Add Combine support to Firestore

Firestore/Swift/Source/Combine/CollectionReference+Combine.swift

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2019 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if canImport(Combine) && swift(>=5.0)
+
+  import Combine
+  import FirebaseFirestore
+
+  @available(swift 5.0)
+  @available(macOS 10.15, iOS 13, watchOS 6, tvOS 13, *)
+  extension CollectionReference {
+    public func addDocumentPublisher(data: [String: Any])
+      -> AnyPublisher<DocumentReference, Error> {
+      var reference: DocumentReference!
+      return Future { reference = self.addDocument(data: data, completion: $0) }
+        .map { reference }
+        .eraseToAnyPublisher()
+    }
+
+    public func addDocumentPublisher<T: Encodable>(from value: T,
+                                                   encoder: Firestore.Encoder = Firestore
+                                                     .Encoder()) -> AnyPublisher<
+      DocumentReference,
+      Error
+    > {
+      var reference: DocumentReference!
+      return Future { promise in
+        do {
+          try reference = self.addDocument(from: value, encoder: encoder, completion: promise)
+        } catch {
+          promise(.failure(error))
+        }
+      }
+      .map { reference }
+      .eraseToAnyPublisher()
+    }
+  }
+
+#endif

Firestore/Swift/Source/Combine/DocumentReference+Combine.swift

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+/*
+ * Copyright 2019 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if canImport(Combine) && swift(>=5.0)
+
+  import Combine
+  import FirebaseFirestore
+
+  @available(swift 5.0)
+  @available(macOS 10.15, iOS 13, watchOS 6, tvOS 13, *)
+  extension DocumentReference {
+    func setDataPublisher(_ documentData: [String: Any]) -> Future<Void, Error> {
+      Future { self.setData(documentData, completion: $0) }
+    }
+
+    func setDataPublisher(_ documentData: [String: Any], merge: Bool) -> Future<Void, Error> {
+      Future { self.setData(documentData, merge: merge, completion: $0) }
+    }
+
+    func setDataPublisher(_ documentData: [String: Any],
+                          mergeFields: [Any]) -> Future<Void, Error> {
+      Future { self.setData(documentData, mergeFields: mergeFields, completion: $0) }
+    }
+
+    func setDataPublisher<T: Encodable>(from value: T,
+                                        encoder: Firestore.Encoder = Firestore.Encoder()) -> Future<
+      Void,
+      Error
+    > {
+      Future { promise in
+        do {
+          try self.setData(from: value, completion: promise)
+        } catch {
+          promise(.failure(error))
+        }
+      }
+    }
+
+    func setDataPublisher<T: Encodable>(from value: T, merge: Bool,
+                                        encoder: Firestore.Encoder = Firestore.Encoder()) -> Future<
+      Void,
+      Error
+    > {
+      Future { promise in
+        do {
+          try self.setData(from: value, merge: merge, completion: promise)
+        } catch {
+          promise(.failure(error))
+        }
+      }
+    }
+
+    func setDataPublisher<T: Encodable>(from value: T, mergeFields: [Any],
+                                        encoder: Firestore.Encoder = Firestore.Encoder()) -> Future<
+      Void,
+      Error
+    > {
+      Future { promise in
+        do {
+          try self.setData(from: value, mergeFields: mergeFields, completion: promise)
+        } catch {
+          promise(.failure(error))
+        }
+      }
+    }
+
+    func updateDataPublisher(_ documentData: [String: Any]) -> Future<Void, Error> {
+      Future { self.updateData(documentData, completion: $0) }
+    }
+
+    func deletePublisher() -> Future<Void, Error> {
+      Future(delete)
+    }
+
+    func getDocumentPublisher(source: FirestoreSource = .default)
+      -> Future<DocumentSnapshot, Error> {
+      Future { self.getDocument(source: source, completion: $0) }
+    }
+
+    func addSnapshotListenerPublisher(includeMetadataChanges: Bool = false)
+      -> AnyPublisher<DocumentSnapshot, Error> {
+      let subject = PassthroughSubject<DocumentSnapshot, Error>()
+      let listenerHandle = addSnapshotListener { result in
+        switch result {
+        case let .success(output):
+          subject.send(output)
+        case let .failure(error):
+          subject.send(completion: .failure(error))
+        }
+      }
+      return subject
+        .handleEvents(receiveCancel: listenerHandle.remove)
+        .eraseToAnyPublisher()
+    }
+  }
+
+#endif

Firestore/Swift/Source/Combine/Query+Combine.swift

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+/*
+ * Copyright 2019 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if canImport(Combine) && swift(>=5.0)
+
+  import Combine
+  import FirebaseFirestore
+
+  @available(swift 5.0)
+  @available(macOS 10.15, iOS 13, watchOS 6, tvOS 13, *)
+  extension Query {
+    func getDocumentsPublisher(source: FirestoreSource = .default) -> Future<QuerySnapshot, Error> {
+      Future { self.getDocuments(source: source, completion: $0) }
+    }
+
+    func addSnapshotListenerPublisher(includeMetadataChanges: Bool = false)
+      -> AnyPublisher<QuerySnapshot, Error> {
+      let subject = PassthroughSubject<QuerySnapshot, Error>()
+      let listenerHandle = addSnapshotListener { result in
+        switch result {
+        case let .success(output):
+          subject.send(output)
+        case let .failure(error):
+          subject.send(completion: .failure(error))
+        }
+      }
+      return subject
+        .handleEvents(receiveCancel: listenerHandle.remove)
+        .eraseToAnyPublisher()
+    }
+  }
+
+#endif

Firestore/Swift/Source/Combine/Transaction+Combine.swift

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2019 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if canImport(Combine) && swift(>=5.0)
+
+  import Combine
+  import FirebaseFirestore
+
+  @available(swift 5.0)
+  @available(macOS 10.15, iOS 13, watchOS 6, tvOS 13, *)
+  extension Firestore {
+    func runTransactionPublisher<T>(_ updateBlock: @escaping (Transaction) throws -> T)
+      -> Future<T, Error> {
+      Future { self.runTransaction(updateBlock, completion: $0) }
+    }
+  }
+
+#endif

Firestore/Swift/Source/Combine/WriteBatch+Combine.swift

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+/*
+ * Copyright 2019 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if canImport(Combine) && swift(>=5.0)
+
+  import Combine
+  import FirebaseFirestore
+
+  @available(swift 5.0)
+  @available(macOS 10.15, iOS 13, watchOS 6, tvOS 13, *)
+  extension WriteBatch {
+    /// Commits all of the writes in this write batch as a single atomic unit.
+    ///
+    /// - Returns: A publisher that emits a `Void` value once all of the writes in the batch
+    ///   have been successfully written to the backend as an atomic unit. This publisher will only
+    ///   emits when the client is online and the commit has completed against the server.
+    ///   The changes will be visible immediately.
+    func commitPublisher() -> Future<Void, Error> {
+      Future { self.commit(completion: $0) }
+    }
+  }
+
+#endif

Firestore/Swift/Source/Result/CollectionReference+Result.swift

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2019 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import FirebaseFirestore
+
+#if swift(>=5.0)
+
+  extension CollectionReference {
+    /// Adds a new document to this collection with the specified data, assigning it a document ID automatically.
+    ///
+    /// - Parameters:
+    ///   - data: The `Dictionary` containing the data for the new document.
+    ///   - completion: The closure to execute on successfully writing to the server or on receipt of an error.
+    ///   It will not be called while the client is offline, though local changes will be visible immediately.
+    ///   - result: The result of request. On success it is empty, otherwise it contains an `Error`.
+    /// - Returns: A `DocumentReference` pointing to the newly created document.
+    func addDocument(data: [String: Any],
+                     completion: @escaping (_ result: Result<Void, Error>) -> Void)
+      -> DocumentReference {
+      addDocument(data: data, completion: mapResultClosure(completion))
+    }
+
+    /// Adds a new document to this collection encoding an instance of `Encodable`,  assigning it a document ID automatically.
+    ///
+    /// See Firestore.Encoder for more details about the encoding process.
+    ///
+    /// - Parameters:
+    ///   - value: The instance of Encodable to be encoded to a document.
+    ///   - encoder: The encoder instance to use to run the encoding.
+    ///   - completion: The closure to execute on successfully writing to the server or on receipt of an error.
+    ///   It will not be called while the client is offline, though local changes will be visible immediately.
+    ///   - result: The result of request. On success it is empty, otherwise it contains an `Error`.
+    /// - Throws: `Firestore.Encoder` encoding errors:
+    ///   - *put list of possible errors*
+    /// - Returns: A `DocumentReference` pointing to the newly created document.
+    func addDocument<T: Encodable>(from value: T,
+                                   encoder: Firestore.Encoder = Firestore.Encoder(),
+                                   completion: @escaping (_ result: Result<Void, Error>)
+                                     -> Void) throws -> DocumentReference {
+      try addDocument(from: value, encoder: encoder, completion: mapResultClosure(completion))
+    }
+  }
+
+  /// Returns a closure mapped from the a given closure with a `Result` parameter.
+  ///
+  /// - Parameters:
+  ///   - completion: The closure to map.
+  ///   - result: The parameter of the closure to map.
+  /// - Returns: A closure mapped from the given closure.
+  private func mapResultClosure<E>(_ completion: @escaping (_ result: Result<Void, E>) -> Void)
+    -> ((E?) -> Void) {
+    { error in
+      if let error = error {
+        completion(.failure(error))
+      } else {
+        completion(.success(()))
+      }
+    }
+  }
+
+#endif