feat: Implement local subject for 'BehaviorSubject'

src/subject/local_subject.rs

@@ -4,6 +4,7 @@ use std::rc::Rc;
 
 type RcPublishers<P> = Rc<RefCell<Vec<Box<P>>>>;
 type _LocalSubject<P> = Subject<RcPublishers<P>, LocalSubscription>;
+type _LocalBehaviorSubject<P, Item> = BehaviorSubject<RcPublishers<P>, LocalSubscription, Item>;
 
 pub type LocalSubject<'a, Item, Err> =
   _LocalSubject<dyn Publisher<Item = Item, Err = Err> + 'a>;
@@ -17,6 +18,18 @@ pub type LocalSubjectErrRef<'a, Item, Err> =
 pub type LocalSubjectRefAll<'a, Item, Err> =
   _LocalSubject<dyn Publisher<Item = &'a Item, Err = &'a Err> + 'a>;
 
+pub type LocalBehaviorSubject<'a, Item, Err> =
+  _LocalBehaviorSubject<dyn Publisher<Item = Item, Err = Err> + 'a, Item>;
+
+pub type LocalBehaviorSubjectRef<'a, Item, Err> =
+  _LocalBehaviorSubject<dyn Publisher<Item = &'a Item, Err = Err> + 'a, Item>;
+
+pub type LocalBehaviorSubjectErrRef<'a, Item, Err> =
+  _LocalBehaviorSubject<dyn Publisher<Item = Item, Err = &'a Err> + 'a, Item>;
+
+pub type LocalBehaviorSubjectRefAll<'a, Item, Err> =
+  _LocalBehaviorSubject<dyn Publisher<Item = &'a Item, Err = &'a Err> + 'a, Item>;
+
 impl<'a, Item, Err> LocalSubject<'a, Item, Err> {
   #[inline]
   pub fn new() -> Self
@@ -53,6 +66,52 @@ impl<'a, Item, Err> LocalObservable<'a> for LocalSubject<'a, Item, Err> {
   }
 }
 
+impl<'a, Item, Err> LocalBehaviorSubject<'a, Item, Err> {
+  #[inline]
+  pub fn new(value: Item) -> Self
+    where
+        Self: Default,
+  {
+    LocalBehaviorSubject {
+      observers: Default::default(),
+      subscription: Default::default(),
+      value,
+    }
+  }
+  #[inline]
+  pub fn subscribed_size(&self) -> usize {
+    self.observers.observers.borrow().len()
+  }
+}
+
+impl<'a, Item, Err> Observable for LocalBehaviorSubject<'a, Item, Err> {
+  type Item = Item;
+  type Err = Err;
+}
+
+impl<'a, Item, Err> LocalObservable<'a> for LocalBehaviorSubject<'a, Item, Err> {
+  type Unsub = LocalSubscription;
+  fn actual_subscribe<O: Observer<Item = Self::Item, Err = Self::Err> + 'a>(
+    self,
+    subscriber: Subscriber<O, LocalSubscription>,
+  ) -> LocalSubscription {
+    let subscription = subscriber.subscription.clone();
+    self.subscription.add(subscription.clone());
+
+    self
+        .observers
+        .observers
+        .borrow_mut()
+        .push(Box::new(subscriber));
+
+    if !subscription.is_closed() {
+      self.observers.observers.borrow_mut().last_mut().unwrap().next(self.value);
+    }
+
+    subscription
+  }
+}
+
 #[cfg(test)]
 mod test {
   use crate::prelude::*;