Ensure that symlink-arguments are resolved (ansible#2476)

- Fixes bug where a giving a symlinked directory as argument would
  fail to lint the entire role, basically because the linter failed
  to resolve the link before processing all lintables within it.
- Ensure we resolve symlink in Lintable constructor
- Add normalization function that returns a Path

.github/workflows/tox.yml

@@ -166,7 +166,7 @@ jobs:
       WSLENV: FORCE_COLOR:PYTEST_REQPASS:TOXENV:TOX_PARALLEL_NO_SPINNER
       # Number of expected test passes, safety measure for accidental skip of
       # tests. Update value if you add/remove tests.
-      PYTEST_REQPASS: 698
+      PYTEST_REQPASS: 702
 
     steps:
       - name: Activate WSL1

.pylintrc

@@ -24,3 +24,7 @@ disable =
 [TYPECHECK]
 # pylint is unable to detect Namespace attributes and will throw a E1101
 generated-members=options.*
+
+[SUMMARY]
+# We don't need the score spamming console, as we either pass or fail
+score=n

src/ansiblelint/cli.py

@@ -529,7 +529,8 @@ def get_config(arguments: list[str]) -> Namespace:
 
     if options.project_dir == ".":
         project_dir = guess_project_dir(options.config_file)
-        options.project_dir = normpath(project_dir)
+        options.project_dir = os.path.expanduser(normpath(project_dir))
+
     if not options.project_dir or not os.path.exists(options.project_dir):
         raise RuntimeError(
             f"Failed to determine a valid project_dir: {options.project_dir}"

src/ansiblelint/file_utils.py

@@ -59,12 +59,51 @@ def normpath(path: str | BasePathLike) -> str:
     # conversion to string in order to allow receiving non string objects
     relpath = os.path.relpath(str(path))
     path_absolute = os.path.abspath(str(path))
+    if path_absolute.startswith(os.getcwd()):
+        return relpath
+    if path_absolute.startswith(os.path.expanduser("~")):
+        return path_absolute.replace(os.path.expanduser("~"), "~")
     # we avoid returning relative paths that end-up at root level
     if path_absolute in relpath:
         return path_absolute
     return relpath
 
 
+# That is needed for compatibility with py38, later was added to Path class
+def is_relative_to(path: Path, *other: Any) -> bool:
+    """Return True if the path is relative to another path or False."""
+    try:
+        path.resolve().absolute().relative_to(*other)
+        return True
+    except ValueError:
+        return False
+
+
+def normpath_path(path: str | BasePathLike) -> Path:
+    """Normalize a path in order to provide a more consistent output.
+
+    - Any symlinks are resolved.
+    - Any paths outside the CWD are resolved to their absolute path.
+    - Any absolute path within current user home directory is compressed to
+      make use of '~', so it is easier to read and more portable.
+    """
+    if not isinstance(path, Path):
+        path = Path(path)
+
+    is_relative = is_relative_to(path, path.cwd())
+    path = path.resolve()
+    if is_relative:
+        path = path.relative_to(path.cwd())
+
+    # Compress any absolute path within current user home directory
+    if path.is_absolute():
+        home = Path.home()
+        if is_relative_to(path, home):
+            path = Path("~") / path.relative_to(home)
+
+    return path
+
+
 @contextmanager
 def cwd(path: str | BasePathLike) -> Iterator[None]:
     """Context manager for temporary changing current working directory."""
@@ -133,6 +172,8 @@ class Lintable:
 
     Providing file content when creating the object allow creation of in-memory
     instances that do not need files to be present on disk.
+
+    When symlinks are given, they will always be resolved to their target.
     """
 
     def __init__(
@@ -142,20 +183,23 @@ def __init__(
         kind: FileType | None = None,
     ):
         """Create a Lintable instance."""
-        # Filename is effective file on disk, for stdin is a namedtempfile
-        self.filename: str = str(name)
         self.dir: str = ""
         self.kind: FileType | None = None
         self.stop_processing = False  # Set to stop other rules from running
         self._data: Any = None
         self.line_skips: dict[int, set[str]] = defaultdict(set)
 
         if isinstance(name, str):
-            self.name = normpath(name)
-            self.path = Path(self.name)
-        else:
-            self.name = str(name)
-            self.path = name
+            name = Path(name)
+        is_relative = is_relative_to(name, str(name.cwd()))
+        name = name.resolve()
+        if is_relative:
+            name = name.relative_to(name.cwd())
+        name = normpath_path(name)
+        self.path = name
+        # Filename is effective file on disk, for stdin is a namedtempfile
+        self.name = self.filename = str(name)
+
         self._content = self._original_content = content
         self.updated = False
 
@@ -312,7 +356,11 @@ def data(self) -> Any:
 
 # pylint: disable=redefined-outer-name
 def discover_lintables(options: Namespace) -> dict[str, Any]:
-    """Find all files that we know how to lint."""
+    """Find all files that we know how to lint.
+
+    Return format is normalized, relative for stuff below cwd, ~/ for content
+    under current user and absolute for everything else.
+    """
     # git is preferred as it also considers .gitignore
     git_command_present = [
         "git",

test/test_file_utils.py

@@ -21,6 +21,7 @@
     expand_paths_vars,
     guess_project_dir,
     normpath,
+    normpath_path,
 )
 
 from .conftest import cwd
@@ -200,7 +201,7 @@ def test_default_kinds(monkeypatch: MonkeyPatch, path: str, kind: FileType) -> N
 
     # pylint: disable=unused-argument
     def mockreturn(options: Namespace) -> dict[str, Any]:
-        return {path: kind}
+        return {normpath(path): kind}
 
     # assert Lintable is able to determine file type
     lintable_detected = Lintable(path)
@@ -411,3 +412,19 @@ def test_lintable_content_deleter(
     assert tmp_updated_lintable.content == updated_content
     del tmp_updated_lintable.content
     assert tmp_updated_lintable.content == content
+
+
+@pytest.mark.parametrize(
+    ("path", "result"),
+    (
+        pytest.param("foo", "foo", id="rel"),
+        pytest.param(os.path.expanduser("~/xxx"), "~/xxx", id="rel-to-home"),
+        pytest.param("/a/b/c", "/a/b/c", id="absolute"),
+        pytest.param(
+            "examples/playbooks/roles", "examples/roles", id="resolve-symlink"
+        ),
+    ),
+)
+def test_normpath_path(path: str, result: str) -> None:
+    """Tests behavior of normpath."""
+    assert normpath_path(path) == Path(result)