From d31dc7b2b3989d78c1b9c57818ed2a435fe9e23c Mon Sep 17 00:00:00 2001
From: Georgios Kalpakas <kalpakas.g@gmail.com>
Date: Thu, 20 Jul 2017 19:06:13 +0300
Subject: [PATCH] fix(upgrade): throw error if trying to get injector before
 setting (#18209)

Previously, `undefined` would be returned.
This change makes it easier to identify incorrect uses/bugs.
(Discussed in https://github.com/angular/angular/pull/18213#issuecomment-316191308.)
---
 packages/upgrade/src/static/angular1_providers.ts       | 4 ++++
 packages/upgrade/test/static/angular1_providers_spec.ts | 8 ++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/packages/upgrade/src/static/angular1_providers.ts b/packages/upgrade/src/static/angular1_providers.ts
index 46cc052a8d..36c8187cae 100644
--- a/packages/upgrade/src/static/angular1_providers.ts
+++ b/packages/upgrade/src/static/angular1_providers.ts
@@ -17,6 +17,10 @@ export function setTempInjectorRef(injector: angular.IInjectorService) {
   tempInjectorRef = injector;
 }
 export function injectorFactory() {
+  if (!tempInjectorRef) {
+    throw new Error('Trying to get the AngularJS injector before it being set.');
+  }
+
   const injector: angular.IInjectorService|null = tempInjectorRef;
   tempInjectorRef = null;  // clear the value to prevent memory leaks
   return injector;
diff --git a/packages/upgrade/test/static/angular1_providers_spec.ts b/packages/upgrade/test/static/angular1_providers_spec.ts
index 94ac3068eb..85c3d98d9e 100644
--- a/packages/upgrade/test/static/angular1_providers_spec.ts
+++ b/packages/upgrade/test/static/angular1_providers_spec.ts
@@ -28,12 +28,16 @@ export function main() {
         expect(injector).toBe(mockInjector);
       });
 
+      it('should throw if the injector value has not been set yet', () => {
+        const mockInjector = {get: () => {}, has: () => false};
+        expect(injectorFactory).toThrowError();
+      });
+
       it('should unset the injector after the first call (to prevent memory leaks)', () => {
         const mockInjector = {get: () => {}, has: () => false};
         setTempInjectorRef(mockInjector);
         injectorFactory();
-        const injector = injectorFactory();
-        expect(injector).toBe(null);
+        expect(injectorFactory).toThrowError();  // ...because it has been unset
       });
     });