MountFlags: support conversion to and from a textual representation

The textual representation matches util-linux. Not all flag values can
be represented textually.

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/test_simple.py b/tests/test_simple.py
index cb654aa..960bf02 100644
--- a/tests/test_simple.py
+++ b/tests/test_simple.py
@@ -12,6 +12,24 @@ import pytest
 import linuxnamespaces
 
 
+class MountFlagsTest(unittest.TestCase):
+    def test_tostrfromstr(self) -> None:
+        for bit1 in range(32):
+            for bit2 in range(bit1, 32):
+                flag = (
+                    linuxnamespaces.MountFlags(1 << bit1)
+                    | linuxnamespaces.MountFlags(1 << bit2)
+                )
+                try:
+                    text = flag.tostr()
+                except ValueError:
+                    continue
+                self.assertEqual(
+                    linuxnamespaces.MountFlags.fromstr(text),
+                    flag
+                )
+
+
 class IDAllocationTest(unittest.TestCase):
     def test_idalloc(self) -> None:
         alloc = linuxnamespaces.IDAllocation()