Test: add ability to skip tests for unsupported file-systems

Add a new optional pytest CLI argument `--unsupported-fs` allowing to
specify file-systems which should be treated as unsupported in the
platform where running tests. Any test cases dependent on such
file-system support will be sipped.

This will allow to run unit tests and selectively skipping test cases
for unsupported file-systems.

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

test/conftest.py

@@ -0,0 +1,19 @@
+unsupported_filesystems = []
+"""Globally accessible list of filesystems that are unsupported on the system when running test cases"""
+
+
+def pytest_addoption(parser):
+    parser.addoption(
+        "--unsupported-fs",
+        action="append",
+        default=[],
+        metavar="FS",
+        help="List of filesystems to treat as unsupported on the system when running test cases." +
+             "Can be specified multiple times.",
+    )
+
+
+def pytest_configure(config):
+    # pylint: disable=global-statement
+    global unsupported_filesystems
+    unsupported_filesystems = config.getoption("--unsupported-fs")

test/run/test_assemblers.py

@@ -81,6 +81,8 @@ def read_partition_table(device):
 @pytest.mark.skipif(not test.TestBase.can_bind_mount(), reason="root-only")
 @pytest.mark.parametrize("fs_type", ["ext4", "xfs", "btrfs"])
 def test_rawfs(osbuild, fs_type):
+    if not test.TestBase.has_filesystem_support(fs_type):
+        pytest.skip(f"The {fs_type} was explicitly marked as unsupported on this platform.")
     options = {
         "filename": "image.raw",
         "root_fs_uuid": "016a1cda-5182-4ab3-bf97-426b00b74eb0",
@@ -150,17 +152,13 @@ def test_ostree(osbuild):
 @pytest.mark.skipif(not test.TestBase.have_tree_diff(), reason="tree-diff missing")
 @pytest.mark.skipif(not test.TestBase.have_test_data(), reason="no test-data access")
 @pytest.mark.skipif(not test.TestBase.can_bind_mount(), reason="root-only")
-@pytest.mark.parametrize(
-    "fmt,fs_type",
-    [("raw", "ext4"), ("raw", "xfs"), ("raw", "btrfs"),
-     ("raw.xz", "ext4"), ("raw.xz", "xfs"), ("raw.xz", "btrfs"),
-     ("qcow2", "ext4"), ("qcow2", "xfs"), ("qcow2", "btrfs"),
-     ("vmdk", "ext4"), ("vmdk", "xfs"), ("vmdk", "btrfs"),
-     ("vdi", "ext4"), ("vdi", "xfs"), ("vdi", "btrfs")]
-)
+@pytest.mark.parametrize("fmt,", ["raw", "raw.xz", "qcow2", "vmdk", "vdi"])
+@pytest.mark.parametrize("fs_type", ["ext4", "xfs", "btrfs"])
 def test_qemu(osbuild, fmt, fs_type):
     loctl = loop.LoopControl()
     with osbuild as osb:
+        if not test.TestBase.has_filesystem_support(fs_type):
+            pytest.skip(f"The {fs_type} was explicitly marked as unsupported on this platform.")
         options = {
             "format": fmt,
             "filename": f"image.{fmt}",

test/test.py

@@ -15,6 +15,8 @@ import osbuild.meta
 from osbuild.objectstore import ObjectStore
 from osbuild.util import linux
 
+from .conftest import unsupported_filesystems
+
 
 class TestBase(unittest.TestCase):
     """Base Class for Tests
@@ -263,6 +265,18 @@ class TestBase(unittest.TestCase):
         output = subprocess.check_output([os.path.join(checkout, "tools/tree-diff"), path1, path2])
         return json.loads(output)
 
+    @staticmethod
+    def has_filesystem_support(fs: str) -> bool:
+        """Check File-System Support
+
+        Check whether the current test-run has support for the given file-system.
+        The assumption is that any file-system is treated as supported, unless
+        explicitly marked as unsupported when executing pytest. This allows us
+        to skip tests for file-systems that are not supported on specific
+        platforms.
+        """
+        return fs not in unsupported_filesystems
+
 
 class OSBuild(contextlib.AbstractContextManager):
     """OSBuild Executor