update

node_modules/rxjs/src/internal/Subject.ts

@@ -0,0 +1,185 @@
+import { Operator } from './Operator';
+import { Observable } from './Observable';
+import { Subscriber } from './Subscriber';
+import { Subscription, EMPTY_SUBSCRIPTION } from './Subscription';
+import { Observer, SubscriptionLike, TeardownLogic } from './types';
+import { ObjectUnsubscribedError } from './util/ObjectUnsubscribedError';
+import { arrRemove } from './util/arrRemove';
+import { errorContext } from './util/errorContext';
+
+/**
+ * A Subject is a special type of Observable that allows values to be
+ * multicasted to many Observers. Subjects are like EventEmitters.
+ *
+ * Every Subject is an Observable and an Observer. You can subscribe to a
+ * Subject, and you can call next to feed values as well as error and complete.
+ */
+export class Subject<T> extends Observable<T> implements SubscriptionLike {
+  closed = false;
+
+  private currentObservers: Observer<T>[] | null = null;
+
+  /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */
+  observers: Observer<T>[] = [];
+  /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */
+  isStopped = false;
+  /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */
+  hasError = false;
+  /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */
+  thrownError: any = null;
+
+  /**
+   * Creates a "subject" by basically gluing an observer to an observable.
+   *
+   * @deprecated Recommended you do not use. Will be removed at some point in the future. Plans for replacement still under discussion.
+   */
+  static create: (...args: any[]) => any = <T>(destination: Observer<T>, source: Observable<T>): AnonymousSubject<T> => {
+    return new AnonymousSubject<T>(destination, source);
+  };
+
+  constructor() {
+    // NOTE: This must be here to obscure Observable's constructor.
+    super();
+  }
+
+  /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */
+  lift<R>(operator: Operator<T, R>): Observable<R> {
+    const subject = new AnonymousSubject(this, this);
+    subject.operator = operator as any;
+    return subject as any;
+  }
+
+  /** @internal */
+  protected _throwIfClosed() {
+    if (this.closed) {
+      throw new ObjectUnsubscribedError();
+    }
+  }
+
+  next(value: T) {
+    errorContext(() => {
+      this._throwIfClosed();
+      if (!this.isStopped) {
+        if (!this.currentObservers) {
+          this.currentObservers = Array.from(this.observers);
+        }
+        for (const observer of this.currentObservers) {
+          observer.next(value);
+        }
+      }
+    });
+  }
+
+  error(err: any) {
+    errorContext(() => {
+      this._throwIfClosed();
+      if (!this.isStopped) {
+        this.hasError = this.isStopped = true;
+        this.thrownError = err;
+        const { observers } = this;
+        while (observers.length) {
+          observers.shift()!.error(err);
+        }
+      }
+    });
+  }
+
+  complete() {
+    errorContext(() => {
+      this._throwIfClosed();
+      if (!this.isStopped) {
+        this.isStopped = true;
+        const { observers } = this;
+        while (observers.length) {
+          observers.shift()!.complete();
+        }
+      }
+    });
+  }
+
+  unsubscribe() {
+    this.isStopped = this.closed = true;
+    this.observers = this.currentObservers = null!;
+  }
+
+  get observed() {
+    return this.observers?.length > 0;
+  }
+
+  /** @internal */
+  protected _trySubscribe(subscriber: Subscriber<T>): TeardownLogic {
+    this._throwIfClosed();
+    return super._trySubscribe(subscriber);
+  }
+
+  /** @internal */
+  protected _subscribe(subscriber: Subscriber<T>): Subscription {
+    this._throwIfClosed();
+    this._checkFinalizedStatuses(subscriber);
+    return this._innerSubscribe(subscriber);
+  }
+
+  /** @internal */
+  protected _innerSubscribe(subscriber: Subscriber<any>) {
+    const { hasError, isStopped, observers } = this;
+    if (hasError || isStopped) {
+      return EMPTY_SUBSCRIPTION;
+    }
+    this.currentObservers = null;
+    observers.push(subscriber);
+    return new Subscription(() => {
+      this.currentObservers = null;
+      arrRemove(observers, subscriber);
+    });
+  }
+
+  /** @internal */
+  protected _checkFinalizedStatuses(subscriber: Subscriber<any>) {
+    const { hasError, thrownError, isStopped } = this;
+    if (hasError) {
+      subscriber.error(thrownError);
+    } else if (isStopped) {
+      subscriber.complete();
+    }
+  }
+
+  /**
+   * Creates a new Observable with this Subject as the source. You can do this
+   * to create custom Observer-side logic of the Subject and conceal it from
+   * code that uses the Observable.
+   * @return Observable that this Subject casts to.
+   */
+  asObservable(): Observable<T> {
+    const observable: any = new Observable<T>();
+    observable.source = this;
+    return observable;
+  }
+}
+
+export class AnonymousSubject<T> extends Subject<T> {
+  constructor(
+    /** @deprecated Internal implementation detail, do not use directly. Will be made internal in v8. */
+    public destination?: Observer<T>,
+    source?: Observable<T>
+  ) {
+    super();
+    this.source = source;
+  }
+
+  next(value: T) {
+    this.destination?.next?.(value);
+  }
+
+  error(err: any) {
+    this.destination?.error?.(err);
+  }
+
+  complete() {
+    this.destination?.complete?.();
+  }
+
+  /** @internal */
+  protected _subscribe(subscriber: Subscriber<T>): Subscription {
+    return this.source?.subscribe(subscriber) ?? EMPTY_SUBSCRIPTION;
+  }
+}