Use .zeek file suffix in unit tests

testing/btest/scripts/base/frameworks/logging/rotate.zeek

@@ -0,0 +1,32 @@
+#
+# @TEST-EXEC: bro -b -r ${TRACES}/rotation.trace %INPUT >bro.out 2>&1
+# @TEST-EXEC: grep "test" bro.out | sort >out
+# @TEST-EXEC: for i in `ls test.*.log | sort`; do printf '> %s\n' $i; cat $i; done >>out
+# @TEST-EXEC: btest-diff out
+
+module Test;
+
+export {
+	# Create a new ID for our log stream
+	redef enum Log::ID += { LOG };
+
+	# Define a record with all the columns the log file can have.
+	# (I'm using a subset of fields from ssh-ext for demonstration.)
+	type Log: record {
+		t: time;
+		id: conn_id; # Will be rolled out into individual columns.
+	} &log;
+}
+
+redef Log::default_rotation_interval = 1hr;
+redef Log::default_rotation_postprocessor_cmd = "echo";
+
+event bro_init()
+{
+	Log::create_stream(Test::LOG, [$columns=Log]);
+}
+
+event new_connection(c: connection)
+	{
+	Log::write(Test::LOG, [$t=network_time(), $id=c$id]);
+	}