Make client tests return non-zero exit code on failure.

Make client tests return non-zero exit code on failure.

Committed: https://code.google.com/p/dart/source/detail?r=3203

[Bob Nystrom, 2012-01-11 01:57:43]

As far as I can tell, the client tests (i.e. any tests that are using
client/testing/unittest) aren't actually working correctly with test.py and
test.dart.

Both of those rely on a non-zero exit code from the called test script to
determine failure. Simple test scripts that just use Expect.blah() work because
the thrown exception unwinds the whole stack and causes dart to return non-zero.

Unittest doesn't do that: it catches all exceptions so that it can continue to
run the rest of the test suite. This means, as far as I can tell, test.py and
test.dart are reporting all client tests as succeeding even when they aren't.
Oops.

This fixes that.

[Siggi Cherem (dart-lang), 2012-01-11 02:15:02]

I have to take a closer look tomorrow, but for client tests test.py was parsing
the output to check if it said "PASS", and mark it would mark the test as
failing if it didn't. Has this changed?

[Bob Nystrom, 2012-01-11 18:30:44]

On 2012/01/11 02:15:02, sigmund wrote:
> I have to take a closer look tomorrow, but for client tests test.py was
parsing
> the output to check if it said "PASS", and mark it would mark the test as
> failing if it didn't. Has this changed?

Ah, I see what's going on here. There are a bunch of different pieces of code
that are involved:

1. The client/testing/unittest library.
2. test.py
3. test.dart
4. frog
5. node
6. The browser

These can be combined in fun ways like: compile dart->JS with frog, run on node,
but don't use unittest. etc.

The combination of: "use unittest" and "run on the browser" does work with both
test.py and test.dart because, as you say, it's looking at the browser output
for PASS/FAIL. The combinations that do not currently work, as far as I can
tell, are:

1. Use unittest and run on VM.
2. Use unittest and run on node.

Outside of dartdoc, I'm not sure if there are any other tests that use that
combination. The fact that the dartdoc tests don't work (they report false
passes) is how I found this bug.

This patch should fix those cases.

[Siggi Cherem (dart-lang), 2012-01-11 18:45:34]

lgtm

Ah, that makes sense now. Thanks for the explanation!