make crash server URL customizable from environment (#18649)

packages/flutter_tools/lib/src/crash_reporting.dart

@@ -37,14 +37,17 @@ const String _kStackTraceFileField = 'DartError';
 const String _kStackTraceFilename = 'stacktrace_file';
 
 /// Sends crash reports to Google.
+/// 
+/// There are two ways to override the behavior of this class:
+/// 
+/// * Define a `FLUTTER_CRASH_SERVER_BASE_URL` environment variable that points
+///   to a custom crash reporting server. This is useful if your development
+///   environment is behind a firewall and unable to send crash reports to
+///   Google, or when you wish to use your own server for collecting crash
+///   reports from Flutter Tools.
+/// * In tests call [initializeWith] and provide a mock implementation of
+///   [http.Client].
 class CrashReportSender {
-  static final Uri _baseUri = new Uri(
-      scheme: 'https',
-      host: _kCrashServerHost,
-      port: 443,
-      path: _kCrashEndpointPath,
-  );
-
   static CrashReportSender _instance;
 
   CrashReportSender._(this._client);
@@ -60,6 +63,20 @@ class CrashReportSender {
   final http.Client _client;
   final Usage _usage = Usage.instance;
 
+  Uri get _baseUrl {
+    final String overrideUrl = platform.environment['FLUTTER_CRASH_SERVER_BASE_URL'];
+
+    if (overrideUrl != null) {
+      return Uri.parse(overrideUrl);
+    }
+    return new Uri(
+      scheme: 'https',
+      host: _kCrashServerHost,
+      port: 443,
+      path: _kCrashEndpointPath,
+    );
+  }
+
   /// Sends one crash report.
   ///
   /// The report is populated from data in [error] and [stackTrace].
@@ -75,7 +92,7 @@ class CrashReportSender {
       printStatus('Sending crash report to Google.');
 
       final String flutterVersion = getFlutterVersion();
-      final Uri uri = _baseUri.replace(
+      final Uri uri = _baseUrl.replace(
         queryParameters: <String, String>{
           'product': _kProductId,
           'version': flutterVersion,

packages/flutter_tools/test/crash_reporting_test.dart

@@ -120,6 +120,45 @@ void main() {
     }, overrides: <Type, Generator>{
       Stdio: () => const _NoStderr(),
     });
+
+    testUsingContext('can override base URL', () async {
+      Uri uri;
+      CrashReportSender.initializeWith(new MockClient((Request request) async {
+        uri = request.url;
+        return new Response('test-report-id', 200);
+      }));
+
+      final int exitCode = await tools.run(
+        <String>['crash'],
+        <FlutterCommand>[new _CrashCommand()],
+        reportCrashes: true,
+        flutterVersion: 'test-version',
+      );
+
+      expect(exitCode, 1);
+
+      // Verify that we sent the crash report.
+      expect(uri, isNotNull);
+      expect(uri, new Uri(
+        scheme: 'https',
+        host: 'localhost',
+        port: 12345,
+        path: '/fake_server',
+        queryParameters: <String, String>{
+          'product': 'Flutter_Tools',
+          'version' : 'test-version',
+        },
+      ));
+    }, overrides: <Type, Generator> {
+      Platform: () => new FakePlatform(
+        operatingSystem: 'linux',
+        environment: <String, String>{
+          'FLUTTER_CRASH_SERVER_BASE_URL': 'https://localhost:12345/fake_server',
+        },
+        script: new Uri(scheme: 'data'),
+      ),
+      Stdio: () => const _NoStderr(),
+    });
   });
 }