The Discover tests step runs under set -euo pipefail, so when every
Test function in a file is filtered out by the exclude regex (as with
vnetperf_test.go, whose TestVnetPerf* tests need special invocation),
the final grep -vE produces no output and exits 1, failing the whole
step. Tolerate empty results from both greps so such files simply
contribute no matrix entries. Same for a hypothetical future test
file containing only helpers and no Test functions.
Updates tailscale/corp#44805
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: If20c9a1de37e97b1553bd7d5559e2b876a45c19b
Brad FitzpatrickandBrad Fitzpatrick
3c800dcd71