RUMM-2266 Reorganise rum-models-generator package for Session Replay code generation

tools/rum-models-generator/Package.swift

@@ -11,20 +11,45 @@ let package = Package(
         .package(name: "Difference", url: "https://github.com/krzysztofzablocki/Difference.git", from: "0.5.0"),
     ],
     targets: [
+        // CLI wrapper
         .target(
             name: "rum-models-generator",
             dependencies: [
-                "RUMModelsGeneratorCore",
+                "CodeGeneration",
+                "CodeDecoration",
                 .product(name: "ArgumentParser", package: "swift-argument-parser")
-            ]),
+            ]
+        ),
+        .testTarget(
+            name: "rum-models-generatorTests",
+            dependencies: ["rum-models-generator",]
+        ),
+
+        // Product-agnostic code generator (JSON Schema -> Swift | Objc-interop)
         .target(
-            name: "RUMModelsGeneratorCore",
+            name: "CodeGeneration",
             dependencies: []
         ),
         .testTarget(
-            name: "rum-models-generator-coreTests",
-            dependencies: ["RUMModelsGeneratorCore", "Difference"],
+            name: "CodeGenerationTests",
+            dependencies: [
+                "CodeGeneration",
+                "Difference"
+            ],
             resources: [.copy("Fixtures")]
         ),
+
+        // Product-specific code decorators
+        .target(
+            name: "CodeDecoration",
+            dependencies: ["CodeGeneration"]
+        ),
+        .testTarget(
+            name: "CodeDecorationTests",
+            dependencies: [
+                "CodeDecoration",
+                "Difference"
+            ]
+        ),
     ]
 )

tools/rum-models-generator/Sources/RUMModelsGeneratorCore/RUM/RUMSwiftTypeTransformer.swift → tools/rum-models-generator/Sources/CodeDecoration/RUMCodeDecorator.swift

@@ -5,9 +5,22 @@
 */
 
 import Foundation
+import CodeGeneration
+
+/// Adjusts naming and structure of generated code for RUM.
+public class RUMCodeDecorator: CodeDecorator {
+    public init() {}
+
+    // MARK: - CodeDecorator
+
+    public func decorate(code: GeneratedCode) throws -> GeneratedCode {
+        return GeneratedCode(
+            swiftTypes: try transform(types: code.swiftTypes)
+        )
+    }
+
+    // MARK: - Internal
 
-/// Transforms `SwiftTypes` for RUM code generation.
-internal class RUMSwiftTypeTransformer {
     /// Types which will shared between all input `types`. Sharing means detaching those types from nested declaration
     /// and putting them at the root level of the resultant `types` array, so the type can be printed without being nested.
     private let sharedTypeNames = [
@@ -269,3 +282,28 @@ internal class RUMSwiftTypeTransformer {
         return SwiftTypeReference(referencedTypeName: name)
     }
 }
+
+// MARK: - Utilities
+
+extension String {
+    private var camelCased: String {
+        guard !isEmpty else {
+            return ""
+        }
+
+        let words = components(separatedBy: CharacterSet.alphanumerics.inverted)
+        let first = words.first! // swiftlint:disable:this force_unwrapping
+        let rest = words.dropFirst().map { $0.uppercasingFirst }
+        return ([first] + rest).joined(separator: "")
+    }
+
+    /// Uppercases the first character.
+    var uppercasingFirst: String { prefix(1).uppercased() + dropFirst() }
+    /// Lowercases the first character.
+    var lowercasingFirst: String { prefix(1).lowercased() + dropFirst() }
+
+    /// "lowerCamelCased" notation.
+    var lowerCamelCased: String { camelCased.lowercasingFirst }
+    /// "UpperCamelCased" notation.
+    var upperCamelCased: String { camelCased.uppercasingFirst }
+}

tools/rum-models-generator/Sources/CodeDecoration/SRCodeDecorator.swift

@@ -0,0 +1,19 @@
+/*
+ * Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+ * This product includes software developed at Datadog (https://www.datadoghq.com/).
+ * Copyright 2019-2020 Datadog, Inc.
+ */
+
+import Foundation
+import CodeGeneration
+
+/// Adjusts naming and structure of generated code for Session Replay.
+public class SRCodeDecorator: CodeDecorator {
+    public init() {}
+
+    // MARK: - CodeDecorator
+
+    public func decorate(code: GeneratedCode) throws -> GeneratedCode {
+        return code // RUMM-2266 Implement actual decoration
+    }
+}

tools/rum-models-generator/Sources/CodeGeneration/Generate/Transformers/Swift/SwiftType.swift

@@ -0,0 +1,168 @@
+/*
+* Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+* This product includes software developed at Datadog (https://www.datadoghq.com/).
+* Copyright 2019-2020 Datadog, Inc.
+*/
+
+import Foundation
+
+/// Type-safe Swift schema.
+public protocol SwiftType {}
+
+/// Swift primitive type.
+public protocol SwiftPrimitiveType: SwiftType {}
+/// An allowed value of Swift primitive type.
+public protocol SwiftPrimitiveValue {}
+/// An allowed default value of Swift property.
+public protocol SwiftPropertyDefaultValue {}
+/// An allowed value of Swift with no obj-c interoperability.
+public protocol SwiftPrimitiveNoObjcInteropType: SwiftPrimitiveType {}
+
+extension Bool: SwiftPrimitiveValue, SwiftPropertyDefaultValue {}
+extension Int: SwiftPrimitiveValue, SwiftPropertyDefaultValue {}
+extension Int64: SwiftPrimitiveValue, SwiftPropertyDefaultValue {}
+extension String: SwiftPrimitiveValue, SwiftPropertyDefaultValue {}
+extension Double: SwiftPrimitiveValue, SwiftPropertyDefaultValue {}
+
+/// Represents `Swift.Codable` - we need to define utility type because it cannot be declared as `extension` to `Codable`.
+public struct SwiftCodable: SwiftPrimitiveNoObjcInteropType {}
+
+/// Represents `Swift.Encodable` - we need to define utility type because it cannot be declared as `extension` to `Encodable`.
+public struct SwiftEncodable: SwiftPrimitiveNoObjcInteropType {}
+
+public struct SwiftPrimitive<T: SwiftPrimitiveValue>: SwiftPrimitiveType {
+    public init() {}
+}
+
+public struct SwiftArray: SwiftType {
+    public var element: SwiftType
+}
+
+public struct SwiftDictionary: SwiftType {
+    public let key = SwiftPrimitive<String>()
+    public var value: SwiftPrimitiveType
+}
+
+/// An `enum` with raw-type cases.
+public struct SwiftEnum: SwiftType {
+    public struct Case: SwiftType, SwiftPropertyDefaultValue {
+        public enum RawValue {
+            case string(value: String)
+            case integer(value: Int)
+        }
+        public var label: String
+        public var rawValue: RawValue
+    }
+
+    public var name: String
+    public var comment: String?
+    public var cases: [Case]
+    public var conformance: [SwiftProtocol]
+}
+
+/// An `enum` with associated-type cases.
+public struct SwiftAssociatedTypeEnum: SwiftType {
+    public struct Case: SwiftType, SwiftPropertyDefaultValue {
+        public var label: String
+        public var associatedType: SwiftType
+    }
+
+    public var name: String
+    public var comment: String?
+    public var cases: [Case]
+    public var conformance: [SwiftProtocol]
+}
+
+public struct SwiftStruct: SwiftType {
+    public struct Property: SwiftType {
+        /// Mutability levels of a property.
+        /// From the lowest `immutable` to the highest `mutable`.
+        public enum Mutability: Int {
+            case immutable
+            case mutableInternally
+            case mutable
+        }
+
+        public enum CodingKey {
+            /// Static coding key with fixed value.
+            case `static`(value: String)
+            /// Dynamic coding key with value determined at runtime.
+            case `dynamic`
+
+            public var isStatic: Bool {
+                switch self {
+                case .static: return true
+                case .dynamic: return false
+                }
+            }
+        }
+
+        public var name: String
+        public var comment: String?
+        public var type: SwiftType
+        public var isOptional: Bool
+        public var mutability: Mutability
+        public var defaultValue: SwiftPropertyDefaultValue?
+        public var codingKey: CodingKey
+    }
+
+    public var name: String
+    public var comment: String?
+    public var properties: [Property]
+    public var conformance: [SwiftProtocol]
+}
+
+public struct SwiftProtocol: SwiftType {
+    public var name: String
+    public var conformance: [SwiftProtocol]
+
+    public init(name: String, conformance: [SwiftProtocol]) {
+        self.name = name
+        self.conformance = conformance
+    }
+}
+
+/// Reference to any other Swift type.
+public struct SwiftTypeReference: SwiftType {
+    public var referencedTypeName: String
+
+    public init(referencedTypeName: String) {
+        self.referencedTypeName = referencedTypeName
+    }
+}
+
+public let codableProtocol = SwiftProtocol(name: "Codable", conformance: [])
+
+// MARK: - Helpers
+
+public extension SwiftType {
+    /// The name of this type (or `nil` if this type is unnamed).
+    var typeName: String? {
+        let `struct` = self as? SwiftStruct
+        let `enum` = self as? SwiftEnum
+        let associatedTypeEnum = self as? SwiftAssociatedTypeEnum
+        return `struct`?.name ?? `enum`?.name ?? associatedTypeEnum?.name
+    }
+}
+
+// MARK: - Equatable
+
+extension SwiftStruct: Equatable {
+    public static func == (lhs: SwiftStruct, rhs: SwiftStruct) -> Bool {
+        return String(describing: lhs) == String(describing: rhs)
+    }
+}
+
+extension SwiftEnum: Equatable {
+    public static func == (lhs: SwiftEnum, rhs: SwiftEnum) -> Bool {
+        return String(describing: lhs) == String(describing: rhs)
+    }
+}
+
+public func == (lhs: SwiftType, rhs: SwiftType) -> Bool {
+    return String(describing: lhs) == String(describing: rhs)
+}
+
+public func != (lhs: SwiftType, rhs: SwiftType) -> Bool {
+    return !(lhs == rhs)
+}

tools/rum-models-generator/Sources/CodeGeneration/ModelsGenerator.swift

@@ -0,0 +1,74 @@
+/*
+ * Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+ * This product includes software developed at Datadog (https://www.datadoghq.com/).
+ * Copyright 2019-2020 Datadog, Inc.
+ */
+
+import Foundation
+
+/// Generates code from provided JSON schema file.
+public struct ModelsGenerator {
+    public init() {}
+
+    /// Generates code from JSON schema file.
+    /// - Parameter schemaFileURL: the URL of schema file
+    /// - Returns: schema for generated code.
+    public func generateCode(from schemaFileURL: URL) throws -> GeneratedCode {
+        let jsonSchema = try JSONSchemaReader().read(schemaFileURL)
+        let jsonType = try JSONSchemaToJSONTypeTransformer().transform(jsonSchema: jsonSchema)
+        let swiftTypes = try JSONToSwiftTypeTransformer().transform(jsonType: jsonType)
+        return GeneratedCode(swiftTypes: swiftTypes)
+    }
+}
+
+/// Schema describing generated code.
+public struct GeneratedCode {
+    /// An array of Swift schemas describing root constructs in generated code.
+    public let swiftTypes: [SwiftType]
+
+    /// Changes this schema by applying provided decoration.
+    /// It can be used to adjust naming and structure of generated code.
+    public func decorate(using decorator: CodeDecorator) throws -> GeneratedCode {
+        return try decorator.decorate(code: self)
+    }
+
+    /// Renders generated code with provided template.
+    public func print(using template: OutputTemplate, and printer: CodePrinter) throws -> String {
+        let codeText = try printer.print(code: self)
+        return template.render(code: codeText)
+    }
+
+    public init(swiftTypes: [SwiftType]) {
+        self.swiftTypes = swiftTypes
+    }
+}
+
+/// A type decorating generated code.
+/// Decoration can be used to adjust naming and structure in generated code before it is printed.
+public protocol CodeDecorator {
+    func decorate(code: GeneratedCode) throws -> GeneratedCode
+}
+
+/// The template for generated code file.
+public struct OutputTemplate {
+    let header: String
+    let footer: String
+
+    /// Initializer.
+    /// - Parameters:
+    ///   - header: a text block to put before generated code
+    ///   - footer: a text block to put after generated code
+    public init(header: String, footer: String) {
+        self.header = header
+        self.footer = footer
+    }
+
+    func render(code: String) -> String {
+        return [header, code, footer].joined()
+    }
+}
+
+/// Prints generated code.
+public protocol CodePrinter {
+    func print(code: GeneratedCode) throws -> String
+}

tools/rum-models-generator/Sources/RUMModelsGeneratorCore/Output/Printing/ObjcInteropPrinter.swift → tools/rum-models-generator/Sources/CodeGeneration/Print/ObjcInteropPrinter.swift

@@ -35,14 +35,24 @@ import Foundation
 ///         public var integer: NSNumber { foo.integer as NSNumber }
 ///     }
 ///
-internal class ObjcInteropPrinter: BasePrinter {
-    /// The prefix used for types exposed to Obj-c.
-    private let objcTypeNamesPrefix: String
-
-    init(objcTypeNamesPrefix: String) {
+public class ObjcInteropPrinter: BasePrinter, CodePrinter {
+    public init(objcTypeNamesPrefix: String) {
         self.objcTypeNamesPrefix = objcTypeNamesPrefix
     }
 
+    // MARK: - CodePrinter
+
+    public func print(code: GeneratedCode) throws -> String {
+        let objcInteropTransformer = SwiftToObjcInteropTypeTransformer()
+        let objcInteropTypes = try objcInteropTransformer.transform(swiftTypes: code.swiftTypes)
+        return try print(objcInteropTypes: objcInteropTypes)
+    }
+
+    // MARK: - Internal
+
+    /// The prefix used for types exposed to Obj-c.
+    private let objcTypeNamesPrefix: String
+
     func print(objcInteropTypes: [ObjcInteropType]) throws -> String {
         reset()
         try objcInteropTypes.forEach { try print(objcInteropType: $0) }