More String + elimination in tests

tests/standalone/io/file_invalid_arguments_test.dart

Index: tests/standalone/io/file_invalid_arguments_test.dart
===================================================================
--- tests/standalone/io/file_invalid_arguments_test.dart	(revision 7745)
+++ tests/standalone/io/file_invalid_arguments_test.dart	(working copy)
@@ -89,7 +89,7 @@
 
   static void testWriteByteInvalidArgs(value) {
     String filename = getFilename("tests/vm/data/fixed_length_file");
-    var file = (new File(filename + "_out")).openSync(FileMode.WRITE);
+    var file = (new File(filename.concat("_out"))).openSync(FileMode.WRITE);

[siva, 2012/05/18 19:56:10]

Why do you use concat here and not:
new File("${filename}_out").openSync(FileMode.WRITE);

[hausner, 2012/05/18 21:03:46]

No particular reason, it just seemed more readable to me. If the code owners
don't like it, they can change it to use interpolation.

On 2012/05/18 19:56:10, asiva wrote:

     try {
       file.writeByteSync(value);
       Expect.fail('exception expected');
@@ -112,7 +112,7 @@
 
   static void testWriteListInvalidArgs(buffer, offset, bytes) {
     String filename = getFilename("tests/vm/data/fixed_length_file");
-    var file = (new File(filename + "_out")).openSync(FileMode.WRITE);
+    var file = (new File(filename.concat("_out"))).openSync(FileMode.WRITE);
     try {
       file.writeListSync(buffer, offset, bytes);
       Expect.fail('exception expected');
@@ -135,7 +135,7 @@
 
   static void testWriteStringInvalidArgs(string) {
     String filename = getFilename("tests/vm/data/fixed_length_file");
-    var file = new File(filename + "_out");
+    var file = new File(filename.concat("_out"));
     file.openSync(FileMode.WRITE);
     try {
       file.writeString(string);
@@ -181,7 +181,7 @@
   }
 
   static String getFilename(String path) =>
-      new File(path).existsSync() ? path : 'runtime/' + path;
+      new File(path).existsSync() ? path : 'runtime/$path';
 }
 
 main() {