From 71d4e8adf4148649727d139206df855b66a8f131 Mon Sep 17 00:00:00 2001
From: Charles Lyding <19598772+clydin@users.noreply.github.com>
Date: Mon, 29 Dec 2025 16:35:21 -0500
Subject: [PATCH 1/2] refactor(@angular/cli): add ignorePeerDependencies option
 to package manager

This commit adds support for ignoring peer dependency warnings and errors during package installation. This is useful for commands like `ng update` where transient peer dependency conflicts may occur.

- Added `ignorePeerDependenciesFlag` to the `PackageManagerDescriptor` interface.
- Implemented the flag for `npm` (`--legacy-peer-deps`) and `pnpm` (`--strict-peer-dependencies=false`).
- Updated `PackageManager.install` to accept and apply the `ignorePeerDependencies` option.
---
 .../cli/src/package-managers/package-manager-descriptor.ts   | 5 +++++
 packages/angular/cli/src/package-managers/package-manager.ts | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/packages/angular/cli/src/package-managers/package-manager-descriptor.ts b/packages/angular/cli/src/package-managers/package-manager-descriptor.ts
index f48ed1e32ed7..0a332653e01c 100644
--- a/packages/angular/cli/src/package-managers/package-manager-descriptor.ts
+++ b/packages/angular/cli/src/package-managers/package-manager-descriptor.ts
@@ -62,6 +62,9 @@ export interface PackageManagerDescriptor {
   /** The flag to prevent lifecycle scripts from being executed. */
   readonly ignoreScriptsFlag: string;
 
+  /** The flag to ignore peer dependency warnings/errors. */
+  readonly ignorePeerDependenciesFlag?: string;
+
   /** A function that returns the arguments and environment variables to use a custom registry. */
   readonly getRegistryOptions?: (registry: string) => {
     args?: string[];
@@ -140,6 +143,7 @@ export const SUPPORTED_PACKAGE_MANAGERS = {
     saveDevFlag: '--save-dev',
     noLockfileFlag: '--no-package-lock',
     ignoreScriptsFlag: '--ignore-scripts',
+    ignorePeerDependenciesFlag: '--legacy-peer-deps',
     getRegistryOptions: (registry: string) => ({ args: ['--registry', registry] }),
     versionCommand: ['--version'],
     listDependenciesCommand: ['list', '--depth=0', '--json=true', '--all=true'],
@@ -215,6 +219,7 @@ export const SUPPORTED_PACKAGE_MANAGERS = {
     saveDevFlag: '--save-dev',
     noLockfileFlag: '--no-lockfile',
     ignoreScriptsFlag: '--ignore-scripts',
+    ignorePeerDependenciesFlag: '--strict-peer-dependencies=false',
     getRegistryOptions: (registry: string) => ({ args: ['--registry', registry] }),
     versionCommand: ['--version'],
     listDependenciesCommand: ['list', '--depth=0', '--json'],
diff --git a/packages/angular/cli/src/package-managers/package-manager.ts b/packages/angular/cli/src/package-managers/package-manager.ts
index b76831be109c..57b521615273 100644
--- a/packages/angular/cli/src/package-managers/package-manager.ts
+++ b/packages/angular/cli/src/package-managers/package-manager.ts
@@ -308,11 +308,13 @@ export class PackageManager {
       force?: boolean;
       registry?: string;
       ignoreScripts?: boolean;
+      ignorePeerDependencies?: boolean;
     } = { ignoreScripts: true },
   ): Promise<void> {
     const flags = [
       options.force ? this.descriptor.forceFlag : '',
       options.ignoreScripts ? this.descriptor.ignoreScriptsFlag : '',
+      options.ignorePeerDependencies ? (this.descriptor.ignorePeerDependenciesFlag ?? '') : '',
     ].filter((flag) => flag);
     const args = [...this.descriptor.installCommand, ...flags];
 

From 944caf264b590fbc3b1ace94ac01d5012aeb9671 Mon Sep 17 00:00:00 2001
From: Charles Lyding <19598772+clydin@users.noreply.github.com>
Date: Mon, 29 Dec 2025 16:40:18 -0500
Subject: [PATCH 2/2] refactor(@angular/cli): use ignorePeerDependencies in
 update command

This commit updates the `ng update` command to utilize the `ignorePeerDependencies` option when installing packages. Previously, the command forced the installation (`--force`) when NPM 7+ was detected to workaround peer dependency issues. Now, it uses the more specific `ignorePeerDependencies` option (mapping to `--legacy-peer-deps` for NPM), which is safer and cleaner.
---
 packages/angular/cli/src/commands/update/cli.ts | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/packages/angular/cli/src/commands/update/cli.ts b/packages/angular/cli/src/commands/update/cli.ts
index 3de979b481e6..9b926cc079a2 100644
--- a/packages/angular/cli/src/commands/update/cli.ts
+++ b/packages/angular/cli/src/commands/update/cli.ts
@@ -521,7 +521,11 @@ export default class UpdateCommandModule extends CommandModule<UpdateCommandArgs
 
     if (success) {
       const { root: commandRoot } = this.context;
-      const force = await shouldForcePackageManager(packageManager, logger, options.verbose);
+      const ignorePeerDependencies = await shouldForcePackageManager(
+        packageManager,
+        logger,
+        options.verbose,
+      );
       const tasks = new Listr([
         {
           title: 'Cleaning node modules directory',
@@ -545,7 +549,7 @@ export default class UpdateCommandModule extends CommandModule<UpdateCommandArgs
           async task() {
             try {
               await packageManager.install({
-                force,
+                ignorePeerDependencies,
               });
             } catch (e) {
               throw new CommandError('Unable to install packages');
@@ -553,7 +557,6 @@ export default class UpdateCommandModule extends CommandModule<UpdateCommandArgs
           },
         },
       ]);
-
       try {
         await tasks.run();
       } catch (e) {