testing: document exit codes

Fixes #25989

Change-Id: I2e2a2a17854034ff68e69b8973018b1b2e7d59f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/660076
Reviewed-by: Thanyalak Detkhong (Palm’my) <pmy4416@gmail.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/testing/testing.go b/src/testing/testing.go
index 5b0a33f28d4db2c6083651cf188e753534950374..b03e6fdeda6d62c080cb9b1567f7ec778878a0c0 100644 (file)
--- a/src/testing/testing.go
+++ b/src/testing/testing.go
@@ -2043,6 +2043,9 @@ var testingTesting bool
 var realStderr *os.File
 
 // Run runs the tests. It returns an exit code to pass to os.Exit.
+// The exit code is zero when all tests pass, and non-zero for any kind
+// of failure. For machine readable test results, parse the output of
+// 'go test -json'.
 func (m *M) Run() (code int) {
        defer func() {
                code = m.exitCode