Merge 56a5fac into d631261

src/array/operators/transformation/array-concat.operator.spec.ts

@@ -0,0 +1,41 @@
+import { TestScheduler } from 'rxjs/testing';
+
+import { arrayConcat } from './array-concat.operator';
+
+describe('array/operators/switch-expand-items', () => {
+  let testScheduler: TestScheduler;
+
+  beforeEach(() => {
+    testScheduler = new TestScheduler((actual, expected) => {
+      expect(actual).toEqual(expected);
+    });
+  });
+
+  const inputValues = {
+    a: [['a']],
+    b: [['a'], ['b']],
+    c: [['a'], ['b'], ['c']],
+    d: [
+      ['a', 'b'],
+      ['c', 'd'],
+    ],
+    e: [['a', 'b'], ['c', 'd'], ['e']],
+  };
+
+  const arrayValues = {
+    a: ['a'],
+    b: ['a', 'b'],
+    c: ['a', 'b', 'c'],
+    d: ['a', 'b', 'c', 'd'],
+    e: ['a', 'b', 'c', 'd', 'e'],
+  };
+
+  it('should concat array emissions', () => {
+    testScheduler.run(({ expectObservable, cold }) => {
+      const marbles = '(abc|)';
+      const source$ = cold(marbles, inputValues).pipe(arrayConcat());
+
+      expectObservable(source$).toBe(marbles, arrayValues);
+    });
+  });
+});

src/array/operators/transformation/array-concat.operator.ts

@@ -0,0 +1,15 @@
+import { OperatorFunction } from 'rxjs';
+import { map } from 'rxjs/operators';
+
+/**
+ * @returns
+ * An operator that collects streams of arrays and
+ * emits an concatted array of the sources emission
+ *
+ * @example
+ * combineLatest([of(['a']), of(['b', 'c']), of(['d'])]).pipe(arrayConcat());
+ * // (a|) -> a: ['a', 'b', 'c', 'd']
+ */
+export function arrayConcat<T>(): OperatorFunction<T[][], T[]> {
+  return map(values => values.reduce((acc, cur) => [...acc, ...cur], []));
+}

src/array/operators/transformation/collect-array.operator.spec.ts

@@ -1,4 +1,3 @@
-import { toArray } from 'rxjs/operators';
 import { TestScheduler } from 'rxjs/testing';
 
 import { collectArray } from './collect-array.operator';

src/array/operators/transformation/index.ts

@@ -1,3 +1,4 @@
+export * from './array-concat.operator';
 export * from './collect-array.operator';
 export * from './map-filter.operator';
 export * from './map-items.operator';