Merge pull request #3 from jakehawken/jake/LoggingWithExternalHooks

Updated logging to include external hook for extended logging functionality.

Sources/Propagate/PublisherAndSubscriber/PropagateDebug.swift

@@ -19,21 +19,36 @@ public enum DebugLogLevel {
  case none
 }
 
-typealias DebugPair = (logLevel: DebugLogLevel, message: String)
+public typealias LoggingHook = (String) -> Void
+typealias LoggingCombo = (logLevel: DebugLogLevel, message: String, loggingMethod: LoggingMethod?)
 
-internal func safePrint(_ message: String, logType: LogType, debugPair: DebugPair?) {
- guard let pair = debugPair else {
+public enum LoggingMethod {
+
+ case external(LoggingHook)
+
+ @available(*, deprecated, message: "This logging method is intended for debug use only. It is highly recommended that you not check in code using .")
+ case debugPrint
+}
+
+internal func safePrint(_ message: String, logType: LogType, loggingCombo: LoggingCombo?) {
+ guard let combo = loggingCombo else {
  return
  }
- guard logType.canBeShownAt(logLevel: pair.logLevel) else {
+ guard logType.canBeShownAt(logLevel: combo.logLevel) else {
  return
  }
- var output = "<>DEBUG: "
- if pair.message.count > 0 {
- output += "\(pair.message) - "
+ var output = "<>PROPAGATE: "
+ if combo.message.count > 0 {
+ output += "\(combo.message) - "
  }
  output += message
- print(output)
+
+ switch loggingCombo?.loggingMethod {
+ case .debugPrint, nil:
+ print(output)
+ case .external(let hook):
+ hook(output)
+ }
 }
 
 internal enum LogType: Equatable {
@@ -100,6 +115,9 @@ public protocol PropagateDebuggable {
  /// `.debug(logLevel: .operatorsOnly, "Mutations on the name stream.")`
  ///
  /// - returns: The type itself, as a `@discardableResult`, to allow for seamless chaining.
- @available(*, message: "This method is intended for debug use only. It is highly recommended that you not check in code calling this method.")
- @discardableResult func debug(logLevel: DebugLogLevel, _ additionalMessage: String) -> Self
+ @discardableResult func enableLogging(
+ logLevel: DebugLogLevel,
+ _ additionalMessage: String,
+ _ logMethod: LoggingMethod
+ ) -> Self
 }

Sources/Propagate/PublisherAndSubscriber/Publisher.swift

@@ -17,15 +17,15 @@ public class Publisher<T, E: Error> {
  fileprivate var subscribers = WeakBag<Subscriber<T, E>>()
  private(set) public var isCancelled = false
 
- internal var debugPair: (DebugPair)?
+ internal var loggingCombo: (LoggingCombo)?
 
  public init() {
  }
 
  /// Emits a new `StreamState`. If this publisher has previously been
  /// cancelled, this method will be a no-op.
  internal func publishNewState(_ state: State) {
- safePrint("Publishing state \(state). -- \(self)", logType: .pubSub, debugPair: debugPair)
+ safePrint("Publishing state \(state). -- \(self)", logType: .pubSub, loggingCombo: loggingCombo)
  lockQueue.async {
  if self.isCancelled {
  return
@@ -35,7 +35,7 @@ public class Publisher<T, E: Error> {
  }
 
  deinit {
- safePrint("Releasing \(self) from memory.", logType: .lifeCycle, debugPair: debugPair)
+ safePrint("Releasing \(self) from memory.", logType: .lifeCycle, loggingCombo: loggingCombo)
  // The asynchronous cancelAll() can't be called from deinit
  // because it results in a bad access crash.
  handleCancellation()
@@ -58,7 +58,7 @@ public class Publisher<T, E: Error> {
  lockQueue.async { [weak self] in
  self?.subscribers.insert(newSub)
  }
- safePrint("Generating new subscriber: \(newSub) from \(self)", logType: .lifeCycle, debugPair: debugPair)
+ safePrint("Generating new subscriber: \(newSub) from \(self)", logType: .lifeCycle, loggingCombo: loggingCombo)
  return newSub
  }
 
@@ -119,8 +119,12 @@ public extension Publisher {
 
 extension Publisher: PropagateDebuggable {
 
- @discardableResult public func debug(logLevel: DebugLogLevel = .all, _ additionalMessage: String = "") -> Self {
- self.debugPair = (logLevel, additionalMessage)
+ @discardableResult public func enableLogging(
+ logLevel: DebugLogLevel = .all,
+ _ additionalMessage: String = "",
+ _ logMethod: LoggingMethod = .debugPrint
+ ) -> Self {
+ self.loggingCombo = (logLevel, additionalMessage, logMethod)
  return self
  }
 
@@ -131,7 +135,7 @@ extension Publisher: PropagateDebuggable {
 private extension Publisher {
 
  func removeSubscriber(_ subscriber: Subscriber<T,E>) {
- safePrint("Removing \(subscriber) from \(self)", logType: .pubSub, debugPair: debugPair)
+ safePrint("Removing \(subscriber) from \(self)", logType: .pubSub, loggingCombo: loggingCombo)
  self.subscribers.pruneIf { $0 === subscriber }
  subscriber.receive(.cancelled)
  }
@@ -142,9 +146,9 @@ private extension Publisher {
  }
  isCancelled = true
  let removedSubscribers = subscribers.removeAll()
- safePrint("Removing subscribers: \(removedSubscribers)", logType: .pubSub, debugPair: debugPair)
+ safePrint("Removing subscribers: \(removedSubscribers)", logType: .pubSub, loggingCombo: loggingCombo)
  removedSubscribers.forEach {
- safePrint("Sending cancellation signal to \($0)", logType: .pubSub, debugPair: debugPair)
+ safePrint("Sending cancellation signal to \($0)", logType: .pubSub, loggingCombo: loggingCombo)
  $0.receive(.cancelled)
  }
  }
@@ -230,7 +234,7 @@ public class StatefulPublisher<T,E: Error>: Publisher<T, E> {
  safePrint(
  "Generating new subscriber. -- \(self) --> \(newSub)",
  logType: .lifeCycle,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  return newSub
  }

Sources/Propagate/PublisherAndSubscriber/Subscriber+Filter.swift

@@ -22,7 +22,7 @@ public extension Subscriber {
  safePrint(
  "Filtering \(self)",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
 
  return publisher.subscriber()
@@ -97,7 +97,7 @@ public extension Subscriber where T: Equatable {
  safePrint(
  "Removing contiguous duplicates values from \(self).",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  return publisher.subscriber()
  .onCancelled {
@@ -137,7 +137,7 @@ public extension Subscriber where T: Equatable, E: Equatable {
  safePrint(
  "Removing contiguous duplicates values from \(self).",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
 
  return publisher.subscriber()

Sources/Propagate/PublisherAndSubscriber/Subscriber+Map.swift

@@ -26,7 +26,7 @@ public extension Subscriber {
  safePrint(
  "Mapping states from StreamState<\(T.self),\(E.self)> to StreamState<\(NewT.self),\(NewE.self)>",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  return newSubscriber
  .onCancelled {
@@ -41,7 +41,7 @@ public extension Subscriber {
  safePrint(
  "Mapping values from \(T.self) to \(NewT.self)",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  return mapStates { oldState in
  switch oldState {
@@ -77,7 +77,7 @@ public extension Subscriber {
  safePrint(
  "Mapping errors from \(E.self) to \(NewE.self).",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  return mapStates { oldState in
  switch oldState {

Sources/Propagate/PublisherAndSubscriber/Subscriber+Statify.swift

@@ -9,12 +9,16 @@ public extension Subscriber {
  /// Generates a new subscriber that synchronously
  /// emits the last state (if any) when subscribed to.
  func stateful() -> Subscriber<T,E> {
- let publisher = StatefulPublisher<T,E>()
-
- subscribe { state in
- publisher.publishNewState(state)
- }
-
+ boundStatefulPublisher()
+ .subscriber()
+ .onCancelled {
+ _ = self // Capturing self to keep subscriber alive for easier chaining.
+ }
+ }
+
+ func startWith(_ value: T) -> Subscriber<T,E> {
+ let publisher = boundStatefulPublisher()
+ publisher.publish(value)
  return publisher.subscriber()
  .onCancelled {
  _ = self // Capturing self to keep subscriber alive for easier chaining.
@@ -114,3 +118,13 @@ class ScanState<T,E: Error> {
  }
 
 }
+
+private extension Subscriber {
+
+ func boundStatefulPublisher() -> StatefulPublisher<T,E> {
+ let publisher = StatefulPublisher<T,E>()
+ bindTo(publisher)
+ return publisher
+ }
+
+}

Sources/Propagate/PublisherAndSubscriber/Subscriber.swift

@@ -19,7 +19,7 @@ public class Subscriber<T, E: Error> {
  private lazy var callbacks = SinglyLinkedList<ExecutionPair>(firstValue: (callbackQueue, { _ in }))
 
  private(set) public var isCancelled = false
- internal var debugPair: DebugPair?
+ internal var loggingCombo: LoggingCombo?
 
  internal init(canceller: Canceller<T,E>) {
  self.canceller = canceller
@@ -30,7 +30,7 @@ public class Subscriber<T, E: Error> {
  safePrint(
  "Releasing \(self) from memory.",
  logType: .lifeCycle,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  cancel()
  }
@@ -56,8 +56,12 @@ public class Subscriber<T, E: Error> {
 
 extension Subscriber: PropagateDebuggable {
 
- @discardableResult public func debug(logLevel: DebugLogLevel = .all, _ additionalMessage: String = "") -> Self {
- self.debugPair = (logLevel, additionalMessage)
+ @discardableResult public func enableLogging(
+ logLevel: DebugLogLevel = .all,
+ _ additionalMessage: String = "",
+ _ logMethod: LoggingMethod = .debugPrint
+ ) -> Self {
+ self.loggingCombo = (logLevel, additionalMessage, logMethod)
  return self
  }
 
@@ -88,7 +92,7 @@ internal extension Subscriber {
  safePrint(
  "Cancelling \(self)...",
  logType: .lifeCycle,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  canceller.cancel(for: self)
  receive(.cancelled)
@@ -107,7 +111,7 @@ private extension Subscriber {
  safePrint(
  "Received \(state). -- \(self)",
  logType: .pubSub,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  callbacks.forEach { (queue, action) in
  queue.async { action(state) }

Sources/Propagate/PublisherAndSubscriber/ValueOnlySubscriber.swift

@@ -37,7 +37,7 @@ public class ValueOnlySubscriber<T> {
  private var valueCallbacks = [ValueExecutionPair]()
  private var cancelCallbacks = [CancelExecutionPair]()
  private(set) public var isCancelled = false
- private var debugPair: DebugPair?
+ private var loggingCombo: LoggingCombo?
 
  fileprivate init() {}
 
@@ -74,7 +74,7 @@ public class ValueOnlySubscriber<T> {
  safePrint(
  "Inflating ValueOnlySubscriber<T\(T.self)> to \(Subscriber<T,E>.self)",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  return publisher.subscriber().onCancelled {
  _ = self // Capturing self to keep subscriber alive for easier chaining.
@@ -85,7 +85,7 @@ public class ValueOnlySubscriber<T> {
  safePrint(
  "Releasing \(self) from memory.",
  logType: .lifeCycle,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  cancel()
  }
@@ -94,7 +94,7 @@ public class ValueOnlySubscriber<T> {
  safePrint(
  "Received \(value). -- \(self)",
  logType: .lifeCycle,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  valueCallbacks.forEach { (queue, action) in
  queue.async { action(value) }
@@ -111,7 +111,7 @@ public class ValueOnlySubscriber<T> {
  safePrint(
  "Cancelling \(self)...",
  logType: .lifeCycle,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  lockQueue.async { [weak self] in
  self?.isCancelled = true
@@ -125,8 +125,12 @@ public class ValueOnlySubscriber<T> {
 
 extension ValueOnlySubscriber: PropagateDebuggable, CustomStringConvertible {
 
- @discardableResult public func debug(logLevel: DebugLogLevel = .all, _ additionalMessage: String = "") -> Self {
- self.debugPair = (logLevel, additionalMessage)
+ @discardableResult public func enableLogging(
+ logLevel: DebugLogLevel = .all,
+ _ additionalMessage: String = "",
+ _ logMethod: LoggingMethod = .debugPrint
+ ) -> Self {
+ self.loggingCombo = (logLevel, additionalMessage, logMethod)
  return self
  }
 
@@ -193,7 +197,7 @@ public extension ValueOnlySubscriber {
  safePrint(
  "Mapping from \(T.self) to \(NewT.self). -- \(self)",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  return newSub
  }
@@ -204,7 +208,7 @@ public extension ValueOnlySubscriber {
  safePrint(
  "Compact mapping from \(T.self) to \(NewT.self). -- \(self)",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
 
  let newSub = ValueOnlySubscriber<NewT>()
@@ -260,7 +264,7 @@ public extension ValueOnlySubscriber where T: Equatable {
  safePrint(
  "Removing contiguous duplicates from \(self)",
  logType: .operators,
- debugPair: debugPair
+ loggingCombo: loggingCombo
  )
  return new.onCancelled {
  _ = self
@@ -295,7 +299,7 @@ public extension ValueOnlySubscriber {
  safePrint(
  "Combining ValueOnlySubscribers <\(T.self)> and <\(T2.self)>: -- \(memoryAddressStringFor(sub1)) & \(memoryAddressStringFor(sub2))",
  logType: .operators,
- debugPair: sub1.debugPair ?? sub2.debugPair // This will probably be a problem at some point.
+ loggingCombo: sub1.loggingCombo ?? sub2.loggingCombo // This will probably be a problem at some point.
  )
 
  return new.onCancelled {

Tests/PropagateTests/PromiseTests.swift

@@ -4,10 +4,8 @@ import Nimble
 import Quick
 import XCTest
 
-// swiftlint:disable file_length
-// swiftlint:disable:next type_body_length
 class PromiseTests: QuickSpec {
- // swiftlint:disable:next function_body_length
+  
  override func spec() {
 
  var subject: Promise<Int,NSError>!