tests: skip journal.stream tests on ENOENT error

When running in a chroot, doctests that called journal.stream would
fail with ENOENT. Move the tests to test_journal, where we can skip
tests properly (without uglyfying the documentation).

Fixes #32.

Author: keszybz

systemd/journal.py

@@ -456,8 +456,8 @@ def stream(identifier=None, priority=LOG_INFO, level_prefix=False):
     newline character is written.
 
     >>> from systemd import journal
-    >>> stream = journal.stream('myapp')
-    >>> res = stream.write('message...\n')
+    >>> stream = journal.stream('myapp')                       # doctest: +SKIP
+    >>> res = stream.write('message...\n')                     # doctest: +SKIP
 
     will produce the following message in the journal::
 
@@ -470,8 +470,8 @@ def stream(identifier=None, priority=LOG_INFO, level_prefix=False):
     This interface can be used conveniently with the print function:
 
     >>> from __future__ import print_function
-    >>> fileobj = journal.stream()
-    >>> print('message...', file=fileobj)                      # doctest: +SKIP
+    >>> stream = journal.stream()                              # doctest: +SKIP
+    >>> print('message...', file=stream)                       # doctest: +SKIP
 
     priority is the syslog priority, one of `LOG_EMERG`, `LOG_ALERT`,
     `LOG_CRIT`, `LOG_ERR`, `LOG_WARNING`, `LOG_NOTICE`, `LOG_INFO`, `LOG_DEBUG`.

systemd/test/test_journal.py

@@ -1,3 +1,4 @@
+from __future__ import print_function
 import contextlib
 import datetime
 import errno
@@ -13,11 +14,11 @@
 TEST_MID = uuid.UUID('8441372f8dca4ca98694a6091fd8519f')
 
 @contextlib.contextmanager
-def skip_enosys():
+def skip_oserror(code):
     try:
         yield
-    except OSError as e:
-        if e.errno == errno.ENOSYS:
+    except (OSError, IOError) as e:
+        if e.errno == code:
             pytest.skip()
         raise
 
@@ -96,7 +97,7 @@ def test_reader_init_path_nondirectory_fd():
 def test_reader_init_path_fd(tmpdir):
     fd = os.open(tmpdir.strpath, os.O_RDONLY)
 
-    with skip_enosys():
+    with skip_oserror(errno.ENOSYS):
         j1 = journal.Reader(path=fd)
     assert list(j1) == []
 
@@ -139,30 +140,30 @@ def test_reader_this_machine(tmpdir):
 def test_reader_query_unique(tmpdir):
     j = journal.Reader(path=tmpdir.strpath)
     with j:
-        with skip_enosys():
+        with skip_oserror(errno.ENOSYS):
             ans = j.query_unique('FOOBAR')
     assert isinstance(ans, set)
     assert ans == set()
 
 def test_reader_enumerate_fields(tmpdir):
     j = journal.Reader(path=tmpdir.strpath)
     with j:
-        with skip_enosys():
+        with skip_oserror(errno.ENOSYS):
             ans = j.enumerate_fields()
     assert isinstance(ans, set)
     assert ans == set()
 
 def test_reader_has_runtime_files(tmpdir):
     j = journal.Reader(path=tmpdir.strpath)
     with j:
-        with skip_enosys():
+        with skip_oserror(errno.ENOSYS):
             ans = j.has_runtime_files()
     assert ans == False
 
 def test_reader_has_persistent_files(tmpdir):
     j = journal.Reader(path=tmpdir.strpath)
     with j:
-        with skip_enosys():
+        with skip_oserror(errno.ENOSYS):
             ans = j.has_runtime_files()
     assert ans == False
 
@@ -200,3 +201,13 @@ def test_seek_realtime(tmpdir):
 
     long_ago = datetime.datetime(1970, 5, 4)
     j.seek_realtime(long_ago)
+
+def test_journal_stream():
+    # This will fail when running in a bare chroot without /run/systemd/journal/stdout
+    with skip_oserror(errno.ENOENT):
+        stream = journal.stream('test_journal.py')
+
+    res = stream.write('message...\n')
+    assert res in (11, None) # Python2 returns None
+
+    print('printed message...', file=stream)