- add asyncMapValues and validate: two new async operators

- deprecate `update`, deprecated non-async `set` without a completion handler (for swift 5.5)
dreymonde · May 1, 2022 · 36290c8 · 36290c8
1 parent 226269e
commit 36290c8
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Showing 2 changed files with 124 additions and 5 deletions.
diff --git a/Sources/Shallows/Async.swift b/Sources/Shallows/Async.swift
@@ -56,4 +56,112 @@ extension WritableStorageProtocol where Key == Void {
         })
     }
 }
+
+public struct ValueValidationError: Error {
+    public init() { }
+}
+
+@available(iOS 13.0.0, *)
+@available(macOS 10.15.0, *)
+@available(watchOS 6.0, *)
+@available(tvOS 13.0.0, *)
+extension ReadOnlyStorageProtocol {
+    public func asyncMapValues<OtherValue>(
+        to type: OtherValue.Type = OtherValue.self,
+        _ transform: @escaping (Value) async throws -> OtherValue
+    ) -> ReadOnlyStorage<Key, OtherValue> {
+        return ReadOnlyStorage<Key, OtherValue>(storageName: storageName, retrieve: { (key, completion) in
+            self.retrieve(forKey: key, completion: { (result) in
+                switch result {
+                case .success(let value):
+                    Task {
+                        do {
+                            let newValue = try await transform(value)
+                            completion(.success(newValue))
+                        } catch {
+                            completion(.failure(error))
+                        }
+                    }
+                case .failure(let error):
+                    completion(.failure(error))
+                }
+            })
+        })
+    }
+
+    public func validate(_ isValid: @escaping (Value) async throws -> Bool) -> ReadOnlyStorage<Key, Value> {
+        return asyncMapValues(to: Value.self) { value in
+            if try await isValid(value) {
+                return value
+            } else {
+                throw ValueValidationError()
+            }
+        }
+    }
+}
+
+@available(iOS 13.0.0, *)
+@available(macOS 10.15.0, *)
+@available(watchOS 6.0, *)
+@available(tvOS 13.0.0, *)
+extension WriteOnlyStorageProtocol {
+    public func asyncMapValues<OtherValue>(
+        to type: OtherValue.Type = OtherValue.self,
+        _ transform: @escaping (OtherValue) async throws -> Value
+    ) -> WriteOnlyStorage<Key, OtherValue> {
+        return WriteOnlyStorage<Key, OtherValue>(storageName: storageName, set: { (value, key, completion) in
+            Task {
+                do {
+                    let newValue = try await transform(value)
+                    self.set(newValue, forKey: key, completion: completion)
+                } catch {
+                    completion(.failure(error))
+                }
+            }
+        })
+    }
+
+    public func validate(_ isValid: @escaping (Value) async throws -> Bool) -> WriteOnlyStorage<Key, Value> {
+        return asyncMapValues(to: Value.self) { value in
+            if try await isValid(value) {
+                return value
+            } else {
+                throw ValueValidationError()
+            }
+        }
+    }
+}
+
+@available(iOS 13.0.0, *)
+@available(macOS 10.15.0, *)
+@available(watchOS 6.0, *)
+@available(tvOS 13.0.0, *)
+extension StorageProtocol {
+    public func asyncMapValues<OtherValue>(to type: OtherValue.Type = OtherValue.self,
+                                      transformIn: @escaping (Value) async throws -> OtherValue,
+                                      transformOut: @escaping (OtherValue) async throws -> Value) -> Storage<Key, OtherValue> {
+        return Storage(read: asReadOnlyStorage().asyncMapValues(transformIn),
+                       write: asWriteOnlyStorage().asyncMapValues(transformOut))
+    }
+
+    public func validate(_ isValid: @escaping (Value) async throws -> Bool) -> Storage<Key, Value> {
+        return asyncMapValues(
+            to: Value.self,
+            transformIn: { value in
+                if try await isValid(value) {
+                    return value
+                } else {
+                    throw ValueValidationError()
+                }
+            },
+            transformOut: { value in
+                if try await isValid(value) {
+                    return value
+                } else {
+                    throw ValueValidationError()
+                }
+            }
+        )
+    }
+}
 #endif
diff --git a/Sources/Shallows/Storage.swift b/Sources/Shallows/Storage.swift
@@ -54,9 +54,14 @@ public struct Storage<Key, Value> : StorageProtocol {
         _retrieve.retrieve(forKey: key, completion: completion)
     }
 
-    public func set(_ value: Value, forKey key: Key, completion: @escaping (ShallowsResult<Void>) -> () = { _ in }) {
+    public func set(_ value: Value, forKey key: Key, completion: @escaping (ShallowsResult<Void>) -> ()) {
         _set.set(value, forKey: key, completion: completion)
     }
+
+    @available(swift, deprecated: 5.5, message: "use async version or provide completion handler explicitly")
+    public func set(_ value: Value, forKey key: Key) {
+        _set.set(value, forKey: key, completion: { _ in })
+    }
 
     public func asReadOnlyStorage() -> ReadOnlyStorage<Key, Value> {
         return _retrieve
@@ -89,7 +94,8 @@ extension StorageProtocol {
         }
         return Storage(self)
     }
-
+
+    @available(swift, deprecated: 5.5, message: "`update` is deprecated because it was creating potentially wrong assumptions regarding the serial nature of this function. `update` cannot guarantee that no concurrent calls to `retrieve` or `set` from other places will be made during the update")
     public func update(forKey key: Key,
                        _ modify: @escaping (inout Value) -> (),
                        completion: @escaping (ShallowsResult<Value>) -> () = { _ in }) {
@@ -173,14 +179,19 @@ extension ReadableStorageProtocol where Key == Void {
 
 extension WritableStorageProtocol where Key == Void {
 
-    public func set(_ value: Value, completion: @escaping (ShallowsResult<Void>) -> () = { _ in }) {
+    public func set(_ value: Value, completion: @escaping (ShallowsResult<Void>) -> ()) {
         set(value, forKey: (), completion: completion)
     }
-
+
+    @available(swift, deprecated: 5.5, message: "use async version or provide completion handler explicitly")
+    public func set(_ value: Value) {
+        set(value, completion: { _ in })
+    }
 }
 
 extension StorageProtocol where Key == Void {
-
+
+    @available(swift, deprecated: 5.5, message: "`update` is deprecated because it was creating potentially wrong assumptions regarding the serial nature of this function. `update` cannot guarantee that no concurrent calls to `retrieve` or `set` from other places will be made during the update")
     public func update(_ modify: @escaping (inout Value) -> (), completion: @escaping (ShallowsResult<Value>) -> () = {_ in }) {
         self.update(forKey: (), modify, completion: completion)
     }