From d470dff03488df9b5de3f0e5f9acfa2dcf33da3c Mon Sep 17 00:00:00 2001
From: Artur Androsovych <arthurandrosovich@gmail.com>
Date: Mon, 28 Feb 2022 21:25:12 +0200
Subject: [PATCH] perf(store): tree-shake `deepFreeze` (#1821)

---
 CHANGELOG.md                                  |  1 +
 bundlesize.config.json                        | 10 +++++-----
 .../store/src/internal/state-operations.ts    | 20 +++++++++++++++----
 packages/store/src/symbols.ts                 |  3 +++
 4 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 27ab97401..e81cb59aa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ $ npm install @ngxs/store@dev
 - Performance: Tree-shake errors and warnings [#1732](https://github.com/ngxs/store/pull/1732)
 - Performance: Tree-shake `ConfigValidator`, `HostEnvironment` and `isAngularInTestMode` [#1741](https://github.com/ngxs/store/pull/1741)
 - Performance: Tree-shake `SelectFactory` [#1744](https://github.com/ngxs/store/pull/1744)
+- Performance: Tree-shake `deepFreeze` [#1819](https://github.com/ngxs/store/pull/1819)
 - Performance: Router Plugin - Tree-shake `isAngularInTestMode()` [#1738](https://github.com/ngxs/store/pull/1738)
 - Performance: Tree-shake `isAngularInTestMode()` [#1739](https://github.com/ngxs/store/pull/1739)
 - Performance: Storage Plugin - Tree-shake `console.*` calls and expand error messages [#1727](https://github.com/ngxs/store/pull/1727)
diff --git a/bundlesize.config.json b/bundlesize.config.json
index a927b85a8..023fc9af2 100644
--- a/bundlesize.config.json
+++ b/bundlesize.config.json
@@ -32,14 +32,14 @@
       "path": "./@ngxs/store/fesm2015/ngxs-store.js",
       "package": "@ngxs/store",
       "target": "es2015",
-      "maxSize": "113.70KB",
+      "maxSize": "114.70KB",
       "compression": "none"
     },
     {
       "path": "./@ngxs/store/fesm5/ngxs-store.js",
       "package": "@ngxs/store",
       "target": "es5",
-      "maxSize": "132.60KB",
+      "maxSize": "133.60KB",
       "compression": "none"
     },
     {
@@ -143,19 +143,19 @@
     {
       "path": "./integrations/hello-world-ng11-ivy/dist-integration/main.*.js",
       "target": "es2015",
-      "maxSize": "251.30 kB",
+      "maxSize": "250.90 kB",
       "compression": "none"
     },
     {
       "path": "./integrations/hello-world-ng12-ivy/dist-integration/main.*.js",
       "target": "es2015",
-      "maxSize": "236.90 kB",
+      "maxSize": "236.50 kB",
       "compression": "none"
     },
     {
       "path": "./integrations/hello-world-ng13-ivy/dist-integration/main.*.js",
       "target": "es2015",
-      "maxSize": "237.20 kB",
+      "maxSize": "236.80 kB",
       "compression": "none"
     }
   ]
diff --git a/packages/store/src/internal/state-operations.ts b/packages/store/src/internal/state-operations.ts
index 67ce26907..df17e9bc0 100644
--- a/packages/store/src/internal/state-operations.ts
+++ b/packages/store/src/internal/state-operations.ts
@@ -1,4 +1,5 @@
 import { Injectable } from '@angular/core';
+import { isAngularInTestMode } from '@ngxs/store/internals';
 
 import { StateOperations, StatesAndDefaults } from '../internal/internals';
 import { InternalDispatcher } from '../internal/dispatcher';
@@ -28,9 +29,21 @@ export class InternalStateOperations {
       dispatch: (actionOrActions: any | any[]) => this._dispatcher.dispatch(actionOrActions)
     };
 
-    return this._config.developmentMode
-      ? ensureStateAndActionsAreImmutable(rootStateOperations)
-      : rootStateOperations;
+    // We have to have that duplication since this will allow us to tree-shake `ensureStateAndActionsAreImmutable`
+    // and `deepFreeze` in Ivy production build.
+    // The below `if` condition checks 2 things:
+    // 1) if we're in View Engine (`ngDevMode` is `undefined`)
+    // 2) if we're running tests, we should fallback to `config.developmentMode` to be backwards-compatible
+    if (typeof ngDevMode === 'undefined' || (ngDevMode && isAngularInTestMode())) {
+      return this._config.developmentMode
+        ? ensureStateAndActionsAreImmutable(rootStateOperations)
+        : rootStateOperations;
+    } else {
+      // If we're in Ivy and not running tests, then tree-shake `ensureStateAndActionsAreImmutable` and `deepFreeze`.
+      return ngDevMode
+        ? ensureStateAndActionsAreImmutable(rootStateOperations)
+        : rootStateOperations;
+    }
   }
 
   setStateToTheCurrentWithNew(results: StatesAndDefaults): void {
@@ -43,7 +56,6 @@ export class InternalStateOperations {
   }
 }
 
-// We make it as a separate function and not the class method to tree-shake it in the future.
 function ensureStateAndActionsAreImmutable(root: StateOperations<any>): StateOperations<any> {
   return {
     getState: () => root.getState(),
diff --git a/packages/store/src/symbols.ts b/packages/store/src/symbols.ts
index 9e67a9c3f..8a1e26e76 100644
--- a/packages/store/src/symbols.ts
+++ b/packages/store/src/symbols.ts
@@ -30,6 +30,9 @@ export class NgxsConfig {
    * Run in development mode. This will add additional debugging features:
    * - Object.freeze on the state and actions to guarantee immutability
    * (default: false)
+   *
+   * @deprecated This property is no longer necessary when the Ivy compiler is used.
+   * We'll determine the development mode through the `ngDevMode`. It's still essential with View Engine.
    */
   developmentMode: boolean;
   compatibility: {