testing: annotate output text type

Provides a way to disambiguate output produced by (*testing.T).Error{,f}
and (*testing.T).Fatal{,f} from other test logging. This allows test
tooling such as CI systems to identify which part of the output is most
pertinent for constructing summaries of test failures.

This is achieved by adding an OutputType field to output events. The
output type for an error is "error" for the first line and
"error-continue" for subsequentlines. The output type for framing is
"frame". This is achieved by bracketing error output with ^O and ^N,
escaped with ^[.

Fixes golang/go#62728.

Change-Id: Ib09c18ed5f729e1ae6d335cd1ec7d818c71532e0
Reviewed-on: https://go-review.googlesource.com/c/go/+/601535
Reviewed-by: Michael Matloob <matloob@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>
Auto-Submit: Damien Neil <dneil@google.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/cmd/internal/test2json/testdata/timeout.json b/src/cmd/internal/test2json/testdata/timeout.json
index dc225262f7..325d811d0e 100644
--- a/src/cmd/internal/test2json/testdata/timeout.json
+++ b/src/cmd/internal/test2json/testdata/timeout.json
@@ -1,8 +1,8 @@
 {"Action":"start"}
 {"Action":"run","Test":"Test"}
-{"Action":"output","Test":"Test","Output":"=== RUN   Test\n"}
+{"Action":"output","Test":"Test","Output":"=== RUN   Test\n","OutputType":"frame"}
 {"Action":"output","Test":"Test","Output":"panic: test timed out after 1s\n"}
 {"Action":"output","Test":"Test","Output":"\n"}
-{"Action":"output","Output":"FAIL\tp\t1.111s\n"}
-{"Action":"output","Output":"FAIL\n"}
+{"Action":"output","Output":"FAIL\tp\t1.111s\n","OutputType":"frame"}
+{"Action":"output","Output":"FAIL\n","OutputType":"frame"}
 {"Action":"fail"}