From 9558ac7d5523aa2e3733ebd3334eaed62898fc40 Mon Sep 17 00:00:00 2001
From: Todd Volkert <tvolkert@users.noreply.github.com>
Date: Wed, 26 Apr 2017 21:35:58 -0700
Subject: [PATCH] Assert that url is non-null in NetworkImage (#9626)

---
 .../flutter/lib/src/services/image_provider.dart   |  2 +-
 .../flutter/test/services/image_provider_test.dart | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 packages/flutter/test/services/image_provider_test.dart

diff --git a/packages/flutter/lib/src/services/image_provider.dart b/packages/flutter/lib/src/services/image_provider.dart
index f6e0d88c33d..bc9423e3df9 100644
--- a/packages/flutter/lib/src/services/image_provider.dart
+++ b/packages/flutter/lib/src/services/image_provider.dart
@@ -311,7 +311,7 @@ class NetworkImage extends ImageProvider<NetworkImage> {
   /// Creates an object that fetches the image at the given URL.
   ///
   /// The arguments must not be null.
-  const NetworkImage(this.url, { this.scale: 1.0 });
+  const NetworkImage(this.url, { this.scale: 1.0 }) : assert(url != null);
 
   /// The URL from which the image will be fetched.
   final String url;
diff --git a/packages/flutter/test/services/image_provider_test.dart b/packages/flutter/test/services/image_provider_test.dart
new file mode 100644
index 00000000000..4517c266a56
--- /dev/null
+++ b/packages/flutter/test/services/image_provider_test.dart
@@ -0,0 +1,14 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('NetworkImage non-null url test', () {
+    expect(() {
+      new NetworkImage(null); // ignore: prefer_const_constructors
+    }, throwsAssertionError);
+  });
+}