From b645e4ea3c6d39f6ce274a334bcaa33817baa3ea Mon Sep 17 00:00:00 2001
From: Zachary Anderson <zanderso@users.noreply.github.com>
Date: Mon, 17 Apr 2017 15:21:12 -0700
Subject: [PATCH] [fuchsia_reload] Fix command line argument checking (#9434)

---
 .../flutter_tools/lib/src/commands/fuchsia_reload.dart   | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/packages/flutter_tools/lib/src/commands/fuchsia_reload.dart b/packages/flutter_tools/lib/src/commands/fuchsia_reload.dart
index befbbaf566..3dcbf92c5b 100644
--- a/packages/flutter_tools/lib/src/commands/fuchsia_reload.dart
+++ b/packages/flutter_tools/lib/src/commands/fuchsia_reload.dart
@@ -195,9 +195,12 @@ class FuchsiaReloadCommand extends FlutterCommand {
       return;
     }
 
-    final List<String> gnTarget = _extractPathAndName(argResults['gn-target']);
-    _projectRoot = gnTarget[0];
-    _projectName = gnTarget[1];
+    final String gnTarget = argResults['gn-target'];
+    if (gnTarget == null)
+      throwToolExit('Give the GN target with --gn-target(-g).');
+    final List<String> targetInfo = _extractPathAndName(gnTarget);
+    _projectRoot = targetInfo[0];
+    _projectName = targetInfo[1];
     _fuchsiaProjectPath = '$_fuchsiaRoot/$_projectRoot';
     if (!_directoryExists(_fuchsiaProjectPath))
       throwToolExit('Target does not exist in the Fuchsia tree: $_fuchsiaProjectPath.');