logging: Use /dev/null as test filter
By using this filter for sink tests, we avoid Stackdriver trying to
export any logs during an integration test run.
Change-Id: I80bd37200e913975560c299bb8eb73186db26fdc
Reviewed-on: https://code-review.googlesource.com/c/35450
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jean de Klerk <deklerk@google.com>
diff --git a/logging/logadmin/sinks_test.go b/logging/logadmin/sinks_test.go
index aa59d61..f88c038 100644
--- a/logging/logadmin/sinks_test.go
+++ b/logging/logadmin/sinks_test.go
@@ -34,7 +34,8 @@
var sinkIDs = uid.NewSpace("GO-CLIENT-TEST-SINK", nil)
-const testFilter = ""
+// testFilter matches no logs to avoid exporting anything into the sinks.
+const testFilter = `textPayload="/dev/null"`
var testSinkDestination string
