improve linux test coverage

3 files changed, 26 insertions, 7 deletions

diff --git a/psutil/_pslinux.py b/psutil/_pslinux.py
index a0a4d350..3f1ff721 100644
--- a/psutil/_pslinux.py
+++ b/psutil/_pslinux.py
@@ -329,7 +329,7 @@ def boot_time():
                 ret = float(line.strip().split()[1])
                 BOOT_TIME = ret
                 return ret
-        raise RuntimeError("line 'btime' not found")
+        raise RuntimeError("line 'btime' not found in /proc/stat")
 
 
 # --- processes
@@ -1148,27 +1148,30 @@ class Process(object):
 
     @wrap_exceptions
     def ppid(self):
-        with open("/proc/%s/status" % self.pid, 'rb') as f:
+        fpath = "/proc/%s/status" % self.pid
+        with open(fpath, 'rb') as f:
             for line in f:
                 if line.startswith(b"PPid:"):
                     # PPid: nnnn
                     return int(line.split()[1])
-            raise NotImplementedError("line not found")
+            raise NotImplementedError("line 'PPid' not found in %s" % fpath)
 
     @wrap_exceptions
     def uids(self):
-        with open("/proc/%s/status" % self.pid, 'rb') as f:
+        fpath = "/proc/%s/status" % self.pid
+        with open(fpath, 'rb') as f:
             for line in f:
                 if line.startswith(b'Uid:'):
                     _, real, effective, saved, fs = line.split()
                     return _common.puids(int(real), int(effective), int(saved))
-            raise NotImplementedError("line not found")
+            raise NotImplementedError("line 'Uid' not found in %s" % fpath)
 
     @wrap_exceptions
     def gids(self):
-        with open("/proc/%s/status" % self.pid, 'rb') as f:
+        fpath = "/proc/%s/status" % self.pid
+        with open(fpath, 'rb') as f:
             for line in f:
                 if line.startswith(b'Gid:'):
                     _, real, effective, saved, fs = line.split()
                     return _common.pgids(int(real), int(effective), int(saved))
-            raise NotImplementedError("line not found")
+            raise NotImplementedError("line 'Gid' not found in %s" % fpath)
diff --git a/test/_linux.py b/test/_linux.py
index 5d7f0521..57e37bd2 100644
--- a/test/_linux.py
+++ b/test/_linux.py
@@ -321,6 +321,20 @@ class LinuxSpecificTestCase(unittest.TestCase):
                 psutil._pslinux.Process(os.getpid()).gids)
             assert m.called
 
+    def test_proc_io_counters_mocked(self):
+        with mock.patch('psutil._pslinux.open', create=True) as m:
+            self.assertRaises(
+                NotImplementedError,
+                psutil._pslinux.Process(os.getpid()).io_counters)
+            assert m.called
+
+    def test_boot_time_mocked(self):
+        with mock.patch('psutil._pslinux.open', create=True) as m:
+            self.assertRaises(
+                RuntimeError,
+                psutil._pslinux.boot_time)
+            assert m.called
+
     # --- tests for specific kernel versions
 
     @unittest.skipUnless(
diff --git a/test/test_psutil.py b/test/test_psutil.py
index b93cd863..842fff78 100644
--- a/test/test_psutil.py
+++ b/test/test_psutil.py
@@ -675,6 +675,8 @@ class TestSystemAPIs(unittest.TestCase):
         self.assertFalse(psutil.pid_exists(sproc.pid))
         self.assertFalse(psutil.pid_exists(-1))
         self.assertEqual(psutil.pid_exists(0), 0 in psutil.pids())
+        # pid 0
+        psutil.pid_exists(0) == 0 in psutil.pids()
 
     def test_pid_exists_2(self):
         reap_children()