From bdf5f3e499847ca30df4a5c0dd9f1465b91b9e5b Mon Sep 17 00:00:00 2001
From: Alex Rickabaugh <alx+alxhub@alxandria.net>
Date: Mon, 26 Nov 2018 14:27:39 -0800
Subject: [PATCH] fix(core): export a value for InjectFlags (#27279)

A recent commit (probably 2c7386c) has changed the import graph of the
DI types in core, and somehow results in the ngc compiler deciding to
re-export core DI types from application factories which tangentially
use inject(). This is not really surprising; ngc's import graph can be
very unstable.

However, this results in a re-export of InjectFlags surviving JS
compilation. InjectFlags was a const enum, akin to an interface in TS,
with no runtime repesentation. This causes a warning to be emitted by
Webpack when it sees the re-export of InjectFlags.

This commit avoids the issue by removing 'const' from the declaration
of InjectFlags, causing it to have a runtime value. This is a temporary
fix. The real fix will be for ngc to no longer write exports of const
enums.

Testing strategy: manually verified. Due to the problem only manifesting
when recompiling after a change and then running Webpack, there is no
existing framework via which this could be easily tested with an
integration test. Additionally, the potential for this issue is gone in
Ivy, so this solution is only temporarily needed.

Fixes #27251.

PR Close #27279
---
 packages/core/src/di/injector_compatibility.ts                | 4 +++-
 .../test/bundling/animation_world/bundle.golden_symbols.json  | 3 +++
 .../test/bundling/hello_world_r2/bundle.golden_symbols.json   | 3 +++
 .../core/test/bundling/injection/bundle.golden_symbols.json   | 3 +++
 packages/core/test/bundling/todo/bundle.golden_symbols.json   | 3 +++
 .../core/test/bundling/todo_r2/bundle.golden_symbols.json     | 3 +++
 tools/public_api_guard/core/core.d.ts                         | 2 +-
 7 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/packages/core/src/di/injector_compatibility.ts b/packages/core/src/di/injector_compatibility.ts
index 78a30ae32f..3eb5b47c3e 100644
--- a/packages/core/src/di/injector_compatibility.ts
+++ b/packages/core/src/di/injector_compatibility.ts
@@ -19,7 +19,9 @@ import {Inject, Optional, Self, SkipSelf} from './metadata';
  *
  * @publicApi
  */
-export const enum InjectFlags {
+export enum InjectFlags {
+  // TODO(alxhub): make this 'const' when ngc no longer writes exports of it into ngfactory files.
+
   Default = 0b0000,
 
   /**
diff --git a/packages/core/test/bundling/animation_world/bundle.golden_symbols.json b/packages/core/test/bundling/animation_world/bundle.golden_symbols.json
index 8007265b47..1d2048935c 100644
--- a/packages/core/test/bundling/animation_world/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/animation_world/bundle.golden_symbols.json
@@ -86,6 +86,9 @@
   {
     "name": "INJECTOR_SIZE"
   },
+  {
+    "name": "InjectFlags"
+  },
   {
     "name": "IterableChangeRecord_"
   },
diff --git a/packages/core/test/bundling/hello_world_r2/bundle.golden_symbols.json b/packages/core/test/bundling/hello_world_r2/bundle.golden_symbols.json
index 84bb286881..235a7d6bf6 100644
--- a/packages/core/test/bundling/hello_world_r2/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/hello_world_r2/bundle.golden_symbols.json
@@ -176,6 +176,9 @@
   {
     "name": "Inject"
   },
+  {
+    "name": "InjectFlags"
+  },
   {
     "name": "InjectionToken"
   },
diff --git a/packages/core/test/bundling/injection/bundle.golden_symbols.json b/packages/core/test/bundling/injection/bundle.golden_symbols.json
index c9d8c5f334..48f070ca93 100644
--- a/packages/core/test/bundling/injection/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/injection/bundle.golden_symbols.json
@@ -17,6 +17,9 @@
   {
     "name": "Inject"
   },
+  {
+    "name": "InjectFlags"
+  },
   {
     "name": "InjectionToken"
   },
diff --git a/packages/core/test/bundling/todo/bundle.golden_symbols.json b/packages/core/test/bundling/todo/bundle.golden_symbols.json
index 427f0c9959..98817f6924 100644
--- a/packages/core/test/bundling/todo/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/todo/bundle.golden_symbols.json
@@ -74,6 +74,9 @@
   {
     "name": "INJECTOR_SIZE"
   },
+  {
+    "name": "InjectFlags"
+  },
   {
     "name": "IterableChangeRecord_"
   },
diff --git a/packages/core/test/bundling/todo_r2/bundle.golden_symbols.json b/packages/core/test/bundling/todo_r2/bundle.golden_symbols.json
index 6e0a529556..88eba8185f 100644
--- a/packages/core/test/bundling/todo_r2/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/todo_r2/bundle.golden_symbols.json
@@ -371,6 +371,9 @@
   {
     "name": "Inject"
   },
+  {
+    "name": "InjectFlags"
+  },
   {
     "name": "InjectionToken"
   },
diff --git a/tools/public_api_guard/core/core.d.ts b/tools/public_api_guard/core/core.d.ts
index 2b0c1cb026..2d34bab8e5 100644
--- a/tools/public_api_guard/core/core.d.ts
+++ b/tools/public_api_guard/core/core.d.ts
@@ -347,7 +347,7 @@ export interface InjectDecorator {
     new (token: any): Inject;
 }
 
-export declare const enum InjectFlags {
+export declare enum InjectFlags {
     Default = 0,
     Host = 1,
     Self = 2,