Initial project import

node_modules/rxjs/src/internal/operators/joinAllInternals.ts

@@ -0,0 +1,29 @@
+import { Observable } from '../Observable';
+import { ObservableInput, OperatorFunction } from '../types';
+import { identity } from '../util/identity';
+import { mapOneOrManyArgs } from '../util/mapOneOrManyArgs';
+import { pipe } from '../util/pipe';
+import { mergeMap } from './mergeMap';
+import { toArray } from './toArray';
+
+/**
+ * Collects all of the inner sources from source observable. Then, once the
+ * source completes, joins the values using the given static.
+ *
+ * This is used for {@link combineLatestAll} and {@link zipAll} which both have the
+ * same behavior of collecting all inner observables, then operating on them.
+ *
+ * @param joinFn The type of static join to apply to the sources collected
+ * @param project The projection function to apply to the values, if any
+ */
+export function joinAllInternals<T, R>(joinFn: (sources: ObservableInput<T>[]) => Observable<T>, project?: (...args: any[]) => R) {
+  return pipe(
+    // Collect all inner sources into an array, and emit them when the
+    // source completes.
+    toArray() as OperatorFunction<ObservableInput<T>, ObservableInput<T>[]>,
+    // Run the join function on the collected array of inner sources.
+    mergeMap((sources) => joinFn(sources)),
+    // If a projection function was supplied, apply it to each result.
+    project ? mapOneOrManyArgs(project) : (identity as any)
+  );
+}