Add empty syntax type for suppressing output

1 files changed, 27 insertions, 0 deletions

diff --git a/test/test_empty.py b/test/test_empty.py
new file mode 100755
index 00000000..a7978e6c
--- /dev/null
+++ b/test/test_empty.py
@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+
+"""Test writing empty output."""
+
+import argparse
+import sys
+import shlex
+import subprocess
+import tempfile
+
+parser = argparse.ArgumentParser(description=__doc__)
+
+parser.add_argument("--serdi", default="./serdi", help="path to serdi")
+parser.add_argument("--wrapper", default="", help="executable wrapper")
+parser.add_argument("input", help="valid input file")
+
+args = parser.parse_args(sys.argv[1:])
+command = shlex.split(args.wrapper) + [args.serdi, "-o", "empty", args.input]
+
+with tempfile.TemporaryFile() as out:
+
+    proc = subprocess.run(command, check=False, stdout=out)
+
+    out.seek(0, 2)  # Seek to end
+
+    assert proc.returncode == 0
+    assert out.tell() == 0