Determine encoding of source files used for coverage

[jayudey-wf]

After upgrade past version 1.15.7 of the test package I was no longer able to collect code coverage.

After working with several of my teammates we tracked down that it was due to a non utf-8 character in one of the javascript sources that are being used by our browser tests.

It looks like this got introduced with the move away from the http package because it looks like it was handling that type of problem here.

RangeError (index): Invalid value: Not in inclusive range 0..335531: 335532
dart:core                                            List.[]=
package:coverage/src/chrome.dart 137:21              _offsetCoverage
package:coverage/src/chrome.dart 48:28               parseChromeCoverage
package:test/src/runner/browser/chrome.dart 111:20   Chrome.gatherCoverage
package:test_core/src/runner/runner_suite.dart 79:8  RunnerSuite.gatherCoverage
package:test_core/src/runner/coverage.dart 16:18     writeCoverage
package:test_core/src/runner/engine.dart 270:36      Engine.run.<fn>.<fn>

This is an unexpected error. Please file an issue at http://github.com/dart-lang/test
with the stack trace and instructions for reproducing the error.
Unhandled exception:
RangeError (index): Invalid value: Not in inclusive range 0..335531: 335532
#0      List._setIndexed (dart:core-patch/array.dart:118:64)
#1      List.[]= (dart:core-patch/array.dart:114:5)
#2      _offsetCoverage (package:coverage/src/chrome.dart:137:21)
#3      parseChromeCoverage (package:coverage/src/chrome.dart:48:28)
<asynchronous suspension>
#4      Chrome.gatherCoverage (package:test/src/runner/browser/chrome.dart:111:20)
<asynchronous suspension>
#5      RunnerSuite.gatherCoverage (package:test_core/src/runner/runner_suite.dart:79:8)
<asynchronous suspension>
#6      writeCoverage (package:test_core/src/runner/coverage.dart:16:18)
<asynchronous suspension>
#7      Engine.run.<anonymous closure>.<anonymous closure> (package:test_core/src/runner/engine.dart:270:36)
<asynchronous suspension>

[google-cla]

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For more information, open the CLA check for this pull request.

[kevmoo]

@jayudey-wf – need to figure out the CLA check. This looks great, BTW!

[jayudey-wf]

I signed the individual one, but I think Workiva has a corporate one as well

[natebosch]

Thanks for finding this!