Merge pull request #172 from LoveCommunity/refactor/make-states-auto-cache

refactor - apply cache behavior to `States`

Author: beeth0ven

lib/src/dart_observable/states/observable_as_states_x.dart

@@ -6,5 +6,8 @@ import 'states.dart';
 extension ObservableAsStatesX<T> on Observable<T> {
 
   /// Cast an Observable to States.
-  States<T> asStates() => States<T>.from(this);
+  States<T> asStates() {
+    final observable = multicastReplay(1);
+    return States<T>.from(observable);
+  }
 }

lib/src/dart_observable/states/states.dart

@@ -49,9 +49,10 @@ class States<T> {
   /// });
   /// ```
   /// 
-  States(
+  factory States(
     Observe<T> observe
-  ): this.from(Observable(observe));
+  ) => Observable(observe)
+    .asStates();
 
   /// Combine multiple `States` into one `States`.
   /// 
@@ -106,7 +107,7 @@ class States<T> {
     combiner: combiner,
   ).asStates();
 
-  /// Cast an `Observable` to `States`.
+  /// Create `States` from raw `Observable`.
   const States.from(this.observable);
 
   /// The underlining raw `observable` that is promised to 
@@ -188,18 +189,6 @@ extension StatesX<T> on States<T> {
       .asStates();
   }
 
-  /// Cache the computed state.
-  /// 
-  /// Instead of computing state very time when observed,
-  /// `Cache` will cache latest state and replay it to new observer. 
-  /// This cache will keep in sync with source `States`.
-  /// 
-  States<T> cache() {
-    return observable
-      .multicastReplay(1)
-      .asStates();
-  }
-
   /// Suppress the first n items emitted by States.
   /// 
   /// You can ignore the first n items emitted by States 
@@ -242,4 +231,4 @@ extension StatesX<T> on States<T> {
       states: this
     );
   }
-}
+}

test/dart_observable/dart_observable_test.dart

@@ -1,6 +1,6 @@
 
+import 'states/observable_as_states_test.dart' as observable_as_states_test;
 import 'states/states_activated_test.dart' as states_activated_test;
-import 'states/states_cache_test.dart' as states_cache_test;
 import 'states/states_cast_test.dart' as states_cast_test;
 import 'states/states_combine_test.dart' as states_combine_test;
 import 'states/states_default_constructor_test.dart' as states_default_constructor_test;
@@ -29,8 +29,8 @@ import 'models/async_test.dart' as async_test;
 
 
 void main() {
+  observable_as_states_test.main();
   states_activated_test.main();
-  states_cache_test.main();
   states_cast_test.main();
   states_combine_test.main();
   states_default_constructor_test.main();

test/dart_observable/states/states_cache_test.dart renamed to test/dart_observable/states/observable_as_states_test.dart

@@ -1,49 +1,50 @@
 
+
 import 'package:test/test.dart';
 import 'package:dart_scope/dart_scope.dart';
 
 import '../shared/states_tester.dart';
 
 void main() {
 
-  test('`states.cache` connect when observers increase to one', () {
+  test('`observable.asStates` connect when observers increase to one', () {
 
     int invokes = 0;
 
-    final states = States<String>((setState) {
-      setState('a');
+    final observable = Observable<String>((onData) {
+      onData('a');
       invokes += 1;
       return Disposable.empty;
     });
 
-    final cache = states.cache();
+    final states = observable.asStates();
 
     expect(invokes, 0);
-    final observation1 = cache.observe((_) {});
+    final observation1 = states.observe((_) {});
     expect(invokes, 1);
-    final observation2 = cache.observe((_) {});
+    final observation2 = states.observe((_) {});
     expect(invokes, 1);
 
     observation1.dispose();
     observation2.dispose();
 
   });
 
-  test('`states.cache` disconnect when observers decrease to zero', () {
+  test('`observable.asStates` disconnect when observers decrease to zero', () {
 
     int invokes = 0;
 
-    final states = States<String>((setState) {
-      setState('a');
+    final observable = Observable<String>((onData) {
+      onData('a');
       return Disposable(() {
         invokes += 1;
       });
     });
 
-    final cache = states.cache();
+    final states = observable.asStates();
 
-    final observation1 = cache.observe((_) {});
-    final observation2 = cache.observe((_) {});
+    final observation1 = states.observe((_) {});
+    final observation2 = states.observe((_) {});
 
     expect(invokes, 0);
     observation1.dispose();
@@ -53,28 +54,28 @@ void main() {
 
   });
 
-  test('`states.cache` forward data to observers', () async {
+  test('`observable.asStates` forward data to observers', () async {
 
-    final states = States<String>((setState) {
-      setState('a');
-      Future(() => setState('b'));
+    final observable = Observable<String>((onData) {
+      onData('a');
+      Future(() => onData('b'));
       return Disposable.empty;
     });
 
-    final cache = states.cache();
+    final states = observable.asStates();
 
     final tester1 = StatesTester(
-      cache,
-    ); 
+      states,
+    );
 
     final tester2 = StatesTester(
-      cache,
-    ); 
+      states,
+    );
 
 
     tester1.startObserve();
     tester2.startObserve();
-    
+
     expect(tester1.recorded, [
       'a',
     ]);
@@ -96,22 +97,22 @@ void main() {
 
   });
 
-  test('`states.cache` replay data to observers', () {
+  test('`observable.asStates` replay data to observers', () {
 
-    final states = States<String>((setState) {
-      setState('a');
-      setState('b');
-      setState('c');
+    final observable = Observable<String>((onData) {
+      onData('a');
+      onData('b');
+      onData('c');
       return Disposable.empty;
     });
 
-    final cache = states.cache();
+    final states = observable.asStates();
 
     final tester = StatesTester(
-      cache,
+      states,
     );
 
-    final observation  = cache.observe((_) {});
+    final observation  = states.observe((_) {});
 
     expect(tester.recorded, <String>[]);
     tester.startObserve();
@@ -125,3 +126,4 @@ void main() {
   });
 
 }
+

test/dart_observable/states/states_from_test.dart

@@ -15,18 +15,6 @@ void main() {
     expect(states.observable, observable);
 
   });
-
-  test("`observable.asStates`'s observable is identical to origin observable", () {
-
-    final observable = Observable<String>((onData) {
-      return Disposable.empty;
-    });
-
-    final states = observable.asStates();
-
-    expect(states.observable, observable);
-
-  });
 
   test("`states.observe` cause observable observe", () {