy(value)
         }
     }
@@ -269,7 +260,7 @@ private extension FilteredDocumentBuilder {
         switch maybeReference {
         case .a(let reference):
             guard try requiredRequestReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
+            try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
         case .b(let value): try includeComponentsReferencedBy(value)
         }
     }
@@ -278,7 +269,7 @@ private extension FilteredDocumentBuilder {
         switch maybeReference {
         case .a(let reference):
             guard try requiredExampleReferences.insert(reference.internalComponentKey).inserted else { return }
-            try includeComponentsReferencedBy(try document.components.lookup(reference))
+            try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
         case .b(let value): try includeComponentsReferencedBy(value)
         }
     }
@@ -287,7 +278,7 @@ private extension FilteredDocumentBuilder {
         for (path, maybePathItemReference) in document.paths {
             let originalPathItem: OpenAPI.PathItem
             switch maybePathItemReference {
-            case .a(let reference): originalPathItem = try document.components.lookup(reference)
+            case .a(let reference): originalPathItem = try document.components.assumeLookupOnce(reference)
             case .b(let pathItem): originalPathItem = pathItem
             }
 
@@ -330,7 +321,7 @@ private extension FilteredDocumentBuilder {
         case .reference(let reference, _):
             let referenceKey = try OpenAPI.ComponentKey(stringLiteral: reference.requiredName)
             guard requiredSchemaReferences.insert(referenceKey).inserted else { return }
-            try includeComponentsReferencedBy(document.components.lookup(reference))
+            try includeComponentsReferencedBy(document.components.lookupOnce(reference).flattenToJsonSchema())
 
         case .object(_, let object):
             for schema in object.properties.values { try includeComponentsReferencedBy(schema) }
@@ -362,20 +353,22 @@ private extension FilteredDocumentBuilder {
             switch schemaContext.schema {
             case .a(let reference):
                 guard try requiredSchemaReferences.insert(reference.internalComponentKey).inserted else { return }
-                try includeComponentsReferencedBy(try document.components.lookup(reference))
+                try includeComponentsReferencedBy(try document.components.assumeLookupOnce(reference))
             case .b(let schema): try includeComponentsReferencedBy(schema)
             }
-        case .b(let contentMap):
-            for value in contentMap.values {
-                switch value.schema {
-                case .a(let reference):
-                    guard try requiredSchemaReferences.insert(reference.internalComponentKey).inserted else { return }
-                    try includeComponentsReferencedBy(try document.components.lookup(reference))
-                case .b(let schema): try includeComponentsReferencedBy(schema)
-                case .none: continue
-                }
-            }
+        case .b(let contentMap): for value in contentMap.values { try includeComponentsReferencedBy(value) }
+        }
+    }
+
+    mutating func includeComponentsReferencedBy(
+        _ contentMapEntry: Either<OpenAPI.Reference<OpenAPI.Content>, OpenAPI.Content>
+    ) throws {
+        let content: OpenAPI.Content
+        switch contentMapEntry {
+        case .a(let ref): content = try document.components.assumeLookupOnce(ref)
+        case .b(let value): content = value
         }
+        try includeComponentsReferencedBy(content)
     }
 
     mutating func includeComponentsReferencedBy(_ response: OpenAPI.Response) throws {
@@ -385,8 +378,8 @@ private extension FilteredDocumentBuilder {
     }
 
     mutating func includeComponentsReferencedBy(_ content: OpenAPI.Content) throws {
-        if let schema = content.schema { try includeSchema(schema) }
-        if let encoding = content.encoding {
+        if let schema = content.schema { try includeComponentsReferencedBy(schema) }
+        if let encoding = content.encodingMap {
             for encoding in encoding.values {
                 if let headers = encoding.headers { for header in headers.values { try includeHeader(header) } }
             }

Sources/_OpenAPIGeneratorCore/Parser/YamsParser.swift

@@ -54,13 +54,6 @@ public struct YamsParser: ParserProtocol {
         let decoder = YAMLDecoder()
         let openapiData = input.contents
 
-        let decodingOptions = [
-            DocumentConfiguration.versionMapKey: [
-                // Until we move to OpenAPIKit v5.0+ we will parse OAS 3.2.0 as if it were OAS 3.1.2
-                "3.2.0": OpenAPI.Document.Version.v3_1_2
-            ]
-        ]
-
         struct OpenAPIVersionedDocument: Decodable { var openapi: String? }
 
         let versionedDocument: OpenAPIVersionedDocument
@@ -82,12 +75,7 @@ public struct YamsParser: ParserProtocol {
                 document = openAPI30Document.convert(to: .v3_1_0)
             case "3.1.0", "3.1.1", "3.1.2":
                 document = try decoder.decode(OpenAPIKit.OpenAPI.Document.self, from: input.contents)
-            case "3.2.0":
-                document = try decoder.decode(
-                    OpenAPIKit.OpenAPI.Document.self,
-                    from: input.contents,
-                    userInfo: decodingOptions
-                )
+            case "3.2.0": document = try decoder.decode(OpenAPIKit.OpenAPI.Document.self, from: input.contents)
             default:
                 throw Diagnostic.openAPIVersionError(
                     versionString: "openapi: \(openAPIVersion)",

Sources/_OpenAPIGeneratorCore/Parser/validateDoc.swift

@@ -67,6 +67,7 @@ func validateContentTypes(in doc: ParsedOpenAPIRepresentation, validate: (String
     }
 
     for (key, component) in doc.components.requestBodies {
+        let component = try doc.components.assumeLookupOnce(component)
         for contentType in component.content.keys {
             if !validate(contentType.rawValue) {
                 throw Diagnostic.error(
@@ -81,6 +82,7 @@ func validateContentTypes(in doc: ParsedOpenAPIRepresentation, validate: (String
     }
 
     for (key, component) in doc.components.responses {
+        let component = try doc.components.assumeLookupOnce(component)
         for contentType in component.content.keys {
             if !validate(contentType.rawValue) {
                 throw Diagnostic.error(
@@ -124,21 +126,26 @@ func validateReferences(in doc: ParsedOpenAPIRepresentation) throws {
 
     func validateReferencesInContentTypes(_ content: OpenAPI.Content.Map, location: String) throws {
         for (contentKey, contentType) in content {
-            if let reference = contentType.schema?.reference {
-                try validateReference(
-                    reference,
-                    in: doc.components,
-                    location: location + "/content/\(contentKey.rawValue)/schema"
-                )
-            }
-            if let eitherExamples = contentType.examples?.values {
-                for example in eitherExamples {
-                    if let reference = example.reference {
-                        try validateReference(
-                            reference,
-                            in: doc.components,
-                            location: location + "/content/\(contentKey.rawValue)/examples"
-                        )
+            switch contentType {
+            case .a(let ref):
+                try validateReference(ref, in: doc.components, location: location + "/content/\(contentKey.rawValue)")
+            case .b(let contentType):
+                if let reference: JSONReference<JSONSchema> = contentType.schema?.reference {
+                    try validateReference(
+                        .init(reference),
+                        in: doc.components,
+                        location: location + "/content/\(contentKey.rawValue)/schema"
+                    )
+                }
+                if let eitherExamples = contentType.examples?.values {
+                    for example in eitherExamples {
+                        if let reference = example.reference {
+                            try validateReference(
+                                reference,
+                                in: doc.components,
+                                location: location + "/content/\(contentKey.rawValue)/examples"
+                            )
+                        }
                     }
                 }
             }

Sources/_OpenAPIGeneratorCore/Translator/CommonTranslations/translateRawEnum.swift

@@ -100,7 +100,9 @@ extension FileTranslator {
                 // In nullable enum schemas, empty strings are parsed as Void.
                 // This is unlikely to be fixed, so handling that case here.
                 // https://github.com/apple/swift-openapi-generator/issues/118
-                if isNullable && anyValue is Void {
+                // Also handle nil values in nullable schemas.
+                let isNullValue = anyValue is Void || (anyValue as? String) == nil
+                if isNullable && isNullValue {
                     try addIfUnique(id: .string(""), caseName: context.safeNameGenerator.swiftMemberName(for: ""))
                 } else {
                     guard let rawValue = anyValue as? String else {

Sources/_OpenAPIGeneratorCore/Translator/Content/ContentInspector.swift

@@ -97,7 +97,7 @@ extension FileTranslator {
         return try contents.compactMap { key, value in
             try parseContentIfSupported(
                 contentKey: key,
-                contentValue: value,
+                contentValue: try components.assumeLookupOnce(value),
                 excludeBinary: excludeBinary,
                 isRequired: isRequired,
                 foundIn: foundIn + "/\(key.rawValue)"
@@ -129,12 +129,17 @@ extension FileTranslator {
 
         let chosenContent: (type: ContentType, schema: SchemaContent, content: OpenAPI.Content)?
         if let (contentType, contentValue) = mapWithContentTypes.first(where: { $0.type.isJSON }) {
-            chosenContent = (contentType, .init(contentType: contentType, schema: contentValue.schema), contentValue)
+            let contentValue = try components.assumeLookupOnce(contentValue)
+            chosenContent = (
+                contentType, .init(contentType: contentType, schema: contentValue.schema.map(Either.schema)),
+                contentValue
+            )
         } else if !excludeBinary,
             let (contentType, contentValue) = mapWithContentTypes.first(where: { $0.type.isBinary })
         {
+            let contentValue = try components.assumeLookupOnce(contentValue)
             chosenContent = (
-                contentType, .init(contentType: contentType, schema: .b(.string(contentEncoding: .binary))),
+                contentType, .init(contentType: contentType, schema: .schema(.string(contentEncoding: .binary))),
                 contentValue
             )
         } else {
@@ -188,8 +193,10 @@ extension FileTranslator {
                 foundIn: "\(foundIn), content \(contentType.originallyCasedTypeAndSubtype)"
             )
         }
-        if contentType.isJSON { return .init(contentType: contentType, schema: contentValue.schema) }
-        if contentType.isUrlEncodedForm { return .init(contentType: contentType, schema: contentValue.schema) }
+        if contentType.isJSON { return .init(contentType: contentType, schema: contentValue.schema.map(Either.schema)) }
+        if contentType.isUrlEncodedForm {
+            return .init(contentType: contentType, schema: contentValue.schema.map(Either.schema))
+        }
         if contentType.isMultipart {
             guard isRequired else {
                 try diagnostics.emit(
@@ -201,10 +208,14 @@ extension FileTranslator {
                 )
                 return nil
             }
-            return .init(contentType: contentType, schema: contentValue.schema, encoding: contentValue.encoding)
+            return .init(
+                contentType: contentType,
+                schema: contentValue.schema.map(Either.schema),
+                encoding: contentValue.encodingMap
+            )
         }
         if !excludeBinary, contentType.isBinary {
-            return .init(contentType: contentType, schema: .b(.string(contentEncoding: .binary)))
+            return .init(contentType: contentType, schema: .schema(.string(contentEncoding: .binary)))
         }
         try diagnostics.emitUnsupported("Unsupported content", foundIn: foundIn)
         return nil