tests: add simplistic tests for Reader matches

It would be nice to run those tests against fake journal files
with the right content to actually test the matches. But those
tests are still useful because they test that the interface
works as expected.

Author: keszybz

systemd/test/test_journal.py

@@ -1,8 +1,11 @@
 import logging
-from systemd import journal
+import uuid
+from systemd import journal, id128
 
 import pytest
 
+TEST_MID = uuid.UUID('8441372f8dca4ca98694a6091fd8519f')
+
 def test_priorities():
     p = journal.JournalHandler.mapPriority
 
@@ -48,6 +51,35 @@ def test_reader_init_path(tmpdir):
     with pytest.raises(ValueError):
         journal.Reader(journal.LOCAL_ONLY, path=tmpdir.strpath)
 
+def test_reader_as_cm(tmpdir):
+    j = journal.Reader(path=tmpdir.strpath)
+    with j:
+        assert not j.closed
+    assert j.closed
+    # make sure that operations on the Reader fail
+    with pytest.raises(OSError):
+        next(j)
+
+def test_reader_messageid_match(tmpdir):
+    j = journal.Reader(path=tmpdir.strpath)
+    with j:
+        j.messageid_match(id128.SD_MESSAGE_JOURNAL_START)
+        j.messageid_match(id128.SD_MESSAGE_JOURNAL_STOP.hex)
+
+def test_reader_this_boot(tmpdir):
+    j = journal.Reader(path=tmpdir.strpath)
+    with j:
+        j.this_boot()
+        j.this_boot(TEST_MID)
+        j.this_boot(TEST_MID.hex)
+
+def test_reader_this_machine(tmpdir):
+    j = journal.Reader(path=tmpdir.strpath)
+    with j:
+        j.this_machine()
+        j.this_machine(TEST_MID)
+        j.this_machine(TEST_MID.hex)
+
 def test_reader_converters(tmpdir):
     converters = {'xxx' : lambda arg: 'yyy'}
     j = journal.Reader(path=tmpdir.strpath, converters=converters)