From 5195ff487c0c2705676a87e6b8ea44a60685f303 Mon Sep 17 00:00:00 2001
From: Alan Agius <alan.agius4@gmail.com>
Date: Fri, 7 Aug 2020 14:56:13 +0200
Subject: [PATCH] fix(@ngtools/webpack): issue warning when using
 `strictMetadataEmit`

`strictMetadataEmit` option which is not intended to be used  for applications. See: https://angular.io/guide/angular-compiler-options#strictmetadataemit

Closes #18424
---
 packages/ngtools/webpack/src/angular_compiler_plugin.ts | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/packages/ngtools/webpack/src/angular_compiler_plugin.ts b/packages/ngtools/webpack/src/angular_compiler_plugin.ts
index 6bc056745611..316bec3df26c 100644
--- a/packages/ngtools/webpack/src/angular_compiler_plugin.ts
+++ b/packages/ngtools/webpack/src/angular_compiler_plugin.ts
@@ -275,6 +275,14 @@ export class AngularCompilerPlugin {
       );
     }
 
+    if (this._compilerOptions.strictMetadataEmit) {
+      this._warnings.push(
+        new Error(
+          `Using Angular compiler option 'strictMetadataEmit' for applications might cause undefined behavior.`,
+        ),
+      );
+    }
+
     if (this._discoverLazyRoutes === false && this.options.additionalLazyModules
       && Object.keys(this.options.additionalLazyModules).length > 0) {
       this._warnings.push(