ryanfrancesconi/spfk-raw-codable

Motivation

Swift's synthesized Codable for enums can fail under SwiftData's runtime decoder, which uses Key-Value Coding (KVC) to walk the property graph of composite attributes. When SwiftData encounters an enum stored in a composite struct, it needs the enum to handle its own serialization explicitly rather than relying on compiler-synthesized Codable. Without this, you get NSUnknownKeyException crashes at runtime.

@RawCodable eliminates the boilerplate of writing identical init(from:) / encode(to:) implementations on every RawRepresentable enum in your data model.

Usage

import RawCodable

@RawCodable
public enum BitDepthRule: String, Sendable {
    case lessThanOrEqual
    case any
}

The macro expands to:

extension BitDepthRule: Codable {
    public init(from decoder: any Decoder) throws {
        let container = try decoder.singleValueContainer()
        let rawValue = try container.decode(String.self)
        guard let value = Self(rawValue: rawValue) else {
            throw DecodingError.dataCorruptedError(
                in: container,
                debugDescription: "Unknown \(Self.self) raw value: \(rawValue)"
            )
        }
        self = value
    }

    public func encode(to encoder: any Encoder) throws {
        var container = encoder.singleValueContainer()
        try container.encode(rawValue)
    }
}

Works with both String and Int raw values:

@RawCodable
public enum Priority: Int, Sendable {
    case low = 0
    case medium = 1
    case high = 2
}

Requirements

• Swift 6.2+
• macOS 13+

Installation

Add the package to your Package.swift:

dependencies: [
    .package(url: "https://github.com/ryanfrancesconi/spfk-raw-codable", from: "1.0.0"),
]

Then add RawCodable to your target's dependencies:

.target(
    name: "MyTarget",
    dependencies: [
        .product(name: "RawCodable", package: "spfk-raw-codable"),
    ]
)

License

Copyright Ryan Francesconi. All Rights Reserved.

Package Metadata

Repository: ryanfrancesconi/spfk-raw-codable

Default branch: main

README: README.md