initial commit: scaffolding

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diff --git a/node_modules/rxjs/src/internal/operators/debounceTime.ts b/node_modules/rxjs/src/internal/operators/debounceTime.ts
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+import { asyncScheduler } from '../scheduler/async';
+import { Subscription } from '../Subscription';
+import { MonoTypeOperatorFunction, SchedulerAction, SchedulerLike } from '../types';
+import { operate } from '../util/lift';
+import { createOperatorSubscriber } from './OperatorSubscriber';
+
+/**
+ * Emits a notification from the source Observable only after a particular time span
+ * has passed without another source emission.
+ *
+ * <span class="informal">It's like {@link delay}, but passes only the most
+ * recent notification from each burst of emissions.</span>
+ *
+ * ![](debounceTime.png)
+ *
+ * `debounceTime` delays notifications emitted by the source Observable, but drops
+ * previous pending delayed emissions if a new notification arrives on the source
+ * Observable. This operator keeps track of the most recent notification from the
+ * source Observable, and emits that only when `dueTime` has passed
+ * without any other notification appearing on the source Observable. If a new value
+ * appears before `dueTime` silence occurs, the previous notification will be dropped
+ * and will not be emitted and a new `dueTime` is scheduled.
+ * If the completing event happens during `dueTime` the last cached notification
+ * is emitted before the completion event is forwarded to the output observable.
+ * If the error event happens during `dueTime` or after it only the error event is
+ * forwarded to the output observable. The cache notification is not emitted in this case.
+ *
+ * This is a rate-limiting operator, because it is impossible for more than one
+ * notification to be emitted in any time window of duration `dueTime`, but it is also
+ * a delay-like operator since output emissions do not occur at the same time as
+ * they did on the source Observable. Optionally takes a {@link SchedulerLike} for
+ * managing timers.
+ *
+ * ## Example
+ *
+ * Emit the most recent click after a burst of clicks
+ *
+ * ```ts
+ * import { fromEvent, debounceTime } from 'rxjs';
+ *
+ * const clicks = fromEvent(document, 'click');
+ * const result = clicks.pipe(debounceTime(1000));
+ * result.subscribe(x => console.log(x));
+ * ```
+ *
+ * @see {@link audit}
+ * @see {@link auditTime}
+ * @see {@link debounce}
+ * @see {@link sample}
+ * @see {@link sampleTime}
+ * @see {@link throttle}
+ * @see {@link throttleTime}
+ *
+ * @param dueTime The timeout duration in milliseconds (or the time unit determined
+ * internally by the optional `scheduler`) for the window of time required to wait
+ * for emission silence before emitting the most recent source value.
+ * @param scheduler The {@link SchedulerLike} to use for managing the timers that
+ * handle the timeout for each value.
+ * @return A function that returns an Observable that delays the emissions of
+ * the source Observable by the specified `dueTime`, and may drop some values
+ * if they occur too frequently.
+ */
+export function debounceTime<T>(dueTime: number, scheduler: SchedulerLike = asyncScheduler): MonoTypeOperatorFunction<T> {
+  return operate((source, subscriber) => {
+    let activeTask: Subscription | null = null;
+    let lastValue: T | null = null;
+    let lastTime: number | null = null;
+
+    const emit = () => {
+      if (activeTask) {
+        // We have a value! Free up memory first, then emit the value.
+        activeTask.unsubscribe();
+        activeTask = null;
+        const value = lastValue!;
+        lastValue = null;
+        subscriber.next(value);
+      }
+    };
+    function emitWhenIdle(this: SchedulerAction<unknown>) {
+      // This is called `dueTime` after the first value
+      // but we might have received new values during this window!
+
+      const targetTime = lastTime! + dueTime;
+      const now = scheduler.now();
+      if (now < targetTime) {
+        // On that case, re-schedule to the new target
+        activeTask = this.schedule(undefined, targetTime - now);
+        subscriber.add(activeTask);
+        return;
+      }
+
+      emit();
+    }
+
+    source.subscribe(
+      createOperatorSubscriber(
+        subscriber,
+        (value: T) => {
+          lastValue = value;
+          lastTime = scheduler.now();
+
+          // Only set up a task if it's not already up
+          if (!activeTask) {
+            activeTask = scheduler.schedule(emitWhenIdle, dueTime);
+            subscriber.add(activeTask);
+          }
+        },
+        () => {
+          // Source completed.
+          // Emit any pending debounced values then complete
+          emit();
+          subscriber.complete();
+        },
+        // Pass all errors through to consumer.
+        undefined,
+        () => {
+          // Finalization.
+          lastValue = activeTask = null;
+        }
+      )
+    );
+  });
+}