chore(state) expose State.none

Author: lidio601

lib/src/state_machine.dart

@@ -120,10 +120,6 @@ class State extends Disposable implements Function {
     });
   }
 
-  static const _NONE_STATE_NAME = '__none__';
-
-  State._none(StateMachine machine) : this._(_NONE_STATE_NAME, machine);
-
   State._wildcard() : this._('__wildcard__', null, listenTo: false);
 
   /// Stream of enter events. Enter event occurs every time
@@ -148,24 +144,22 @@ class State extends Disposable implements Function {
   /// You can check that condition with:
   /// 
   /// initialState.onEnter((change) {
-  ///   if (!change.from.isNone) {
+  ///   if (!change.from == State.none) {
   ///     // do something here
   ///   }
   /// })
   /// 
   /// to ignore this false initial event.
   /// 
   /// bool, true if this state is None,
-  /// false otherwise
-  bool get isNone {
-    return name == _NONE_STATE_NAME;
-  }
+  /// false otherwise  
+  static final none = State._('__none__', null, listenTo: false);
 
   @override
   String toString() {
     String name = this.name;
-    if (isNone) {
-      name = 'none - state machine has yet to start';
+    if (this == none) {
+      return 'State: none - state machine has yet to start';
     }
     return 'State: $name (active: ${this()}, machine: ${_machine.name})';
   }
@@ -199,13 +193,13 @@ class StateChange {
   ///   }
   /// })
   bool get isInitial {
-    return this.from.isNone;
+    return this.from == State.none;
   }
 
   @override
   String toString() {
     StringBuffer sb = StringBuffer();
-    String fromName = from.isNone ? '(none)' : from.name;
+    String fromName = isInitial ? '(none)' : from.name;
     sb.writeln('StateChange: ${fromName} --> ${to.name}');
     if (payload != null) {
       sb.writeln('    payload: $payload');
@@ -284,7 +278,7 @@ class StateMachine extends Disposable {
     /// Start the machine in a temporary state.
     /// This allows an initial state transition to occur
     /// when the machine is started via [start].
-    _current = State._none(this);
+    _current = State.none;
 
     manageDisposable(_current);
   }

test/state_machine_test.dart

@@ -32,7 +32,7 @@ void main() {
 
     test('should be in a dummy state until the machine has been started', () {
       expect(machine.current.name, equals('__none__'));
-      expect(machine.current.isNone, isTrue);
+      expect(machine.current == State.none, isTrue);
     });
 
     test('should throw if machine is started more than once', () {

test/state_test.dart

@@ -79,7 +79,7 @@ void main() {
 
     test('.toString() should explain what the __none__ state means', () {
       State noneState = machine.current;
-      expect(noneState.isNone, isTrue);
+      expect(noneState == State.none, isTrue);
       String s = noneState.toString();
       expect(s, contains('machine has yet to start'));
       expect(s, isNot(contains('__none__')));