chore: add type annotations to cloudinit.distros.parsers.hosts

cloudinit/distros/parsers/hosts.py

@@ -5,6 +5,7 @@
 # This file is part of cloud-init. See LICENSE file for license information.
 
 from io import StringIO
+from typing import Any, List, Tuple
 
 from cloudinit.distros.parsers import chop_comment
 
@@ -13,69 +14,71 @@
 # or https://linux.die.net/man/5/hosts
 # or https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-configfiles.html # noqa
 class HostsConf:
-    def __init__(self, text):
+    def __init__(self, text: str) -> None:
         self._text = text
-        self._contents = None
+        self._contents: List[Tuple[str, List[Any]]] = []
 
-    def parse(self):
-        if self._contents is None:
+    def parse(self) -> None:
+        if not self._contents:
             self._contents = self._parse(self._text)
 
-    def get_entry(self, ip):
+    def get_entry(self, ip: str) -> List[List[str]]:
         self.parse()
-        options = []
+        options: List[List[str]] = []
         for line_type, components in self._contents:
             if line_type == "option":
-                (pieces, _tail) = components
+                pieces, _tail = components
                 if len(pieces) and pieces[0] == ip:
                     options.append(pieces[1:])
         return options
 
-    def del_entries(self, ip):
+    def del_entries(self, ip: str) -> None:
         self.parse()
-        n_entries = []
+        n_entries: List[Tuple[str, List[Any]]] = []
         for line_type, components in self._contents:
             if line_type != "option":
                 n_entries.append((line_type, components))
                 continue
             else:
-                (pieces, _tail) = components
+                pieces, _tail = components
                 if len(pieces) and pieces[0] == ip:
                     pass
                 elif len(pieces):
                     n_entries.append((line_type, list(components)))
         self._contents = n_entries
 
-    def add_entry(self, ip, canonical_hostname, *aliases):
+    def add_entry(
+        self, ip: str, canonical_hostname: str, *aliases: str
+    ) -> None:
         self.parse()
         self._contents.append(
-            ("option", ([ip, canonical_hostname] + list(aliases), ""))
+            ("option", [[ip, canonical_hostname] + list(aliases), ""])
         )
 
-    def _parse(self, contents):
-        entries = []
+    def _parse(self, contents: str) -> List[Tuple[str, List[Any]]]:
+        entries: List[Tuple[str, List[Any]]] = []
         for line in contents.splitlines():
             if not len(line.strip()):
                 entries.append(("blank", [line]))
                 continue
-            (head, tail) = chop_comment(line.strip(), "#")
+            head, tail = chop_comment(line.strip(), "#")
             if not len(head):
                 entries.append(("all_comment", [line]))
                 continue
             entries.append(("option", [head.split(None), tail]))
         return entries
 
-    def __str__(self):
+    def __str__(self) -> str:
         self.parse()
         contents = StringIO()
         for line_type, components in self._contents:
             if line_type == "blank":
-                contents.write("%s\n" % (components[0]))
+                contents.write("%s\n" % components[0])
             elif line_type == "all_comment":
-                contents.write("%s\n" % (components[0]))
+                contents.write("%s\n" % components[0])
             elif line_type == "option":
-                (pieces, tail) = components
-                pieces = [str(p) for p in pieces]
-                pieces = "\t".join(pieces)
-                contents.write("%s%s\n" % (pieces, tail))
+                raw_pieces, tail = components
+                str_pieces = [str(p) for p in raw_pieces]
+                joined = "\t".join(str_pieces)
+                contents.write(f"{joined}{tail}\n")
         return contents.getvalue()

pyproject.toml

@@ -52,7 +52,6 @@ module = [
     "cloudinit.distros.bsd",
     "cloudinit.distros.opensuse",
     "cloudinit.distros.parsers.hostname",
-    "cloudinit.distros.parsers.hosts",
     "cloudinit.distros.parsers.resolv_conf",
     "cloudinit.distros.ug_util",
     "cloudinit.helpers",
@@ -114,7 +113,6 @@ module = [
     "tests.unittests.config.test_cc_zypper_add_repo",
     "tests.unittests.config.test_modules",
     "tests.unittests.config.test_schema",
-    "tests.unittests.distros.test_hosts",
     "tests.unittests.distros.test_ifconfig",
     "tests.unittests.distros.test_netbsd",
     "tests.unittests.distros.test_netconfig",

tests/unittests/distros/test_hosts.py

@@ -21,8 +21,8 @@ def test_parse(self):
             ["foo.mydomain.org", "foo"],
             ["bar.mydomain.org", "bar"],
         ]
-        eh = str(eh)
-        assert eh.startswith("# Example")
+        eh_str = str(eh)
+        assert eh_str.startswith("# Example")
 
     def test_add(self):
         eh = hosts.HostsConf(BASE_ETC)