Enable shards in runtime test runner.

Fixed an issue with the runtime test runner which enables us to run tests in
shards. We had to touch the status file as indicated by an env var.

PiperOrigin-RevId: 320236205

1 files changed, 15 insertions, 0 deletions

diff --git a/pkg/test/testutil/testutil.go b/pkg/test/testutil/testutil.go
index f21d6769a..64c292698 100644
--- a/pkg/test/testutil/testutil.go
+++ b/pkg/test/testutil/testutil.go
@@ -482,6 +482,21 @@ func IsStatic(filename string) (bool, error) {
 	return true, nil
 }
 
+// TouchShardStatusFile indicates to Bazel that the test runner supports
+// sharding by creating or updating the last modified date of the file
+// specified by TEST_SHARD_STATUS_FILE.
+//
+// See https://docs.bazel.build/versions/master/test-encyclopedia.html#role-of-the-test-runner.
+func TouchShardStatusFile() error {
+	if statusFile := os.Getenv("TEST_SHARD_STATUS_FILE"); statusFile != "" {
+		cmd := exec.Command("touch", statusFile)
+		if b, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("touch %q failed:\n output: %s\n error: %s", statusFile, string(b), err.Error())
+		}
+	}
+	return nil
+}
+
 // TestIndicesForShard returns indices for this test shard based on the
 // TEST_SHARD_INDEX and TEST_TOTAL_SHARDS environment vars.
 //