Swift Macros 🚀

Swift Macros have brought in a new wave of possibilities. The aim of this project is to curate a list of community-created Macros and associated learning resources.

A lot of use-cases my Sourcery covered before can now be implemented by Swift Macros.

Learning Resources 📚

Tools

• Swift AST Explorer
  • This is extremely helpful when working with SwiftSyntax, I used this when writing Sourcery parser and you can leverage it to build your own Macros.

Apple:

Dive into Swift Macros with these WWDC sessions:

• Write Swift Macros: An introductory session on Macros, their roles, and workings with a basic example.
• Expand Swift Macros: A deeper exploration into crafting your Macros and testing their functionality.

Other Apple Resources:

• Macros: The Official Step-by-Step Guide to Using Macros for Compile-Time Code Generation in Swift.
• Example Swift Macros: Check out real-world examples from Apple, like @AddCompletionHandler and @AddAsync.

Community Blogs

• Swift Macros by SwiftLee
  • Antoine goes over the introduction of what Macros are and how you can build your own one with an example.
• How to Create Swift Macros in Xcode 15
  • Francesco goes over creating your first macro with testing and some interesting tidbits.
• Exploring Swift Macros
  • Sergey goes over creating a macro for a memberwise initaliser step by step with tests and convenience methods for SwiftSyntax
• Automating RawRepresentable Conformance with Swift Macros
  • Nikita goes over creating a macro for automating the String RawRepresentable conformance.
• Setup to develop Swift Macros
  • A step-by-step tutorial to develop Swift Macros.

Macros 💻

SwiftUI

• EnvironmentValues & EnvironmentValue: Bypass boilerplate code and swiftly support new SwiftUI Environment Keys and Values.
• SFSymbols Macro: A Swift Macro for "type-safe" SF Symbols.
• SF Symbols Generator: A Swift macro generating type-safe SF Symbols.

Models

• Coding Keys: Effortlessly generate CodingKeys for converting snake_case to lowerCamelCase.
• Coding Keys: A Swift Macro for automating CodingKeys creation in Codable structs. Supports custom string mappings for properties.
• Coding Keys: Swift macros generating customizable CodingKeys.
• Builder pattern: Apply the Builder Pattern with ease by generating a Builder helper class, mimicking stored properties of the associated struct.
• Struct Builder Macro: An attached macro that produces a peer struct which implements the builder pattern. This allows the creation of the struct with minimal effort using default values.
• EnhancedMirror: An experimental Mirror alternative that utilizes Swift Macros for static reflection.
• MetaCodable: Generates Codable implementation with following features:
  • Allows custom CodingKey value declaration per variable, instead of requiring you to write for all fields.
  • Allows to create flattened model for nested CodingKey values.
  • Allows to create composition of multiple Codable types.
  • Allows to provide default value in case of decoding failures.
  • Generates member-wise initializer considering the default values.
  • Allows to create custom decoding/encoding strategies.
• Sealed: Parsing easily Sealed Class JSON Model on Server. (ex. kotlin server)

Testing

• Power Assert: Adds assertions that can automatically produce information about the values being evaluated, and present it in an easily digestible form.
• Spyable: A Swift macro that simplifies and automates the process of creating spies for testing. Using the @Spyable annotation on a protocol, the macro generates a spy class that implements the same interface as the protocol and keeps track of interactions with its methods and properties.

Networking

• SwiftRequest: SwiftRequest is a lightweight, type-safe HTTP client for Swift, streamlining the construction and execution of HTTP request build on top of Macros.
• Papyrus: A type-safe, protocol based HTTP client - turn your APIs into Swift protocols. Includes first-class testing support with out of the box mocking.

Enums

• ExtractCaseValue: A Swift macro that extracts associated values from enum cases.

Misc

• MacroKit: A collection of macros including:
  • @PublicInit: Generate public memberwise init
  • @GenerateMock: Create a mock object for testing from a protocol
  • @KeyPathIterable: Like CaseIterable but for available keypaths on a type
  • @StaticMemberIterable: Like CaseIterable but for available static members on a type
  • More to come...
• InitMacro: A Swift Macro implementation that generates initializers for classes and structs with support for default values, wildcards and access control.
• AssociatedObject: A Swift Macro for adding stored properties in Extension to classes defined in external modules, etc.
  (This is implemented by wrapping objc_getAssociatedObject/objc_setAssociatedObject.)
• AssociatedObjectMacro: A Swift Macro for convenient declaration of variables in class extensions.
• AliasMacro: A Swift Macro for defining aliases for types, functions, or variables.
• UtilityType: UtilityType is an innovative library designed to realize TypeScript's UtilityTypes in Swift. See more details: https://www.typescriptlang.org/docs/handbook/utility-types.html
  • @Partial,@Required: Constructs a type with all properties set to optional(@Partial) or require(@Required). This utility will return a type that represents all subsets of a given type.
  • @Pick,@Omit: Constructs a type by picking(@Pick) or removing(@Omit) the set of specific properties keys (only string literal) from attached Type.
  • @Exclude,@Extract: Constructs a type by excluding(@Exclude) or extracting(@Extract) from enum all cases.
  • @Parameters: Constructs a tuple type from the types used in the parameters of a function type.
  • @ReturnType: Constructs a type consisting of the return type of function.
• Reuse Identifier: A Reuse Identifier Macro that is useful in generation of a reuse id for your UICollectionViewCells and UITableViewCells
• SwiftMacros collection: A practical collection of Swift Macros that help code correctly and smartly.
• ModifiedCopyMacro: A Swift macro for making inline copies of a struct by modifying a property.
• DictionaryLiteralShorthandMacro: A Swfit macro for creating dictionary literals with keys as "string representations of corresponding variable names".
• TemporaryVariable: TemporaryVariable provide a macro #info {...}. It capture most function calls and assign them to temporary variables.
• Localizable: Localizable A macro that produces variables and methods, for your localization files. From the enumeration keys.

Take part in this exciting evolution in Swift. Your contributions are most welcome!