Add BackupStorage.stored function

Sources/XXMessengerClient/Utils/BackupStorage.swift

@@ -18,6 +18,7 @@ public struct BackupStorage {
 
   public typealias Observer = (Backup?) -> Void
 
+  public var stored: () -> Backup?
   public var store: (Data) throws -> Void
   public var observe: (@escaping Observer) -> Cancellable
   public var remove: () throws -> Void
@@ -43,6 +44,9 @@ extension BackupStorage {
       backup = Backup(date: fileDate, data: fileData)
     }
     return BackupStorage(
+      stored: {
+        backup
+      },
       store: { data in
         let newBackup = Backup(
           date: now(),
@@ -55,7 +59,6 @@ extension BackupStorage {
       observe: { observer in
         let id = UUID()
         observers[id] = observer
-        defer { observers[id]?(backup) }
         return Cancellable {
           observers[id] = nil
         }
@@ -71,6 +74,7 @@ extension BackupStorage {
 
 extension BackupStorage {
   public static let unimplemented = BackupStorage(
+    stored: XCTUnimplemented("\(Self.self).stored"),
     store: XCTUnimplemented("\(Self.self).store"),
     observe: XCTUnimplemented("\(Self.self).observe", placeholder: Cancellable {}),
     remove: XCTUnimplemented("\(Self.self).remove")

Tests/XXMessengerClientTests/Utils/BackupStorageTests.swift

@@ -32,6 +32,10 @@ final class BackupStorageTests: XCTestCase {
       path: path
     )
 
+    XCTAssertNoDifference(
+      storage.stored(),
+      BackupStorage.Backup(date: fileDate, data: fileData)
+    )
     XCTAssertNoDifference(actions, [
       .didLoadFile(path),
       .didGetModifiedTime(path),
@@ -42,43 +46,46 @@ final class BackupStorageTests: XCTestCase {
       actions.append(.didObserve("A", backup))
     }
 
-    XCTAssertNoDifference(actions, [
-      .didObserve("A", .init(date: fileDate, data: fileData))
-    ])
+    XCTAssertNoDifference(actions, [])
+    XCTAssertNoDifference(
+      storage.stored(),
+      BackupStorage.Backup(date: fileDate, data: fileData)
+    )
 
     actions = []
     now = .init(1)
     let data1 = "data-1".data(using: .utf8)!
     try storage.store(data1)
 
+    XCTAssertNoDifference(
+      storage.stored(),
+      BackupStorage.Backup(date: .init(1), data: data1)
+    )
     XCTAssertNoDifference(actions, [
       .didObserve("A", .init(date: .init(1), data: data1)),
       .didSaveFile(path, data1),
     ])
 
     actions = []
-    now = .init(2)
     let observerB = storage.observe { backup in
       actions.append(.didObserve("B", backup))
     }
 
-    XCTAssertNoDifference(actions, [
-      .didObserve("B", .init(date: .init(1), data: data1))
-    ])
+    XCTAssertNoDifference(actions, [])
 
     actions = []
-    now = .init(3)
+    now = .init(2)
     observerA.cancel()
     let data2 = "data-2".data(using: .utf8)!
     try storage.store(data2)
 
     XCTAssertNoDifference(actions, [
-      .didObserve("B", .init(date: .init(3), data: data2)),
+      .didObserve("B", .init(date: .init(2), data: data2)),
       .didSaveFile(path, data2),
     ])
 
     actions = []
-    now = .init(4)
+    now = .init(3)
     try storage.remove()
 
     XCTAssertNoDifference(actions, [
@@ -87,7 +94,7 @@ final class BackupStorageTests: XCTestCase {
     ])
 
     actions = []
-    now = .init(5)
+    now = .init(4)
     observerB.cancel()
     let data3 = "data-3".data(using: .utf8)!
     try storage.store(data3)