Restore 9.x Firestore Data Codable behavior (#10598)

Author: paulb777

FirebaseSharedSwift/Sources/third_party/FirebaseDataEncoder/FirebaseDataEncoder.swift

@@ -139,9 +139,12 @@ public class FirebaseDataEncoder {
     /// Defer to `Data` for choosing an encoding.
     case deferredToData
 
-    /// Encoded the `Data` as a Base64-encoded string. This is the default strategy.
+    /// Encode the `Data` as a Base64-encoded string. This is the default strategy.
     case base64
 
+    /// Encode the `Data` as an `NSData` blob.
+    case blob
+
     /// Encode the `Data` as a custom value encoded by the given closure.
     ///
     /// If the closure fails to encode a value into the given encoder, the encoder will encode an empty automatic container in its place.
@@ -874,6 +877,9 @@ extension __JSONEncoder {
     case .base64:
       return NSString(string: data.base64EncodedString())
 
+    case .blob:
+      return data as NSData
+
     case .custom(let closure):
       let depth = self.storage.count
       do {
@@ -1092,6 +1098,9 @@ public class FirebaseDataDecoder {
     /// Decode the `Data` from a Base64-encoded string. This is the default strategy.
     case base64
 
+    /// Decode the `Data` as an `NSData` blob.
+    case blob
+
     /// Decode the `Data` as a custom value decoded by the given closure.
     case custom((_ decoder: Swift.Decoder) throws -> Data)
   }
@@ -2484,6 +2493,12 @@ extension __JSONDecoder {
 
       return data
 
+    case .blob:
+      guard let data = value as? Data else {
+        throw DecodingError._typeMismatch(at: self.codingPath, expectation: type, reality: value)
+      }
+      return data
+
     case .custom(let closure):
       self.storage.push(container: value)
       defer { self.storage.popContainer() }

FirebaseSharedSwift/Tests/third_party/DataEncoderTests.swift

@@ -413,6 +413,37 @@ class TestFirebaseDataEncoder: XCTestCase {
     _testRoundTrip(of: Optional(data), expected: expected)
   }
 
+  func testEncodingDataBlob() {
+    let data = Data([0xDE, 0xAD, 0xBE, 0xEF])
+
+    _testRoundTrip(of: data,
+                   expected: data,
+                   dataEncodingStrategy: .blob,
+                   dataDecodingStrategy: .blob)
+
+    // Optional data should encode the same way.
+    _testRoundTrip(of: Optional(data),
+                   expected: data,
+                   dataEncodingStrategy: .blob,
+                   dataDecodingStrategy: .blob)
+  }
+
+  func testEncodingData2Blob() {
+    let string = "abcdef"
+    let data = string.data(using: .utf8)!
+
+    _testRoundTrip(of: data,
+                   expected: data,
+                   dataEncodingStrategy: .blob,
+                   dataDecodingStrategy: .blob)
+
+    // Optional data should encode the same way.
+    _testRoundTrip(of: Optional(data),
+                   expected: data,
+                   dataEncodingStrategy: .blob,
+                   dataDecodingStrategy: .blob)
+  }
+
   func testEncodingDataCustom() {
     // We'll encode a number instead of data.
     let encode = { (_ data: Data, _ encoder: Encoder) throws -> Void in

Firestore/Swift/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 10.4.0
+- [fixed] Restore 9.x Codable behavior of encoding `Data` types as an `NSData`
+  blob instead of a String.
+
 # 10.0.0
 - [changed] **Breaking Change:** The `DocumentID` constructor from a
   `DocumentReference` is now internal; this does not affect instantiating a

Firestore/Swift/Source/Codable/EncoderDecoder.swift

@@ -23,8 +23,8 @@ public extension Firestore {
     /// The strategy to use in encoding dates. Defaults to `.timestamp`.
     public var dateEncodingStrategy: FirebaseDataEncoder.DateEncodingStrategy = .timestamp
 
-    /// The strategy to use in encoding binary data. Defaults to `.base64`.
-    public var dataEncodingStrategy: FirebaseDataEncoder.DataEncodingStrategy = .base64
+    /// Firestore encodes Data as `NSData` blobs versus the default .base64 strings.
+    public var dataEncodingStrategy: FirebaseDataEncoder.DataEncodingStrategy = .blob
 
     /// The strategy to use in encoding non-conforming numbers. Defaults to `.throw`.
     public var nonConformingFloatEncodingStrategy: FirebaseDataEncoder
@@ -62,8 +62,8 @@ public extension Firestore {
     /// The strategy to use in decoding dates. Defaults to `.timestamp`.
     public var dateDecodingStrategy: FirebaseDataDecoder.DateDecodingStrategy = .timestamp
 
-    /// The strategy to use in decoding binary data. Defaults to `.base64`.
-    public var dataDecodingStrategy: FirebaseDataDecoder.DataDecodingStrategy = .base64
+    /// Firestore decodes Data from `NSData` blobs versus the default .base64 strings.
+    public var dataDecodingStrategy: FirebaseDataDecoder.DataDecodingStrategy = .blob
 
     /// The strategy to use in decoding non-conforming numbers. Defaults to `.throw`.
     public var nonConformingFloatDecodingStrategy: FirebaseDataDecoder