Cleanup lib/src/run_and_collect.dart

lib/src/run_and_collect.dart

diff --git a/lib/src/run_and_collect.dart b/lib/src/run_and_collect.dart
index b9a0932..1bd5790 100644
--- a/lib/src/run_and_collect.dart
+++ b/lib/src/run_and_collect.dart
@@ -16,31 +16,35 @@
   final dartArgs = [
     '--enable-vm-service',
     '--pause_isolates_on_exit',
+    if (checked) '--checked',
+    scriptPath,
+    ...?scriptArgs,
   ];
 
-  if (checked) {
-    dartArgs.add('--checked');
-  }
-
-  dartArgs.add(scriptPath);
-
-  if (scriptArgs != null) {
-    dartArgs.addAll(scriptArgs);
-  }
-
   final process = await Process.start(Platform.executable, dartArgs);
 
   final serviceUri = await serviceUriFromProcess(process.stdout.lines());
   Map<String, dynamic> coverage;
   try {
-    coverage = await collect(serviceUri, true, true, includeDart, <String>{},
-        timeout: timeout);
+    coverage = await collect(
+      serviceUri,
+      true,
+      true,
+      includeDart,
+      <String>{},
+      timeout: timeout,
+    );
   } finally {
     await process.stderr.drain();
   }
   final exitStatus = await process.exitCode;
   if (exitStatus != 0) {
-    throw 'Process exited with exit code $exitStatus';
+    throw ProcessException(
+      Platform.executable,
+      dartArgs,
+      'Process failed.',
+      exitStatus,
+    );
   }
   return coverage;
 }