add --log functionality

[aerickson]

a continuation of work done in lzap@9f6cc69

Please let me know if you'd like this squashed.

Thanks,
Andy

[aerickson]

@sstephenson and @lzap, any thoughts?

Thanks,
Andy

[aerickson]

An example of the output is below.

test.bats

#!/usr/bin/env bash

@test "Test exit 128" {
    run bash -c "echo 'fat'"
    run bash -c "echo ''"
    run bash -c "echo ''"
    run bash -c "echo 'cat'"
    # [ "$status" -eq 128 ]
}

output in /tmp/bats.log from running bats --log test.bats

[74562] starting 'Test exit 128'
[74562] <<< begin output >>>
fat
cat
[74562] <<< end output >>>
[74562] ok 'Test exit 128'

---

/tmp/bats.log output from running ./bin/bats ./test/fixtures/bats/failing.bats --log

[20035] starting 'a failing test'
[20035] <<< begin output >>>
[20035] <<< end output >>>
# (in test file test/fixtures/bats/failing.bats, line 4)
#   `eval "( exit ${STATUS:-1} )"' failed
[20035] not ok 'a failing test'

[lzap]

Hmm looks good, if there is chance of having an extra option(s) to configure bats to output to STDOUT, could be helpful too.

[kakawait]

really helpful feature! Can't imagine develop bash testing without (STDOUT)

[harschware]

Our team uses BATS, and has been struggling with STDOUT being gobbled by BATS. It seems to me the most useful solution is to have BATS have an option to write TAP output to a file, instead of STDOUT, and just let STDOUT alone so anything written to STDOUT by any process or sub-process proceeds as normal.

[csakoda]

Any chance this will be merged?