Change Process.start to return a future that completes with a

tests/standalone/io/dart_std_io_pipe_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Test a dart sub-process handling stdio with different types of
 // redirection.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
@@ skipping 22 matching lines @@
 void test(String shellScript, String dartScript, String type) {
   Directory dir = new Directory("").createTempSync();
 
   // The shell script will run the dart executable passed with a
   // number of different redirections of stdio.
   String pipeOutFile = "${dir.path}/pipe";
   String redirectOutFile = "${dir.path}/redirect";
   String executable = new Options().executable;
   List args =
       [executable, dartScript, type, pipeOutFile, redirectOutFile];
-  Process process = Process.start(shellScript, args);
+  var future = Process.start(shellScript, args);
+  future.then((process) {
+    process.onExit = (exitCode) {
+      Expect.equals(0, exitCode);
+      process.close();
 
-  // Wait for the process to exit and then check result.
-  process.onExit = (exitCode) {
-    Expect.equals(0, exitCode);
-    process.close();
+      // Check the expected file contents.
+      if (type == "0") {
+        checkFileContent("${pipeOutFile}", "Hello\n");
+        checkFileEmpty("${redirectOutFile}.stderr");
+        checkFileContent("${redirectOutFile}.stdout", "Hello\nHello\n");
+      }
+      if (type == "1") {
+        checkFileContent("${pipeOutFile}", "Hello\n");
+        checkFileEmpty("${redirectOutFile}.stdout");
+        checkFileContent("${redirectOutFile}.stderr", "Hello\nHello\n");
+      }
+      if (type == "2") {
+        checkFileContent("${pipeOutFile}", "Hello\nHello\n");
+        checkFileContent("${redirectOutFile}.stdout",
+                         "Hello\nHello\nHello\nHello\n");
+        checkFileContent("${redirectOutFile}.stderr",
+                         "Hello\nHello\nHello\nHello\n");
+      }
 
-    // Check the expected file contents.
-    if (type == "0") {
-      checkFileContent("${pipeOutFile}", "Hello\n");
-      checkFileEmpty("${redirectOutFile}.stderr");
-      checkFileContent("${redirectOutFile}.stdout", "Hello\nHello\n");
-    }
-    if (type == "1") {
-      checkFileContent("${pipeOutFile}", "Hello\n");
-      checkFileEmpty("${redirectOutFile}.stdout");
-      checkFileContent("${redirectOutFile}.stderr", "Hello\nHello\n");
-    }
-    if (type == "2") {
-      checkFileContent("${pipeOutFile}", "Hello\nHello\n");
-      checkFileContent("${redirectOutFile}.stdout",
-                       "Hello\nHello\nHello\nHello\n");
-      checkFileContent("${redirectOutFile}.stderr",
-                       "Hello\nHello\nHello\nHello\n");
-    }
-
-    // Cleanup test directory.
-    dir.deleteRecursivelySync();
-  };
-
-  process.onError = (ProcessException error) {
+      // Cleanup test directory.
+      dir.deleteRecursivelySync();
+    };
+  });
+  future.handleException((ProcessException error) {
     Expect.fail(error.toString());

[ricow1, 2012/10/11 17:27:34]

we should probably do a dir.deleteRecursivelySync() in here as well, otherwise
this will be leftover if this fails.

[Mads Ager (google), 2012/10/12 08:44:46]

Done for this particular test. I'm pretty sure that we do not clean up on
failures in most of the file/directory tests. 

-  };
+  });
 }
 
 // This tests that the Dart standalone VM can handle piping to stdin
 // and can pipe to stdout.
 main() {
   // Don't try to run shell scripts on Windows.
   var os = Platform.operatingSystem;
   if (os == 'windows') return;
 
   // Get the shell script for testing the Standalone Dart VM with
   // piping and redirections of stdio.
   var shellScript = new File("tests/standalone/io/dart_std_io_pipe_test.sh");
   if (!shellScript.existsSync()) {
     shellScript = new File("../tests/standalone/io/dart_std_io_pipe_test.sh");
   }
   // Get the Dart script file which echoes stdin to stdout or stderr or both.
   var scriptFile = new File("tests/standalone/io/process_std_io_script.dart");
   if (!scriptFile.existsSync()) {
     scriptFile = new File("../tests/standalone/io/process_std_io_script.dart");
   }
 
   // Run the shell script.
   test(shellScript.name, scriptFile.name, "0");
   test(shellScript.name, scriptFile.name, "1");
   test(shellScript.name, scriptFile.name, "2");
 }