updated reducer debugging

Author: stephencelis

Sources/ComposableArchitecture/Documentation.docc/Extensions/ReducerDebug.md

@@ -0,0 +1,10 @@
+# ``ComposableArchitecture/ReducerProtocol/debug()``
+
+## Topics
+
+### Custom strategies
+
+- ``ReducerProtocol/debug(_:)``
+- ``DebugStrategy``
+- ``CustomDumpStrategy``
+- ``ActionLabelsStrategy``

Sources/ComposableArchitecture/Documentation.docc/Extensions/ReducerProtocol.md

@@ -28,7 +28,7 @@
 
 ### Reducer modifiers
 
-- ``debug(_:state:action:actionFormat:to:)``
+- ``debug()``
 - ``dependency(_:_:)``
 - ``dependencies(_:)``
 - ``signpost(_:log:)``

Sources/ComposableArchitecture/Documentation.docc/Extensions/ReducerProtocolDebug.md

@@ -222,6 +222,60 @@ extension AnyReducer {
   }
 }
 
+/// Determines how the string description of an action should be printed when using the
+/// ``ReducerProtocol/debug(_:state:action:actionFormat:to:)`` higher-order reducer.
+@available(
+  iOS,
+  deprecated: 9999.0,
+  message: """
+    This API that used this type has been soft-deprecated in favor of 'ReducerProtocol.debug'. Read the migration guide for more information: https://pointfreeco.github.io/swift-composable-architecture/protocol/documentation/composablearchitecture/reducerprotocols
+    """
+)
+@available(
+  macOS,
+  deprecated: 9999.0,
+  message: """
+    This API that used this type has been soft-deprecated in favor of 'ReducerProtocol.debug'. Read the migration guide for more information: https://pointfreeco.github.io/swift-composable-architecture/protocol/documentation/composablearchitecture/reducerprotocols
+    """
+)
+@available(
+  tvOS,
+  deprecated: 9999.0,
+  message: """
+    This API that used this type has been soft-deprecated in favor of 'ReducerProtocol.debug'. Read the migration guide for more information: https://pointfreeco.github.io/swift-composable-architecture/protocol/documentation/composablearchitecture/reducerprotocols
+    """
+)
+@available(
+  watchOS,
+  deprecated: 9999.0,
+  message: """
+    This API that used this type has been soft-deprecated in favor of 'ReducerProtocol.debug'. Read the migration guide for more information: https://pointfreeco.github.io/swift-composable-architecture/protocol/documentation/composablearchitecture/reducerprotocols
+    """
+)
+public enum ActionFormat: Sendable {
+  /// Prints the action in a single line by only specifying the labels of the associated values:
+  ///
+  /// ```swift
+  /// Action.screenA(.row(index:, action: .textChanged(query:)))
+  /// ```
+  case labelsOnly
+
+  /// Prints the action in a multiline, pretty-printed format, including all the labels of
+  /// any associated values, as well as the data held in the associated values:
+  ///
+  /// ```swift
+  /// Action.screenA(
+  ///   ScreenA.row(
+  ///     index: 1,
+  ///     action: RowAction.textChanged(
+  ///       query: "Hi"
+  ///     )
+  ///   )
+  /// )
+  /// ```
+  case prettyPrint
+}
+
 /// The API that used this type has been soft-deprecated in favor of
 /// ``ReducerProtocol/debug(_:state:action:actionFormat:to:)`` Read <doc:ReducerProtocols> for more
 /// information.

Sources/ComposableArchitecture/Reducer/AnyReducer/AnyReducerDebug.swift

@@ -3,116 +3,67 @@ extension ReducerProtocol {
   ///
   /// > Note: Printing is only done in `DEBUG` configurations.
   ///
-  /// - Parameters:
-  ///   - prefix: A string that will prefix all debug messages.
-  ///   - actionFormat: The format used to print actions.
-  ///   - logger: A function that is used to print debug messages.
   /// - Returns: A reducer that prints debug messages for all received actions.
   @inlinable
-  public func debug(
-    _ prefix: String = "",
-    actionFormat: ActionFormat = .prettyPrint,
-    to logger: @escaping @Sendable (String) async -> Void = { print($0) }
-  ) -> _DebugReducer<Self, State, Action> {
-    self.debug(
-      prefix,
-      state: { $0 },
-      action: { $0 },
-      actionFormat: actionFormat,
-      to: logger
-    )
+  public func debug() -> _DebugReducer<Self, CustomDumpStrategy> {
+    .init(base: self, strategy: .customDump)
   }
 
-  /// Enhances a reducer with debug logging of received actions and state mutations.
+  /// Enhances a reducer with debug logging of received actions and state mutations for the given
+  /// ``DebugStrategy``.
   ///
   /// > Note: Printing is only done in `DEBUG` configurations.
   ///
-  /// - Parameters:
-  ///   - prefix: A string with which to prefix all debug messages.
-  ///   - toChildState: A function that filters state to be printed.
-  ///   - toChildAction: A case path that filters actions to be printed.
-  ///   - actionFormat: The format used to print actions.
-  ///   - logger: A function that is used to print debug messages.
-  /// - Returns: A reducer that prints debug messages for all received, filtered actions.
+  /// - Parameter strategy: A strategy for printing debug messages.
+  /// - Returns: A reducer that prints debug messages for all received actions.
   @inlinable
-  public func debug<ChildState, ChildAction>(
-    _ prefix: String = "",
-    state toChildState: @escaping (State) -> ChildState,
-    action toChildAction: @escaping (Action) -> ChildAction?,
-    actionFormat: ActionFormat = .prettyPrint,
-    to logger: @escaping @Sendable (String) async -> Void = { print($0) }
-  ) -> _DebugReducer<Self, ChildState, ChildAction> {
-    .init(
-      base: self,
-      prefix: prefix,
-      state: toChildState,
-      action: toChildAction,
-      actionFormat: actionFormat,
-      logger: logger
-    )
+  public func debug<Strategy: DebugStrategy>(
+    _ strategy: Strategy
+  ) -> _DebugReducer<Self, Strategy> {
+    .init(base: self, strategy: strategy)
   }
 }
 
-/// Determines how the string description of an action should be printed when using the
-/// ``ReducerProtocol/debug(_:state:action:actionFormat:to:)`` higher-order reducer.
-public enum ActionFormat: Sendable {
-  /// Prints the action in a single line by only specifying the labels of the associated values:
-  ///
-  /// ```swift
-  /// Action.screenA(.row(index:, action: .textChanged(query:)))
-  /// ```
-  case labelsOnly
-
-  /// Prints the action in a multiline, pretty-printed format, including all the labels of
-  /// any associated values, as well as the data held in the associated values:
-  ///
-  /// ```swift
-  /// Action.screenA(
-  ///   ScreenA.row(
-  ///     index: 1,
-  ///     action: RowAction.textChanged(
-  ///       query: "Hi"
-  ///     )
-  ///   )
-  /// )
-  /// ```
-  case prettyPrint
+public protocol DebugStrategy {
+  func debug<Action, State>(receivedAction: Action, oldState: State, newState: State)
 }
 
-public struct _DebugReducer<Base: ReducerProtocol, DebugState, DebugAction>: ReducerProtocol {
-  @usableFromInline
-  let base: Base
+extension DebugStrategy where Self == CustomDumpStrategy {
+  public static var customDump: Self { Self() }
+}
 
-  @usableFromInline
-  let prefix: String
+public struct CustomDumpStrategy: DebugStrategy {
+  public func debug<Action, State>(receivedAction: Action, oldState: State, newState: State) {
+    var target = ""
+    target.write("received action:\n")
+    CustomDump.customDump(receivedAction, to: &target, indent: 2)
+    target.write("\n")
+    target.write(diff(oldState, newState).map { "\($0)\n" } ?? "  (No state changes)\n")
+    print(target)
+  }
+}
 
-  @usableFromInline
-  let toDebugState: (State) -> DebugState
+extension DebugStrategy where Self == ActionLabelsStrategy {
+  public static var actionLabels: Self { Self() }
+}
 
-  @usableFromInline
-  let toDebugAction: (Action) -> DebugAction?
+public struct ActionLabelsStrategy: DebugStrategy {
+  public func debug<Action, State>(receivedAction: Action, oldState: State, newState: State) {
+    print("received action: \(debugCaseOutput(receivedAction))")
+  }
+}
 
+public struct _DebugReducer<Base: ReducerProtocol, Strategy: DebugStrategy>: ReducerProtocol {
   @usableFromInline
-  let actionFormat: ActionFormat
+  let base: Base
 
   @usableFromInline
-  let logger: @Sendable (String) async -> Void
+  let strategy: Strategy
 
   @inlinable
-  init(
-    base: Base,
-    prefix: String,
-    state toDebugState: @escaping (State) -> DebugState,
-    action toDebugAction: @escaping (Action) -> DebugAction?,
-    actionFormat: ActionFormat,
-    logger: @escaping @Sendable (String) async -> Void
-  ) {
+  init(base: Base, strategy: Strategy) {
     self.base = base
-    self.prefix = prefix
-    self.toDebugState = toDebugState
-    self.toDebugAction = toDebugAction
-    self.actionFormat = actionFormat
-    self.logger = logger
+    self.strategy = strategy
   }
 
   @usableFromInline
@@ -124,29 +75,11 @@ public struct _DebugReducer<Base: ReducerProtocol, DebugState, DebugAction>: Red
   ) -> Effect<Base.Action, Never> {
     #if DEBUG
       if self.context != .test {
-        let previousState = self.toDebugState(state)
+        let oldState = state
         let effects = self.base.reduce(into: &state, action: action)
-        guard let debugAction = self.toDebugAction(action) else { return effects }
-        let nextState = self.toDebugState(state)
         return effects.merge(
-          with: .fireAndForget { [actionFormat] in
-            var actionOutput = ""
-            if actionFormat == .prettyPrint {
-              customDump(debugAction, to: &actionOutput, indent: 2)
-            } else {
-              actionOutput.write(debugCaseOutput(debugAction).indent(by: 2))
-            }
-            let stateOutput =
-            DebugState.self == Void.self
-            ? ""
-            : diff(previousState, nextState).map { "\($0)\n" } ?? "  (No state changes)\n"
-            await self.logger(
-              """
-              \(self.prefix.isEmpty ? "" : "\(self.prefix): ")received action:
-              \(actionOutput)
-              \(stateOutput)
-              """
-            )
+          with: .fireAndForget { [newState = state] in
+            self.strategy.debug(receivedAction: action, oldState: oldState, newState: newState)
           }
         )
       }