From 9461df16f71186ea40b365622900b03d7f7bb387 Mon Sep 17 00:00:00 2001
From: Dan Percic <dan@devplant.ro>
Date: Fri, 22 Oct 2021 00:07:42 +0300
Subject: [PATCH] add filterEach operator

---
 src/lib/utils/operators.ts | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/lib/utils/operators.ts b/src/lib/utils/operators.ts
index c7580e9..a8de46e 100644
--- a/src/lib/utils/operators.ts
+++ b/src/lib/utils/operators.ts
@@ -1,17 +1,21 @@
 import { distinctUntilChanged, map } from 'rxjs/operators';
 import { OperatorFunction, pipe } from 'rxjs';
 
-export function get<T>(predicate: (value: T, index: number) => boolean): OperatorFunction<T[], T | undefined> {
+export function get<T>(predicate: (value: T, index: number) => boolean): OperatorFunction<readonly T[], T | undefined> {
     return map(entities => entities.find(predicate));
 }
 
-export function any<T>(predicate: (value: T, index: number) => boolean): OperatorFunction<T[], boolean> {
+export function any<T>(predicate: (value: T, index: number) => boolean): OperatorFunction<readonly T[], boolean> {
     return map(entities => entities.some(predicate));
 }
 
-export function mapEach<T, R>(predicate: (value: T, index: number) => R): OperatorFunction<T[], R[]> {
+export function mapEach<T, R>(predicate: (value: T, index: number) => R): OperatorFunction<readonly T[], R[]> {
     return map(entities => entities.map(predicate));
 }
 
+export function filterEach<T>(predicate: (value: T, index: number) => boolean): OperatorFunction<readonly T[], T[]> {
+    return map(entities => entities.filter(predicate));
+}
+
 export const toLengthValue = (entities: unknown[]): number => entities?.length ?? 0;
 export const getLength = pipe(map(toLengthValue), distinctUntilChanged());