Improve Vfs interface + refactoring.

tests/test_bsv/test_vfs.py

@@ -175,20 +175,50 @@ def test_metadata(fs: VirtualFileSystem):
     assert md.path == PurePosixPath("/test_file")
     assert md.permissions == file_permissions
     assert md.type == "file"
+    assert md.is_file
+    assert not md.is_dir
+    assert not md.is_symlink
+    assert not md.is_other
     assert md.modification_time == file_time
     assert md.byte_size == len(file_content)
     assert not md.is_hidden_files
     assert fs.metadata("/test_file") == md
+    assert fs.is_file("/test_file")
+    assert not fs.is_dir("/test_file")
+    assert not fs.is_symlink("/test_file")
+    assert not fs.is_other("/test_file")
 
     fs.set_permissions("/test_file", Permissions(0o644))
     assert fs.metadata("/test_file") != md
 
     fs.mkdir("/.test_dir")
-    assert fs.metadata("/.test_dir").type == "dir"
+    md = fs.metadata("/.test_dir")
+    assert md.type == "dir"
+    assert not md.is_file
+    assert md.is_dir
+    assert not md.is_symlink
+    assert not md.is_other
     assert fs.metadata("/.test_dir").is_hidden_files
+    assert not fs.is_file("/.test_dir")
+    assert fs.is_dir("/.test_dir")
+    assert not fs.is_symlink("/.test_dir")
+    assert not fs.is_other("/.test_dir")
 
     fs.make_link("/test_link", "/link_target")
-    assert fs.metadata("/test_link").type == "link"
+    md = fs.metadata("/test_link")
+    assert md.type == "symlink"
+    assert not md.is_file
+    assert not md.is_dir
+    assert md.is_symlink
+    assert not md.is_other
+    assert not fs.is_file("/test_link")
+    assert not fs.is_dir("/test_link")
+    assert fs.is_symlink("/test_link")
+    assert not fs.is_other("/test_link")
+
+    assert fs.metadata_or_none("/does_not_exist") is None
+    with pytest.raises(FsError):
+        fs.metadata("/does_not_exist")
 
 
 ########################################################################################
@@ -199,14 +229,14 @@ def test_iter_dir(fs: VirtualFileSystem):
     expected = [
         (PurePosixPath("/dir"), "dir"),
         (PurePosixPath("/file"), "file"),
-        (PurePosixPath("/link"), "link"),
+        (PurePosixPath("/link"), "symlink"),
     ]
     for path, file_type in expected:
         if file_type == "dir":
             fs.mkdir(path)
         elif file_type == "file":
             fs.write_bytes(path, b"")
-        elif file_type == "link":
+        elif file_type == "symlink":
             fs.make_link(path, "/foobar")
 
     items_metadata = sorted(fs.iter_dir("/"))