Make 'useXConfiguration' check for an existing configuration. This is so that it

Make 'useXConfiguration' check for an existing configuration. This is so that it
is possible to compose tests:
testa() => useVmConfig();
testb() => useVmConfig(); testa();

This is now important because we moved some of the configuration state to
onInit, so by the time the second configure is called, the initialization might
have already been done.

An alternative would be to only allow to call configure once. Thoughts?

Committed: https://code.google.com/p/dart/source/detail?r=16981

[Siggi Cherem (dart-lang), 2013-01-11 18:18:26]

... and another option to consider is adding a boolean argument to configure so
you decide whether or not to override an existing configuration:

configure(Configuration c, {replace: false)) {
  if (_config == null || !_initialized || replace) {
    ...
  }
}

[gram, 2013-01-11 18:48:49]

lgtm

https://codereview.chromium.org/11862002/diff/1/pkg/unittest/lib/compact_vm_c...
File pkg/unittest/lib/compact_vm_config.dart (left):

https://codereview.chromium.org/11862002/diff/1/pkg/unittest/lib/compact_vm_c...
pkg/unittest/lib/compact_vm_config.dart:169: void notifyController(String msg)
{}
I assume this is okay, although it is not related to the rest of the CL.

[Siggi Cherem (dart-lang), 2013-01-11 19:03:13]

thanks!

https://codereview.chromium.org/11862002/diff/1/pkg/unittest/lib/compact_vm_c...
File pkg/unittest/lib/compact_vm_config.dart (left):

https://codereview.chromium.org/11862002/diff/1/pkg/unittest/lib/compact_vm_c...
pkg/unittest/lib/compact_vm_config.dart:169: void notifyController(String msg)
{}
On 2013/01/11 18:48:49, gram wrote:
> I assume this is okay, although it is not related to the rest of the CL.

yeah - in a previous CL I made this a subclass of vm_config, which already has a
method just like it.