Ömer Sinan Ağacan
293b6379b8
`testConfigurations` expects at least one configuration, so avoid
calling it when there are no configurations.
This fixes the unhandled exception with `test_runner.dart --help`:
```
No build targets found.
Unhandled exception:
RangeError (index): Invalid value: Valid value range is empty: 0
<asynchronous suspension>
```
With this commit, `--help` just prints "No build targets found" and
exits with 0.
This crash was previously fixed in
02a0396f74.
Change-Id: Id82c83f66871c4e811a7502f1e831a0592db2065
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/257580
Reviewed-by: Bob Nystrom <rnystrom@google.com>
Commit-Queue: Ömer Ağacan <omersa@google.com>