Customize line ending in report

[fpawel]

HI!
in formatter/formatter.go 107 we have hardcoded lines separtor Contents: strings.Join(test.Output, "\n"),
In fact, this breaks the display of the stack trace of the failed tests in Jenkins.
F.e. this

<testcase classname="zfs" name="TestZpoolTestSuite" time="0.000">
			<failure message="Failed" type=""></failure>
		</testcase>
		<testcase classname="zfs" name="TestZpoolTestSuite/TestGetFreeing_err" time="0.000">
			<failure message="Failed" type="">    suite.go:63: test panicked: failed&#xA;        goroutine 76 [running]:&#xA;        runtime/debug.Stack(0xc00006ab48, 0xd30260, 0x10707b0)&#xA;        github.com/stretchr/testify/suite.failOnPanic(0xc00012e900)&#xA;        panic(0xd30260, 0x10707b0)&#xA;        szs-op/zfs.(*ZpoolTestSuite).SetupTest(0xc000767e00)&#xA;        github.com/stretchr/testify/suite.Run.func1(0xc00012e900)&#xA;        testing.tRunner(0xc00012e900, 0xc0005a9290)&#xA;        created by testing.(*T).Run</failure>
		</testcase>
		<testcase classname="zfs" name="TestZpoolTestSuite/TestGetFreeing_noOutput" time="0.000">
			<failure message="Failed" type="">    suite.go:63: test panicked: failed&#xA;        goroutine 77 [running]:&#xA;        runtime/debug.Stack(0xc00006ab48, 0xd30260, 0x10707b0)&#xA;        github.com/stretchr/testify/suite.failOnPanic(0xc00012ea80)&#xA;        panic(0xd30260, 0x10707b0)&#xA;        szs-op/zfs.(*ZpoolTestSuite).SetupTest(0xc000767e00)&#xA;        github.com/stretchr/testify/suite.Run.func1(0xc00012ea80)&#xA;        testing.tRunner(0xc00012ea80, 0xc0005a9320)&#xA;        created by testing.(*T).Run</failure>
		</testcase>
		<testcase classname="zfs" name="TestZpoolTestSuite/TestGetFreeing_value" time="0.000">
			<failure message="Failed" type="">    suite.go:63: test panicked: failed&#xA;        goroutine 78 [running]:&#xA;        runtime/debug.Stack(0xc00006ab48, 0xd30260, 0x10707b0)&#xA;        github.com/stretchr/testify/suite.failOnPanic(0xc00012ec00)&#xA;        panic(0xd30260, 0x10707b0)&#xA;        szs-op/zfs.(*ZpoolTestSuite).SetupTest(0xc000767e00)&#xA;        github.com/stretchr/testify/suite.Run.func1(0xc00012ec00)&#xA;        testing.tRunner(0xc00012ec00, 0xc0005a93b0)&#xA;        created by testing.(*T).Run</failure>
		</testcase>
		<testcase classname="zfs" name="TestZpoolTestSuite/TestGetFreeing_zero" time="0.000">
			<failure message="Failed" type="">    suite.go:63: test panicked: failed&#xA;        goroutine 79 [running]:&#xA;        runtime/debug.Stack(0xc00006ab48, 0xd30260, 0x10707b0)&#xA;        github.com/stretchr/testify/suite.failOnPanic(0xc00012ed80)&#xA;        panic(0xd30260, 0x10707b0)&#xA;        szs-op/zfs.(*ZpoolTestSuite).SetupTest(0xc000767e00)&#xA;        github.com/stretchr/testify/suite.Run.func1(0xc00012ed80)&#xA;        testing.tRunner(0xc00012ed80, 0xc0005a9440)&#xA;        created by testing.(*T).Run</failure>
		</testcase>

is shown like this

I replaced word "
" with word "
" in the report, as a result I got the expected picture

I see the solution to the problem in customizing the word added to the end of the line through the command line parameters. If you approve, I will offer an appropriate pull request

[jstemmer]

Are you running Jenkins on a Windows server, or is this something specific to Jenkins itself?