fix(observer): [#30] Observe alias entity changes (#31)

pjechris · Mar 9, 2023 · f443053 · f443053
1 parent 2ffba6f
commit f443053
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Showing 3 changed files with 97 additions and 21 deletions.
diff --git a/Sources/CohesionKit/Observer/AliasObserver.swift b/Sources/CohesionKit/Observer/AliasObserver.swift
@@ -33,47 33,57 @@ extension AliasObserver {
  /// Create an observer sending updates every time:
  /// - the ref node change
  /// - the ref node value change
- static func createObserve(
  private static func createObserve(
  for alias: Ref<EntityNode<T>?>,
  queue: DispatchQueue,
  onChange: @escaping OnChangeClosure
  ) -> Subscription {
- var nestedSubscription: Subscription? = nil
  var entityChangesSubscription: Subscription? = alias
  .value
  .map { node in EntityObserver(node: node, queue: .main) }?
  .observe(onChange: onChange)
 
  // subscribe to alias changes
  let subscription = alias.addObserver { node in
  let nodeObserver = node.map { EntityObserver(node: $0, queue: queue) }
- 
 
  queue.async { onChange(nodeObserver?.value) }
- nestedSubscription = nodeObserver?.observe(onChange: onChange)
  // update entity changes subscription
  entityChangesSubscription = nodeObserver?.observe(onChange: onChange)
  }
- 
 
  return Subscription {
  subscription.unsubscribe()
- nestedSubscription?.unsubscribe()
  entityChangesSubscription?.unsubscribe()
  }
  }
- 
 
  /// Create an observer sending updates every time:
  /// - the ref node change
  /// - any of the ref node element change
-   static func createObserve<E>(
  private static func createObserve<E>(
  for alias: Ref<[EntityNode<E>]?>,
  queue: DispatchQueue,
  onChange: @escaping OnChangeClosure
  ) -> Subscription where T == Array<E> {
- var nestedSubscription: Subscription? = nil
  var entitiesChangesSubscriptions: Subscription? = alias
  .value
  .map { nodes in nodes.map { EntityObserver(node: $0, queue: queue) } }?
  .observe(onChange: onChange)
 
  // Subscribe to alias ref changes and to any changes made on the ref collection nodes.
  let subscription = alias.addObserver { nodes in
- let nodeObservers = nodes.map { $0.map { EntityObserver(node: $0, queue: queue) } }
- 
  let nodeObservers = nodes?.map { EntityObserver(node: $0, queue: queue) }
 
  queue.async { onChange(nodeObservers?.value) }
-
- nestedSubscription = nodeObservers?.observe(onChange: onChange)
 
  // update collection changes subscription
  entitiesChangesSubscriptions = nodeObservers?.observe(onChange: onChange)
  }
- 
 
  return Subscription {
  subscription.unsubscribe()
- nestedSubscription?.unsubscribe()
  entitiesChangesSubscriptions?.unsubscribe()
  }
  }
 

diff --git a/Tests/CohesionKitTests/Observer/AliasObserverTests.swift b/Tests/CohesionKitTests/Observer/AliasObserverTests.swift
@@ -2,7 2,7 @@ import XCTest
 @testable import CohesionKit
 
 class AliasObserverTests: XCTestCase {
- func test_observe_refValueChanged_returnRefValue() {
  func test_observe_refValueChanged_onChangeIsCalled() {
  let ref = Ref(value: Optional.some(EntityNode(SingleNodeFixture(id: 1), modifiedAt: 0)))
  let observer = AliasObserver(alias: ref, queue: .main)
  let newValue = SingleNodeFixture(id: 2)
@@ -21,8 21,28 @@ class AliasObserverTests: XCTestCase {
  wait(for: [expectation], timeout: 1)
  XCTAssertEqual(lastReceivedValue, newValue)
  }
-
- func test_observe_refValueChanged_subscribeToValueUpdates() throws {
 
  func test_observe_entityIsUpdated_onChangeIsCalled() throws {
  let node = EntityNode(RootFixture(id: 1, primitive: "", singleNode: SingleNodeFixture(id: 0), listNodes: []), modifiedAt: 0)
  let observer = AliasObserver(alias: Ref(value: node), queue: .main)
  let newValue = RootFixture(id: 1, primitive: "new value", singleNode: SingleNodeFixture(id: 1), listNodes: [])
  var lastObservedValue: RootFixture?
  let expectation = XCTestExpectation()
 
  let subscription = observer.observe {
  lastObservedValue = $0
  expectation.fulfill()
  }
 
  try withExtendedLifetime(subscription) {
  try node.updateEntity(newValue, modifiedAt: 1)
 
  wait(for: [expectation], timeout: 1)
  XCTAssertEqual(lastObservedValue, newValue)
  }
  }
 
  func test_observe_refValueChanged_entityIsUpdated_onChangeIsCalled() throws {
  let ref = Ref(value: Optional.some(EntityNode(SingleNodeFixture(id: 1), modifiedAt: 0)))
  let observer = AliasObserver(alias: ref, queue: .main)
  let newNode = EntityNode(SingleNodeFixture(id: 2), modifiedAt: 0)
@@ -51,13 71,38 @@ class AliasObserverTests: XCTestCase {
  let observer = AliasObserver(alias: ref, queue: .main)
  let newValue = SingleNodeFixture(id: 3)
  var lastReceivedValue: SingleNodeFixture?
- 
 
  _ = observer.observe {
  lastReceivedValue = $0
  }
- 
 
  try node.updateEntity(newValue, modifiedAt: 1)
- 
 
  XCTAssertNil(lastReceivedValue)
  }
 
  func test_observeArray_oneElementChanged_onChangeIsCalled() throws {
  let expectation = XCTestExpectation()
  let nodes = [
  EntityNode(SingleNodeFixture(id: 1), modifiedAt: 0),
  EntityNode(SingleNodeFixture(id: 2), modifiedAt: 0)
  ]
  let ref = Ref(value: Optional.some(nodes))
  let observer = AliasObserver(alias: ref, queue: .main)
  let update = SingleNodeFixture(id: 1, primitive: "Update")
  var lastObservedValue: [SingleNodeFixture]?
 
  let subscription = observer.observe {
  lastObservedValue = $0
  expectation.fulfill()
  }
 
  try withExtendedLifetime(subscription) {
  // try ref.value?[0].updateEntity(SingleNodeFixture(id: 1, primitive: "Update"), modifiedAt: 1)
  try nodes[0].updateEntity(SingleNodeFixture(id: 1, primitive: "Update"), modifiedAt: 1)
 
  wait(for: [expectation], timeout: 1)
  XCTAssertEqual(lastObservedValue?.first, update)
  }
  }
 }
diff --git a/Tests/CohesionKitTests/Observer/EntityObserverTests.swift b/Tests/CohesionKitTests/Observer/EntityObserverTests.swift
@@ -0,0 1,21 @@
 import XCTest
 @testable import CohesionKit
 
 class EntityObserverTests: XCTestCase {
  func test_entityIsUpdated_onChangeIsCalled() throws {
  let node = EntityNode(SingleNodeFixture(id: 0), modifiedAt: 0)
  let observer = EntityObserver(node: node, queue: .main)
  let newEntity = SingleNodeFixture(id: 0, primitive: "new entity version")
  let expectation = XCTestExpectation()
 
  let subscription = observer.observe {
  expectation.fulfill()
  XCTAssertEqual($0, newEntity)
  }
 
  try withExtendedLifetime(subscription) {
  try node.updateEntity(newEntity, modifiedAt: 1)
  wait(for: [expectation], timeout: 0.5)
  }
  }
 }