tests: add first test

This is based on the code in #4
by Jacek Konieczny <j.konieczny@eggsoft.pl>.

systemd/test/test_daemon.py

@@ -0,0 +1,64 @@
+import sys
+import os
+import posix
+from systemd.daemon import _is_fifo, is_fifo
+
+import pytest
+
+def test__is_fifo(tmpdir):
+    path = tmpdir.join('test.fifo').strpath
+    posix.mkfifo(path)
+    fd = os.open(path, os.O_RDONLY|os.O_NONBLOCK)
+
+    assert _is_fifo(fd, None)
+    assert _is_fifo(fd, path)
+
+def test__is_fifo_file(tmpdir):
+    file = tmpdir.join('test.fifo')
+    file.write('boo')
+    path = file.strpath
+    fd = os.open(path, os.O_RDONLY|os.O_NONBLOCK)
+
+    assert not _is_fifo(fd, None)
+    assert not _is_fifo(fd, path)
+
+def test__is_fifo_bad_fd(tmpdir):
+    path = tmpdir.join('test.fifo').strpath
+
+    with pytest.raises(OSError):
+        assert not _is_fifo(-1, None)
+
+    with pytest.raises(OSError):
+        assert not _is_fifo(-1, path)
+
+def test_is_fifo(tmpdir):
+    path = tmpdir.join('test.fifo').strpath
+    posix.mkfifo(path)
+    fd = os.open(path, os.O_RDONLY|os.O_NONBLOCK)
+    file = os.fdopen(fd, 'r')
+
+    assert is_fifo(file, None)
+    assert is_fifo(file, path)
+    assert is_fifo(fd, None)
+    assert is_fifo(fd, path)
+
+def test_is_fifo_file(tmpdir):
+    file = tmpdir.join('test.fifo')
+    file.write('boo')
+    path = file.strpath
+    fd = os.open(path, os.O_RDONLY|os.O_NONBLOCK)
+    file = os.fdopen(fd, 'r')
+
+    assert not is_fifo(file, None)
+    assert not is_fifo(file, path)
+    assert not is_fifo(fd, None)
+    assert not is_fifo(fd, path)
+
+def test_is_fifo_bad_fd(tmpdir):
+    path = tmpdir.join('test.fifo').strpath
+
+    with pytest.raises(OSError):
+        assert not is_fifo(-1, None)
+
+    with pytest.raises(OSError):
+        assert not is_fifo(-1, path)