feat: add YYJSON

CLAUDE.md

@@ -94,6 +94,7 @@ and Flutter projects.
 ./bin/mise run format               # Format all (Swift + Markdown)
 ./bin/mise run format:swift         # Format Swift only
 ./bin/mise run format:md            # Format Markdown only
+./bin/mise run format-check         # Check formatting (CI) - fix with format:swift
 ./bin/mise run lint                 # SwiftLint + actionlint
 
 # Docs & Coverage
@@ -190,22 +191,23 @@ Templates are in `Sources/*/Resources/`. Use Stencil syntax. Update tests after
 
 ## Dependencies
 
-| Package               | Version | Purpose                    |
-| --------------------- | ------- | -------------------------- |
-| swift-argument-parser | 1.5.0+  | CLI framework              |
-| swift-collections     | 1.2.x   | Ordered collections        |
-| Yams                  | 5.3.0+  | YAML parsing               |
-| Stencil               | 0.15.1+ | Template engine            |
-| StencilSwiftKit       | 2.10.1+ | Swift Stencil extensions   |
-| XcodeProj             | 8.27.0+ | Xcode project manipulation |
-| swift-log             | 1.6.0+  | Logging                    |
-| Rainbow               | 4.2.0+  | Terminal colors            |
-| libwebp               | 1.4.1+  | WebP encoding              |
-| libpng                | 1.6.45+ | PNG decoding               |
-| swift-custom-dump     | 1.3.0+  | Test assertions            |
-| Noora                 | 0.54.0+ | Terminal UI design system  |
-| swift-resvg           | 0.45.1  | SVG parsing/rendering      |
-| swift-docc-plugin     | 1.4.5+  | DocC documentation         |
+| Package               | Version | Purpose                     |
+| --------------------- | ------- | --------------------------- |
+| swift-argument-parser | 1.5.0+  | CLI framework               |
+| swift-collections     | 1.2.x   | Ordered collections         |
+| Yams                  | 5.3.0+  | YAML parsing                |
+| Stencil               | 0.15.1+ | Template engine             |
+| StencilSwiftKit       | 2.10.1+ | Swift Stencil extensions    |
+| XcodeProj             | 8.27.0+ | Xcode project manipulation  |
+| swift-log             | 1.6.0+  | Logging                     |
+| Rainbow               | 4.2.0+  | Terminal colors             |
+| libwebp               | 1.4.1+  | WebP encoding               |
+| libpng                | 1.6.45+ | PNG decoding                |
+| swift-custom-dump     | 1.3.0+  | Test assertions             |
+| Noora                 | 0.54.0+ | Terminal UI design system   |
+| swift-resvg           | 0.45.1  | SVG parsing/rendering       |
+| swift-docc-plugin     | 1.4.5+  | DocC documentation          |
+| swift-yyjson          | 0.4.0+  | High-performance JSON codec |
 
 ## Troubleshooting
 

Package.swift

@@ -26,6 +26,7 @@ let package = Package(
         .package(url: "https://github.com/tuist/Noora", from: "0.54.0"),
         .package(url: "https://github.com/swiftlang/swift-docc-plugin", from: "1.4.5"),
         .package(url: "https://github.com/alexey1312/swift-resvg.git", exact: "0.45.1-swift.3"),
+        .package(url: "https://github.com/mattt/swift-yyjson", from: "0.4.0"),
     ],
     targets: [
         // Main target
@@ -53,12 +54,18 @@ let package = Package(
 
         // Shared target
         .target(
-            name: "ExFigCore"
+            name: "ExFigCore",
+            dependencies: [
+                .product(name: "YYJSON", package: "swift-yyjson"),
+            ]
         ),
 
         // Loads data via Figma REST API
         .target(
-            name: "FigmaAPI"
+            name: "FigmaAPI",
+            dependencies: [
+                "ExFigCore",
+            ]
         ),
 
         // Exports resources to Xcode project

Sources/AndroidExport/AndroidThemeAttributesExporter.swift

@@ -38,10 +38,14 @@ public struct ThemeAttributesExportResult: Sendable {
     public let collisions: [ThemeAttributeCollision]
 
     /// Number of attributes generated.
-    public var count: Int { attributeMap.count }
+    public var count: Int {
+        attributeMap.count
+    }
 
     /// Whether any collisions were detected.
-    public var hasCollisions: Bool { !collisions.isEmpty }
+    public var hasCollisions: Bool {
+        !collisions.isEmpty
+    }
 
     public init(
         attrsContent: String,

Sources/ExFig/Batch/BatchExecutor.swift

@@ -237,7 +237,7 @@ actor BatchExecutor {
             var running = 0
             var configIterator = configs.makeIterator()
 
-            // Helper to create rate-limited client and process config
+            /// Helper to create rate-limited client and process config
             func processConfig(_ config: ConfigFile) async -> ConfigResult {
                 let rateLimitedClient = Self.makeRateLimitedClient(
                     for: config,

Sources/ExFig/Batch/BatchResult.swift

@@ -116,7 +116,9 @@ struct GranularCacheStats: Sendable {
     let exported: Int
 
     /// Total nodes processed.
-    var total: Int { skipped + exported }
+    var total: Int {
+        skipped + exported
+    }
 
     /// Merges two stats, returning nil if both are nil.
     static func merge(_ lhs: GranularCacheStats?, _ rhs: GranularCacheStats?) -> GranularCacheStats? {

Sources/ExFig/Batch/FileVersionPreFetcher.swift

@@ -109,7 +109,7 @@ struct FileVersionPreFetcher: Sendable {
             // Pre-fetch failed, proceed without optimization
             // Individual configs will fetch their own metadata
             if configuration.verbose {
-                ui.warning("Pre-fetch failed: \(error.localizedDescription)")
+                ui.warning("Pre-fetch failed: \(error.bestDescription)")
             }
             return nil
         }
@@ -161,7 +161,7 @@ struct FileVersionPreFetcher: Sendable {
             )
         } catch {
             if configuration.verbose {
-                ui.warning("Pre-fetch failed: \(error.localizedDescription)")
+                ui.warning("Pre-fetch failed: \(error.bestDescription)")
             }
             return PreFetchResult(versions: nil, components: nil, nodes: nil)
         }
@@ -325,7 +325,7 @@ struct FileVersionPreFetcher: Sendable {
                         let metadata = try await client.request(endpoint)
                         return (fileId, metadata)
                     } catch {
-                        logger.warning("Pre-fetch metadata failed for file \(fileId): \(error.localizedDescription)")
+                        logger.warning("Pre-fetch metadata failed for file \(fileId): \(error.bestDescription)")
                         return (fileId, nil)
                     }
                 }
@@ -381,13 +381,11 @@ struct FileVersionPreFetcher: Sendable {
         // Capture into let for concurrent access
         let nodeIdsByFileSnapshot = nodeIdsByFile
 
-        let result = try await ui.withSpinner(
+        return try await ui.withSpinner(
             "Pre-fetching nodes for granular cache (\(totalNodes) nodes)..."
         ) {
             try await fetchAllNodes(nodeIdsByFile: nodeIdsByFileSnapshot)
         }
-
-        return result
     }
 
     /// Fetch node documents for all files in parallel.
@@ -433,7 +431,7 @@ struct FileVersionPreFetcher: Sendable {
                         let components = try await client.request(endpoint)
                         return (fileId, components)
                     } catch {
-                        logger.warning("Pre-fetch components failed for file \(fileId): \(error.localizedDescription)")
+                        logger.warning("Pre-fetch components failed for file \(fileId): \(error.bestDescription)")
                         return (fileId, nil)
                     }
                 }

Sources/ExFig/Cache/BatchCheckpoint.swift

@@ -1,3 +1,4 @@
+import ExFigCore
 import Foundation
 
 /// Checkpoint for resuming batch processing of multiple configs.
@@ -97,7 +98,7 @@ public extension BatchCheckpoint {
         }
 
         let data = try Data(contentsOf: fileURL)
-        let decoder = JSONDecoder()
+        var decoder = JSONCodec.makeDecoder()
         decoder.dateDecodingStrategy = .iso8601
         return try decoder.decode(BatchCheckpoint.self, from: data)
     }
@@ -107,9 +108,9 @@ public extension BatchCheckpoint {
     func save(to directory: URL) throws {
         let fileURL = directory.appendingPathComponent(Self.fileName)
 
-        let encoder = JSONEncoder()
+        var encoder = JSONCodec.makeEncoder()
         encoder.dateEncodingStrategy = .iso8601
-        encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
+        encoder.writeOptions = [.prettyPrinted]
 
         let data = try encoder.encode(self)
         try data.write(to: fileURL, options: .atomic)

Sources/ExFig/Cache/CheckpointTracker.swift

@@ -81,8 +81,7 @@ actor CheckpointTracker {
             return nil
         }
 
-        let tracker = CheckpointTracker(existing: existing, directory: directory, assetType: assetType)
-        return tracker
+        return CheckpointTracker(existing: existing, directory: directory, assetType: assetType)
     }
 
     /// Private init for loading existing checkpoint.

Sources/ExFig/Cache/ExportCheckpoint.swift

@@ -1,3 +1,4 @@
+import ExFigCore
 import Foundation
 
 /// Checkpoint for resuming interrupted exports.
@@ -146,7 +147,7 @@ public extension ExportCheckpoint {
         }
 
         let data = try Data(contentsOf: fileURL)
-        let decoder = JSONDecoder()
+        var decoder = JSONCodec.makeDecoder()
         decoder.dateDecodingStrategy = .iso8601
         return try decoder.decode(ExportCheckpoint.self, from: data)
     }
@@ -156,9 +157,9 @@ public extension ExportCheckpoint {
     func save(to directory: URL) throws {
         let fileURL = directory.appendingPathComponent(Self.fileName)
 
-        let encoder = JSONEncoder()
+        var encoder = JSONCodec.makeEncoder()
         encoder.dateEncodingStrategy = .iso8601
-        encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
+        encoder.writeOptions = [.prettyPrinted]
 
         let data = try encoder.encode(self)
         try data.write(to: fileURL, options: .atomic)

Sources/ExFig/Cache/GranularCacheManager.swift

@@ -134,7 +134,7 @@ final class GranularCacheManager: Sendable {
         let batches = nodeIds.chunked(into: batchSize)
 
         // Fetch all batches in parallel with limited concurrency
-        let allNodes = try await withThrowingTaskGroup(
+        return try await withThrowingTaskGroup(
             of: [NodeId: Node].self
         ) { [self] group in
             for batch in batches {
@@ -150,7 +150,5 @@ final class GranularCacheManager: Sendable {
             }
             return results
         }
-
-        return allNodes
     }
 }

Sources/ExFig/Cache/ImageTrackingCache.swift

@@ -1,4 +1,6 @@
+import ExFigCore
 import Foundation
+import Logging
 
 /// Cache model for tracking Figma file versions and node hashes.
 /// Used to skip exports when files haven't changed since last export.
@@ -69,6 +71,8 @@ struct CachedFileInfo: Codable, Sendable {
 // MARK: - Cache Persistence
 
 extension ImageTrackingCache {
+    private static let logger = Logger(label: "com.alexey1312.exfig.image-tracking-cache")
+
     /// Loads cache from a file at the specified path.
     /// Returns an empty cache if file doesn't exist or is invalid.
     /// Migrates from older schema versions automatically.
@@ -79,8 +83,7 @@ extension ImageTrackingCache {
 
         do {
             let data = try Data(contentsOf: path)
-            let decoder = JSONDecoder()
-            let cache = try decoder.decode(ImageTrackingCache.self, from: data)
+            let cache = try JSONCodec.decode(ImageTrackingCache.self, from: data)
 
             // Migration: v1 → v2 (nodeHashes field added, backward compatible)
             if cache.schemaVersion < currentSchemaVersion {
@@ -94,15 +97,22 @@ extension ImageTrackingCache {
 
             return cache
         } catch {
-            // Invalid cache file, return empty cache
+            // Log the error - helps diagnose cache compatibility issues after migrations
+            logger.warning(
+                "Cache file corrupted or incompatible, starting with empty cache",
+                metadata: [
+                    "path": "\(path.path)",
+                    "error": "\(error.localizedDescription)",
+                ]
+            )
             return ImageTrackingCache()
         }
     }
 
     /// Saves cache to a file at the specified path.
     func save(to path: URL) throws {
-        let encoder = JSONEncoder()
-        encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
+        var encoder = JSONCodec.makeEncoder()
+        encoder.writeOptions = [.prettyPrinted]
         let data = try encoder.encode(self)
         try data.write(to: path, options: .atomic)
     }

Sources/ExFig/Cache/NodeHasher.swift

@@ -1,5 +1,7 @@
+import ExFigCore
 import FigmaAPI
 import Foundation
+import Logging
 
 /// Computes stable hashes for Figma node visual properties.
 ///
@@ -12,6 +14,8 @@ import Foundation
 /// - Recursive hashing includes all children
 /// - Float normalization handled at property creation time
 enum NodeHasher {
+    private static let logger = Logger(label: "com.alexey1312.exfig.node-hasher")
+
     /// Computes a stable hash for the given node properties.
     ///
     /// The hash is computed from canonical JSON (sorted keys) of the
@@ -21,15 +25,19 @@ enum NodeHasher {
     /// - Parameter properties: The hashable visual properties of a node.
     /// - Returns: 16-character lowercase hex string (e.g., "a1b2c3d4e5f67890").
     static func computeHash(_ properties: NodeHashableProperties) -> String {
-        let encoder = JSONEncoder()
-        encoder.outputFormatting = [.sortedKeys]
-
         do {
-            let data = try encoder.encode(properties)
+            let data = try JSONCodec.encodeSorted(properties)
             return FNV1aHasher.hashToHex(data)
         } catch {
-            // Encoding should never fail for Encodable types
-            // If it does, return a unique error hash to force re-export
+            // Log the error - this should never happen but needs visibility for debugging
+            logger.warning(
+                "NodeHasher encoding failed, returning zero hash to force re-export",
+                metadata: [
+                    "nodeType": "\(properties.type)",
+                    "error": "\(error.localizedDescription)",
+                ]
+            )
+            // Return error hash to force re-export rather than silently skip
             return "0000000000000000"
         }
     }

Sources/ExFig/Input/FaultToleranceOptions.swift

@@ -193,13 +193,12 @@ struct HeavyFaultToleranceOptions: ParsableArguments {
         }
 
         // Create new checkpoint
-        let tracker = try CheckpointTracker(
+        return try CheckpointTracker(
             configPath: configPath,
             directory: workingDirectory,
             assetType: assetType,
             assetNames: assetNames
         )
-        return tracker
     }
 
     /// Filter files to download based on checkpoint state.