fix: harden encoding of output text

[aiche]

After upgrading from v0.3.0 to v0.4.1 we experienced issues when using rspec_junit_formatter together with serverspec. Text that was originally encoded in UTF-8 was treated as ASCII and when trying to be encoded in UTF-8 as part of the escape method gave the following error

Traceback (most recent call last):
	23: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/exe/rspec:4:in `<main>'
	22: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/runner.rb:45:in `invoke'
	21: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/runner.rb:71:in `run'
	20: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/runner.rb:87:in `run'
	19: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/runner.rb:112:in `run_specs'
	18: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/reporter.rb:81:in `report'
	17: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/reporter.rb:171:in `finish'
	16: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/reporter.rb:191:in `close_after'
	15: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/reporter.rb:182:in `block in finish'
	14: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/reporter.rb:205:in `notify'
	13: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/reporter.rb:205:in `each'
	12: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec-core-3.7.1/lib/rspec/core/reporter.rb:206:in `block in notify'
	11: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter/rspec3.rb:19:in `dump_summary'
	10: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter/rspec3.rb:113:in `without_color'
	 9: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter/rspec3.rb:100:in `swap_rspec_configuration'
	 8: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter/rspec3.rb:19:in `block in dump_summary'
	 7: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter.rb:32:in `xml_dump'
	 6: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter.rb:37:in `xml_dump_examples'
	 5: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter.rb:37:in `each'
	 4: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter.rb:44:in `block in xml_dump_examples'
	 3: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter.rb:74:in `xml_dump_example'
	 2: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter.rb:83:in `xml_dump_output'
	 1: from /usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter.rb:167:in `escape'
/usr/local/lib/ruby/gems/2.5.0/gems/rspec_junit_formatter-0.4.1/lib/rspec_junit_formatter.rb:167:in `encode': "\xE2" from ASCII-8BIT to UTF-8 (Encoding::UndefinedConversionError)
rake aborted!
NoMethodError: undefined method `match' for nil:NilClass
[..]
(See full trace by running task with --trace)

After a bit of research I stumbled on the following issue JoshCheek/seeing_is_believing#46. While the root cause is different, the #force_encoding solved my issue, since I so far couldn't determine the exact point in my setup were the encoding was messed up.

I'm not 100% sure if this should be included here, but it solved our issue so I wanted to at least share it.

[sj26]

I'm not super keen on forcing one encoding over the top of another when we have no knowledge or control over the source string — it's not ours. This sounds like a problem well above rspec_junit_formatter and should probably be fixed at the source.

Can you provide an example spec which fails in rspec_junit_formatter and succeeds after this change?

[aiche]

I will try to come up with a minimal example to reproduce the issue. Hope I will find some time over the weekend.

[aiche]

I could finally identify the part of my setup that messes with the string encoding (for anyone interested net/ssh fails to properly encode unicode messages that are sent via stdout from a remote machine). I will close this PR again.

[sj26]

Glad you got it sorted out, @aiche! 🙌