[Generator] Multiple content types support

.swift-format

@@ -43,7 +43,7 @@
     "OnlyOneTrailingClosureArgument" : true,
     "OrderedImports" : false,
     "ReturnVoidInsteadOfEmptyTuple" : true,
-    "UseEarlyExits" : true,
+    "UseEarlyExits" : false,
     "UseLetInEveryBoundCaseVariable" : false,
     "UseShorthandTypeNames" : true,
     "UseSingleLinePropertyGetter" : false,

Package.swift

@@ -143,6 +143,18 @@ let package = Package(
             swiftSettings: swiftSettings
         ),
 
+        // PetstoreConsumerTestsFFMultipleContentTypes
+        // Builds and tests the reference code from GeneratorReferenceTests
+        // to ensure it actually works correctly at runtime.
+        // Enabled feature flag: multipleContentTypes
+        .testTarget(
+            name: "PetstoreConsumerTestsFFMultipleContentTypes",
+            dependencies: [
+                "PetstoreConsumerTestCore"
+            ],
+            swiftSettings: swiftSettings
+        ),
+
         // Generator CLI
         .executableTarget(
             name: "swift-openapi-generator",

Sources/_OpenAPIGeneratorCore/Layers/StructuredSwiftRepresentation.swift

@@ -664,6 +664,38 @@ struct SwitchDescription: Equatable, Codable {
     var cases: [SwitchCaseDescription]
 }
 
+/// A description of an if condition and the corresponding code block.
+///
+/// For example: in `if foo { bar }`, the condition pair represents
+/// `foo` + `bar`.
+struct IfConditionPair: Equatable, Codable {
+
+    /// The expressions evaluated by the if statement and their corresponding
+    /// body blocks. If more than one is provided, an `else if` branch is added.
+    ///
+    /// For example, in `if foo { bar }`, `condition` is `foo`.
+    var condition: Expression
+
+    /// The body executed if the `condition` evaluates to true.
+    ///
+    /// For example, in `if foo { bar }`, `body` is `bar`.
+    var body: [CodeBlock]
+}
+
+/// A description of an if[[/elseif]/else] statement expression.
+///
+/// For example: `if foo { } else if bar { } else { }`.
+struct IfStatementDescription: Equatable, Codable {
+
+    /// The conditional branches.
+    var branches: [IfConditionPair]
+
+    /// The body of an else block.
+    ///
+    /// No `else` statement is added when `elseBody` is nil.
+    var elseBody: [CodeBlock]?
+}
+
 /// A description of a do statement.
 ///
 /// For example: `do { try foo() } catch { return bar }`.
@@ -709,6 +741,9 @@ enum KeywordKind: Equatable, Codable {
 
     /// The await keyword.
     case `await`
+
+    /// The throw keyword.
+    case `throw`
 }
 
 /// A description of an expression that places a keyword before an expression.
@@ -751,8 +786,14 @@ enum BinaryOperator: String, Equatable, Codable {
     /// The += operator, adds and then assigns another value.
     case plusEquals = "+="
 
+    /// The == operator, checks equality between two values.
+    case equals = "=="
+
     /// The ... operator, creates an end-inclusive range between two numbers.
     case rangeInclusive = "..."
+
+    /// The || operator, used between two Boolean values.
+    case booleanOr = "||"
 }
 
 /// A description of a binary operation expression.
@@ -832,6 +873,11 @@ indirect enum Expression: Equatable, Codable {
     /// For example: `switch foo {`.
     case `switch`(SwitchDescription)
 
+    /// An if statement, with optional else if's and an else statement attached.
+    ///
+    /// For example: `if foo { bar } else if baz { boo } else { bam }`.
+    case ifStatement(IfStatementDescription)
+
     /// A do statement.
     ///
     /// For example: `do { try foo() } catch { return bar }`.
@@ -1202,6 +1248,23 @@ extension Expression {
         )
     }
 
+    /// Returns an if statement, with optional else if's and an else
+    /// statement attached.
+    /// - Parameters:
+    ///   - branches: The conditional branches.
+    ///   - elseBody: The body of an else block.
+    static func ifStatement(
+        branches: [IfConditionPair],
+        elseBody: [CodeBlock]? = nil
+    ) -> Self {
+        .ifStatement(
+            .init(
+                branches: branches,
+                elseBody: elseBody
+            )
+        )
+    }
+
     /// Returns a new function call expression.
     ///
     /// For example `foo(bar: 42)`.

Sources/_OpenAPIGeneratorCore/Renderer/TextBasedRenderer.swift

@@ -173,6 +173,28 @@ struct TextBasedRenderer: RendererProtocol {
         return lines.joinedLines()
     }
 
+    /// Renders the specified if statement.
+    func renderedIf(_ ifDesc: IfStatementDescription) -> String {
+        var branches = ifDesc.branches
+        precondition(!branches.isEmpty, "Cannot have an if statement with no branches.")
+        var lines: [String] = []
+        let firstCondition = branches.removeFirst()
+        lines.append("if \(renderedExpression(firstCondition.condition)) {")
+        lines.append(renderedCodeBlocks(firstCondition.body))
+        lines.append("}")
+        for branch in branches {
+            lines.append("else if \(renderedExpression(branch.condition)) {")
+            lines.append(renderedCodeBlocks(branch.body))
+            lines.append("}")
+        }
+        if let elseBody = ifDesc.elseBody {
+            lines.append("else {")
+            lines.append(renderedCodeBlocks(elseBody))
+            lines.append("}")
+        }
+        return lines.joinedLines()
+    }
+
     /// Renders the specified switch expression.
     func renderedDoStatement(_ description: DoStatementDescription) -> String {
         var lines: [String] = ["do {"]
@@ -199,6 +221,8 @@ struct TextBasedRenderer: RendererProtocol {
             return "try\(hasPostfixQuestionMark ? "?" : "")"
         case .await:
             return "await"
+        case .throw:
+            return "throw"
         }
     }
 
@@ -266,6 +290,8 @@ struct TextBasedRenderer: RendererProtocol {
             return renderedAssignment(assignment)
         case .switch(let switchDesc):
             return renderedSwitch(switchDesc)
+        case .ifStatement(let ifDesc):
+            return renderedIf(ifDesc)
         case .doStatement(let doStmt):
             return renderedDoStatement(doStmt)
         case .valueBinding(let valueBinding):

Sources/_OpenAPIGeneratorCore/Translator/Content/ContentInspector.swift

@@ -61,6 +61,78 @@ extension FileTranslator {
         return .init(content: content, typeUsage: associatedType)
     }
 
+    /// Extract the supported content types.
+    /// - Parameters:
+    ///   - map: The content map from the OpenAPI document.
+    ///   - excludeBinary: A Boolean value controlling whether binary content
+    ///   type should be skipped, for example used when encoding headers.
+    ///   - parent: The parent type of the chosen typed schema.
+    /// - Returns: The supported content type + schema + type names.
+    func supportedTypedContents(
+        _ map: OpenAPI.Content.Map,
+        excludeBinary: Bool = false,
+        inParent parent: TypeName
+    ) throws -> [TypedSchemaContent] {
+        let contents = supportedContents(
+            map,
+            excludeBinary: excludeBinary,
+            foundIn: parent.description
+        )
+        return try contents.compactMap { content in
+            guard
+                try validateSchemaIsSupported(
+                    content.schema,
+                    foundIn: parent.description
+                )
+            else {
+                return nil
+            }
+            let identifier = contentSwiftName(content.contentType)
+            let associatedType = try typeAssigner.typeUsage(
+                usingNamingHint: identifier,
+                withSchema: content.schema,
+                inParent: parent
+            )
+            return .init(content: content, typeUsage: associatedType)
+        }
+    }
+
+    /// Extract the supported content types.
+    /// - Parameters:
+    ///   - contents: The content map from the OpenAPI document.
+    ///   - excludeBinary: A Boolean value controlling whether binary content
+    ///   type should be skipped, for example used when encoding headers.
+    ///   - foundIn: The location where this content is parsed.
+    /// - Returns: the detected content type + schema, nil if no supported
+    /// schema found or if empty.
+    func supportedContents(
+        _ contents: OpenAPI.Content.Map,
+        excludeBinary: Bool = false,
+        foundIn: String
+    ) -> [SchemaContent] {
+        guard !contents.isEmpty else {
+            return []
+        }
+        guard config.featureFlags.contains(.multipleContentTypes) else {
+            return bestSingleContent(
+                contents,
+                excludeBinary: excludeBinary,
+                foundIn: foundIn
+            )
+            .flatMap { [$0] } ?? []
+        }
+        return
+            contents
+            .compactMap { key, value in
+                parseContentIfSupported(
+                    contentKey: key,
+                    contentValue: value,
+                    excludeBinary: excludeBinary,
+                    foundIn: foundIn + "/\(key.rawValue)"
+                )
+            }
+    }
+
     /// While we only support a single content at a time, choose the best one.
     ///
     /// Priority:
@@ -72,6 +144,7 @@ extension FileTranslator {
     ///   - map: The content map from the OpenAPI document.
     ///   - excludeBinary: A Boolean value controlling whether binary content
     ///   type should be skipped, for example used when encoding headers.
+    ///   - foundIn: The location where this content is parsed.
     /// - Returns: the detected content type + schema, nil if no supported
     /// schema found or if empty.
     func bestSingleContent(
@@ -123,4 +196,62 @@ extension FileTranslator {
             return nil
         }
     }
+
+    /// Returns a wrapped version of the provided content if supported, returns
+    /// nil otherwise.
+    ///
+    /// Priority of checking for known MIME types:
+    /// 1. JSON
+    /// 2. text
+    /// 3. binary
+    ///
+    /// - Parameters:
+    ///   - contentKey: The content key from the OpenAPI document.
+    ///   - contentValue: The content value from the OpenAPI document.
+    ///   - excludeBinary: A Boolean value controlling whether binary content
+    ///   type should be skipped, for example used when encoding headers.
+    ///   - foundIn: The location where this content is parsed.
+    /// - Returns: The detected content type + schema, nil if unsupported.
+    func parseContentIfSupported(
+        contentKey: OpenAPI.ContentType,
+        contentValue: OpenAPI.Content,
+        excludeBinary: Bool = false,
+        foundIn: String
+    ) -> SchemaContent? {
+        if contentKey.isJSON,
+            let contentType = ContentType(contentKey.typeAndSubtype)
+        {
+            diagnostics.emitUnsupportedIfNotNil(
+                contentValue.encoding,
+                "Custom encoding for JSON content",
+                foundIn: "\(foundIn), content \(contentKey.rawValue)"
+            )
+            return .init(
+                contentType: contentType,
+                schema: contentValue.schema
+            )
+        }
+        if contentKey.isText,
+            let contentType = ContentType(contentKey.typeAndSubtype)
+        {
+            return .init(
+                contentType: contentType,
+                schema: .b(.string)
+            )
+        }
+        if !excludeBinary,
+            contentKey.isBinary,
+            let contentType = ContentType(contentKey.typeAndSubtype)
+        {
+            return .init(
+                contentType: contentType,
+                schema: .b(.string(format: .binary))
+            )
+        }
+        diagnostics.emitUnsupported(
+            "Unsupported content",
+            foundIn: foundIn
+        )
+        return nil
+    }
 }

Sources/_OpenAPIGeneratorCore/Translator/Content/ContentSwiftName.swift

@@ -21,7 +21,25 @@ extension FileTranslator {
     /// - Parameter contentType: The content type for which to compute the name.
     func contentSwiftName(_ contentType: ContentType) -> String {
         if config.featureFlags.contains(.multipleContentTypes) {
-            return "unsupported"
+            let rawMIMEType = contentType.rawMIMEType
+            switch rawMIMEType {
+            case "application/json":
+                return "json"
+            case "application/x-www-form-urlencoded":
+                return "form"
+            case "multipart/form-data":
+                return "multipart"
+            case "text/plain":
+                return "text"
+            case "*/*":
+                return "any"
+            case "application/xml":
+                return "xml"
+            case "application/octet-stream":
+                return "binary"
+            default:
+                return swiftSafeName(for: rawMIMEType)
+            }
         } else {
             switch contentType {
             case .json:

Sources/_OpenAPIGeneratorCore/Translator/Content/ContentType.swift

@@ -42,6 +42,14 @@ enum ContentType: Hashable {
         self = .binary(rawValue)
     }
 
+    /// Returns the original raw MIME type.
+    var rawMIMEType: String {
+        switch self {
+        case .json(let string), .text(let string), .binary(let string):
+            return string
+        }
+    }
+
     /// The header value used when sending a content-type header.
     var headerValueForSending: String {
         switch self {
@@ -107,23 +115,10 @@ enum ContentType: Hashable {
         }
         return false
     }
-
-    /// Returns a new content type representing an octet stream.
-    static var octetStream: Self {
-        .binary("application/octet-stream")
-    }
-
-    /// Returns a new content type representing JSON.
-    static var applicationJSON: Self {
-        .json("application/json")
-    }
 }
 
 extension OpenAPI.ContentType {
 
-    /// Returns a new content type representing an octet stream.
-    static let octetStream: Self = .other(ContentType.octetStream.headerValueForValidation)
-
     /// A Boolean value that indicates whether the content type
     /// is a type of JSON.
     var isJSON: Bool {