From 722145cf072eb4041711c1a0799acc186c94b8cf Mon Sep 17 00:00:00 2001
From: Arman Ozak <arman@armanozak.com>
Date: Fri, 28 Aug 2020 17:25:00 +0300
Subject: [PATCH] feat: add chainAndMerge utility rule creator

---
 npm/ng-packs/packages/schematics/src/utils/rule.ts | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/npm/ng-packs/packages/schematics/src/utils/rule.ts b/npm/ng-packs/packages/schematics/src/utils/rule.ts
index 6748f30fab..39b14cec78 100644
--- a/npm/ng-packs/packages/schematics/src/utils/rule.ts
+++ b/npm/ng-packs/packages/schematics/src/utils/rule.ts
@@ -1,6 +1,8 @@
 import {
   apply,
+  chain,
   forEach,
+  MergeStrategy,
   mergeWith,
   Rule,
   SchematicContext,
@@ -16,6 +18,14 @@ export function applyWithOverwrite(source: Source, rules: Rule[]): Rule {
   };
 }
 
+export function chainAndMerge(rules: Rule[]) {
+  return (host: Tree) => async (tree: Tree, context: SchematicContext) =>
+    host.merge(
+      (await (chain(rules)(tree, context) as any).toPromise()) as Tree,
+      MergeStrategy.AllowDeleteConflict,
+    );
+}
+
 export function overwriteFileIfExists(tree: Tree): Rule {
   return forEach(fileEntry => {
     if (!tree.exists(fileEntry.path)) return fileEntry;