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

tools/testing/dart/test_suite.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.
 
 /**
  * Classes and methods for enumerating and preparing tests.
  *
  * This library includes:
  *
  * - Creating tests by listing all the Dart files in certain directories,
@@ skipping 47 matching lines @@
   void forEachTest(TestCaseEvent onTest, Map testCache, [VoidFunction onDone]);
 }
 
 
 // TODO(1030): remove once in the corelib.
 bool Contains(element, collection) => collection.indexOf(element) >= 0;
 
 
 void ccTestLister() {
   port.receive((String runnerPath, SendPort replyTo) {
-    var p = Process.start(runnerPath, ["--list"]);
-    StringInputStream stdoutStream = new StringInputStream(p.stdout);
-    List<String> tests = new List<String>();
-    stdoutStream.onLine = () {
-      String line = stdoutStream.readLine();
-      while (line != null) {
-        tests.add(line);
-        line = stdoutStream.readLine();
-      }
-    };
-    p.onError = (error) {
+    void processErrorHandler(error) {
       print("Failed to list tests: $runnerPath --list");
       replyTo.send("");
-    };
-    p.onExit = (code) {
-      if (code < 0) {
-        print("Failed to list tests: $runnerPath --list");
+    }
+    Future processFuture = Process.start(runnerPath, ["--list"]);
+    processFuture.then((p) {
+      StringInputStream stdoutStream = new StringInputStream(p.stdout);
+      List<String> tests = new List<String>();
+      stdoutStream.onLine = () {
+        String line = stdoutStream.readLine();
+        while (line != null) {
+          tests.add(line);
+          line = stdoutStream.readLine();
+        }
+      };
+      p.onError = processErrorHandler;
+      p.onExit = (code) {
+        if (code < 0) {
+          print("Failed to list tests: $runnerPath --list");
+          replyTo.send("");
+        }
+        for (String test in tests) {
+          replyTo.send(test);
+        }
         replyTo.send("");
-      }
-      for (String test in tests) {
-        replyTo.send(test);
-      }
-      replyTo.send("");
-    };
-    port.close();
+      };
+      port.close();
+    });
+    processFuture.handleException((e) {
+      processErrorHandler(e);
+      return true;
+    });

[Søren Gjesse, 2012/10/12 07:47:22]

This code is now 7 lines longer...

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

I know. I removed onError on process. That means that killing a process can in
rare cases throw an exception. If it does, something funky is going on though,
so I think removing onError on process is the right thing to do.

   });
 }
 
 
 /**
  * A specialized [TestSuite] that runs tests written in C to unit test
  * the Dart virtual machine and its API.
  *
  * The tests are compiled into a monolithic executable by the build step.
  * The executable lists its tests when run with the --list command line flag.
@@ skipping 1364 matching lines @@
  * $noCrash tests are expected to be flaky but not crash
  * $pass tests are expected to pass
  * $failOk tests are expected to fail that we won't fix
  * $fail tests are expected to fail that we should fix
  * $crash tests are expected to crash that we should fix
  * $timeout tests are allowed to timeout
 """;
     print(report);
    }
 }