Make Firestore use FirebaseDataEncoder and FirebaseDataDecoder (re-implementation of #8858) (#9465)

Author: mortenbekditlevsen

CoreOnly/Tests/FirebasePodTest/Podfile

@@ -37,6 +37,7 @@ target 'FirebasePodTest' do
   pod 'FirebaseCoreDiagnostics', :path => '../../../'
   pod 'FirebaseCoreInternal', :path => '../../../'
   pod 'FirebaseCoreExtension', :path => '../../../'
+  pod 'FirebaseSharedSwift', :path => '../../../'
 
   pod 'FirebaseAnalytics' # Analytics is not open source
 end

FirebaseFirestoreSwift.podspec

@@ -32,8 +32,8 @@ Google Cloud Firestore is a NoSQL document database built for automatic scaling,
   s.requires_arc            = true
   s.source_files = [
     'Firestore/Swift/Source/**/*.swift',
-    'Firestore/third_party/FirestoreEncoder/*.swift',
   ]
 
   s.dependency 'FirebaseFirestore', '~> 9.0'
+  s.dependency 'FirebaseSharedSwift', '~> 9.0'
 end

FirebaseSharedSwift/Sources/third_party/FirebaseDataEncoder/FirebaseDataEncoder.swift

@@ -14,6 +14,18 @@
 
 import Foundation
 
+public protocol StructureCodingPassthroughTypeResolver {
+    static func isPassthroughType<T>(_ t: T) -> Bool
+}
+
+private struct NoPassthroughTypes: StructureCodingPassthroughTypeResolver {
+    static func isPassthroughType<T>(_ t: T) -> Bool {
+        return false
+    }
+}
+
+public protocol StructureCodingUncodedUnkeyed {}
+
 extension DecodingError {
   /// Returns a `.typeMismatch` error describing the expected type.
   ///
@@ -233,6 +245,9 @@ public class FirebaseDataEncoder {
   /// The strategy to use for encoding keys. Defaults to `.useDefaultKeys`.
   open var keyEncodingStrategy: KeyEncodingStrategy = .useDefaultKeys
 
+  /// A type that can resolve which types to 'pass through' - or leave alone while encoding. Defaults to not passing any types through.
+  open var passthroughTypeResolver: StructureCodingPassthroughTypeResolver.Type = NoPassthroughTypes.self
+
   /// Contextual user-provided information for use during encoding.
   open var userInfo: [CodingUserInfoKey : Any] = [:]
 
@@ -242,6 +257,7 @@ public class FirebaseDataEncoder {
     let dataEncodingStrategy: DataEncodingStrategy
     let nonConformingFloatEncodingStrategy: NonConformingFloatEncodingStrategy
     let keyEncodingStrategy: KeyEncodingStrategy
+    let passthroughTypeResolver: StructureCodingPassthroughTypeResolver.Type
     let userInfo: [CodingUserInfoKey : Any]
   }
 
@@ -251,6 +267,7 @@ public class FirebaseDataEncoder {
                     dataEncodingStrategy: dataEncodingStrategy,
                     nonConformingFloatEncodingStrategy: nonConformingFloatEncodingStrategy,
                     keyEncodingStrategy: keyEncodingStrategy,
+                    passthroughTypeResolver: passthroughTypeResolver,
                     userInfo: userInfo)
   }
 
@@ -501,6 +518,7 @@ fileprivate struct _JSONKeyedEncodingContainer<K : CodingKey> : KeyedEncodingCon
   }
 
   public mutating func encode<T : Encodable>(_ value: T, forKey key: Key) throws {
+    if T.self is StructureCodingUncodedUnkeyed.Type { return }
     self.encoder.codingPath.append(key)
     defer { self.encoder.codingPath.removeLast() }
     self.container[_converted(key).stringValue] = try self.encoder.box(value)
@@ -928,6 +946,8 @@ extension __JSONEncoder {
       return (value as! NSDecimalNumber)
     } else if value is _JSONStringDictionaryEncodableMarker {
       return try self.box(value as! [String : Encodable])
+    } else if let object = value as? NSObject, self.options.passthroughTypeResolver.isPassthroughType(value) {
+      return object
     }
 
     // The value should request a container from the __JSONEncoder.
@@ -1166,6 +1186,9 @@ public class FirebaseDataDecoder {
   /// The strategy to use for decoding keys. Defaults to `.useDefaultKeys`.
   open var keyDecodingStrategy: KeyDecodingStrategy = .useDefaultKeys
 
+  /// A type that can resolve which types to 'pass through' - or leave alone while decoding. Defaults to not passing any types through.
+  open var passthroughTypeResolver: StructureCodingPassthroughTypeResolver.Type = NoPassthroughTypes.self
+
   /// Contextual user-provided information for use during decoding.
   open var userInfo: [CodingUserInfoKey : Any] = [:]
 
@@ -1175,6 +1198,7 @@ public class FirebaseDataDecoder {
     let dataDecodingStrategy: DataDecodingStrategy
     let nonConformingFloatDecodingStrategy: NonConformingFloatDecodingStrategy
     let keyDecodingStrategy: KeyDecodingStrategy
+    let passthroughTypeResolver: StructureCodingPassthroughTypeResolver.Type
     let userInfo: [CodingUserInfoKey : Any]
   }
 
@@ -1184,6 +1208,7 @@ public class FirebaseDataDecoder {
                     dataDecodingStrategy: dataDecodingStrategy,
                     nonConformingFloatDecodingStrategy: nonConformingFloatDecodingStrategy,
                     keyDecodingStrategy: keyDecodingStrategy,
+                    passthroughTypeResolver: passthroughTypeResolver,
                     userInfo: userInfo)
   }
 
@@ -1617,6 +1642,11 @@ fileprivate struct _JSONKeyedDecodingContainer<K : CodingKey> : KeyedDecodingCon
   }
 
   public func decode<T : Decodable>(_ type: T.Type, forKey key: Key) throws -> T {
+    if type is StructureCodingUncodedUnkeyed.Type {
+      // Note: not pushing and popping key to codingPath since the key is
+      // not part of the decoded structure.
+      return try T.init(from: self.decoder)
+    }
     guard let entry = self.container[key.stringValue] else {
       throw DecodingError.keyNotFound(key, DecodingError.Context(codingPath: self.decoder.codingPath, debugDescription: "No value associated with key \(_errorDescription(of: key))."))
     }
@@ -2505,12 +2535,12 @@ extension __JSONDecoder {
     return try unbox_(value, as: type) as? T
   }
 
-  fileprivate func unbox_(_ value: Any, as type: Decodable.Type) throws -> Any? {
-    if type == Date.self || type == NSDate.self {
+  fileprivate func unbox_(_ value: Any, as _type: Decodable.Type) throws -> Any? {
+    if _type == Date.self || _type == NSDate.self {
       return try self.unbox(value, as: Date.self)
-    } else if type == Data.self || type == NSData.self {
+    } else if _type == Data.self || _type == NSData.self {
       return try self.unbox(value, as: Data.self)
-    } else if type == URL.self || type == NSURL.self {
+    } else if _type == URL.self || _type == NSURL.self {
       guard let urlString = try self.unbox(value, as: String.self) else {
         return nil
       }
@@ -2520,14 +2550,17 @@ extension __JSONDecoder {
                                                                 debugDescription: "Invalid URL string."))
       }
       return url
-    } else if type == Decimal.self || type == NSDecimalNumber.self {
+    } else if _type == Decimal.self || _type == NSDecimalNumber.self {
       return try self.unbox(value, as: Decimal.self)
-    } else if let stringKeyedDictType = type as? _JSONStringDictionaryDecodableMarker.Type {
+    } else if let stringKeyedDictType = _type as? _JSONStringDictionaryDecodableMarker.Type {
       return try self.unbox(value, as: stringKeyedDictType)
     } else {
       self.storage.push(container: value)
       defer { self.storage.popContainer() }
-      return try type.init(from: self)
+      if self.options.passthroughTypeResolver.isPassthroughType(value) && type(of: value) == _type  {
+        return value
+      }
+      return try _type.init(from: self)
     }
   }
 }

Firestore/Example/Podfile

@@ -116,6 +116,7 @@ if is_platform(:ios)
     target 'Firestore_IntegrationTests_iOS' do
       inherit! :search_paths
 
+      pod 'FirebaseSharedSwift', :path => '../../'
       pod 'FirebaseFirestoreSwift', :path => '../../'
       pod 'GoogleBenchmark', :podspec => 'GoogleBenchmark.podspec'
       pod 'GoogleTest', :podspec => 'GoogleTest.podspec'
@@ -152,6 +153,7 @@ if is_platform(:osx)
     target 'Firestore_IntegrationTests_macOS' do
       inherit! :search_paths
 
+      pod 'FirebaseSharedSwift', :path => '../../'
       pod 'FirebaseFirestoreSwift', :path => '../../'
       pod 'GoogleBenchmark', :podspec => 'GoogleBenchmark.podspec'
       pod 'GoogleTest', :podspec => 'GoogleTest.podspec'
@@ -181,6 +183,7 @@ if is_platform(:tvos)
     target 'Firestore_IntegrationTests_tvOS' do
       inherit! :search_paths
 
+      pod 'FirebaseSharedSwift', :path => '../../'
       pod 'FirebaseFirestoreSwift', :path => '../../'
       pod 'GoogleBenchmark', :podspec => 'GoogleBenchmark.podspec'
       pod 'GoogleTest', :podspec => 'GoogleTest.podspec'

Firestore/Swift/CHANGELOG.md

@@ -1,3 +1,14 @@
+# 10.0.0
+- [changed] `Firestore.Encoder` and `Firestore.Decoder` now wraps the shared `FirebaseDataEncoder` and `FirebaseDataDecoder` types which provides new customization options for encoding and decoding date to and from Firestore - similar to the options present on `JSONEncoder` and `JSONDecoder` from `Foundation`.
+- [added] `Firestore.Encoder.KeyEncodingStrategy`
+- [added] `Firestore.Encoder.DateEncodingStrategy`
+- [added] `Firestore.Encoder.DataEncodingStrategy`
+- [added] `Firestore.Encoder.NonConformingFloatEncodingStrategy`
+- [added] `Firestore.Decoder.KeyDecodingStrategy`
+- [added] `Firestore.Decoder.DateDecodingStrategy`
+- [added] `Firestore.Decoder.DataDecodingStrategy`
+- [added] `Firestore.Decoder.NonConformingFloatDecodingStrategy`
+
 # 9.0.0
 - [added] **Breaking change:** `FirebaseFirestoreSwift` has exited beta and is
   now generally available for use.

Firestore/Swift/Source/Codable/CodablePassThroughTypes.swift

@@ -15,12 +15,15 @@
  */
 
 import Foundation
+import FirebaseSharedSwift
 import FirebaseFirestore
 
-internal func isFirestorePassthroughType<T: Any>(_ value: T) -> Bool {
-  return
-    T.self == GeoPoint.self ||
-    T.self == Timestamp.self ||
-    T.self == FieldValue.self ||
-    T.self == DocumentReference.self
+internal struct FirestorePassthroughTypes: StructureCodingPassthroughTypeResolver {
+  static func isPassthroughType<T>(_ t: T) -> Bool {
+    return
+      t is GeoPoint ||
+      t is Timestamp ||
+      t is FieldValue ||
+      t is DocumentReference
+  }
 }

Firestore/Swift/Source/Codable/CollectionReference+WriteEncodable.swift

@@ -35,6 +35,7 @@ public extension CollectionReference {
                                  encoder: Firestore.Encoder = Firestore.Encoder(),
                                  completion: ((Error?) -> Void)? = nil) throws
     -> DocumentReference {
-    return addDocument(data: try encoder.encode(value), completion: completion)
+    let encoded = try encoder.encode(value)
+    return addDocument(data: encoded, completion: completion)
   }
 }

Firestore/Swift/Source/Codable/DocumentID.swift

@@ -15,6 +15,10 @@
  */
 
 import FirebaseFirestore
+import FirebaseSharedSwift
+
+let documentRefUserInfoKey =
+  CodingUserInfoKey(rawValue: "DocumentRefUserInfoKey")!
 
 /// A type that can initialize itself from a Firestore `DocumentReference`,
 /// which makes it suitable for use with the `@DocumentID` property wrapper.
@@ -76,7 +80,7 @@ internal protocol DocumentIDProtocol {
 /// Firestore.Encoder leads to an error.
 @propertyWrapper
 public struct DocumentID<Value: DocumentIDWrappable & Codable>:
-  DocumentIDProtocol, Codable {
+  DocumentIDProtocol, Codable, StructureCodingUncodedUnkeyed {
   var value: Value?
 
   public init(wrappedValue value: Value?) {
@@ -101,9 +105,12 @@ public struct DocumentID<Value: DocumentIDWrappable & Codable>:
   // MARK: - `Codable` implementation.
 
   public init(from decoder: Decoder) throws {
-    throw FirestoreDecodingError.decodingIsNotSupported(
-      "DocumentID values can only be decoded with Firestore.Decoder"
-    )
+    guard let reference = decoder.userInfo[documentRefUserInfoKey] as? DocumentReference else {
+      throw FirestoreDecodingError.decodingIsNotSupported(
+        "Could not find DocumentReference for user info key: \(documentRefUserInfoKey)"
+      )
+    }
+    try self.init(from: reference)
   }
 
   public func encode(to encoder: Encoder) throws {

Firestore/Swift/Source/Codable/DocumentReference+WriteEncodable.swift

@@ -34,7 +34,8 @@ public extension DocumentReference {
   func setData<T: Encodable>(from value: T,
                              encoder: Firestore.Encoder = Firestore.Encoder(),
                              completion: ((Error?) -> Void)? = nil) throws {
-    setData(try encoder.encode(value), completion: completion)
+    let encoded = try encoder.encode(value)
+    setData(encoded, completion: completion)
   }
 
   /// Encodes an instance of `Encodable` and overwrites the encoded data
@@ -57,7 +58,8 @@ public extension DocumentReference {
                              merge: Bool,
                              encoder: Firestore.Encoder = Firestore.Encoder(),
                              completion: ((Error?) -> Void)? = nil) throws {
-    setData(try encoder.encode(value), merge: merge, completion: completion)
+    let encoded = try encoder.encode(value)
+    setData(encoded, merge: merge, completion: completion)
   }
 
   /// Encodes an instance of `Encodable` and writes the encoded data to the document referred
@@ -84,6 +86,7 @@ public extension DocumentReference {
                              mergeFields: [Any],
                              encoder: Firestore.Encoder = Firestore.Encoder(),
                              completion: ((Error?) -> Void)? = nil) throws {
-    setData(try encoder.encode(value), mergeFields: mergeFields, completion: completion)
+    let encoded = try encoder.encode(value)
+    setData(encoded, mergeFields: mergeFields, completion: completion)
   }
 }