Allow installing relative paths that go outside tox root folder (#2554)

Co-authored-by: Bernát Gábor <[email protected]>
Fixes #2366

Author: ssbarnea

docs/changelog/2366.bugfix.rst

@@ -0,0 +1 @@
+Allow installing relative paths that go outside tox root folder. - by :user:`ssbarnea`.

src/tox/tox_env/python/pip/req/file.py

@@ -57,9 +57,14 @@ def __init__(self, req: str, options: dict[str, Any], from_file: str, lineno: in
                 else:
                     path = root / req
                 extra_part = f"[{','.join(sorted(extras))}]" if extras else ""
-                rel_path = str(path.resolve().relative_to(root))
-                if rel_path != "." and os.sep not in rel_path:  # prefix paths in cwd to not convert them to requirement
-                    rel_path = f".{os.sep}{rel_path}"
+                try:
+                    rel_path = str(path.resolve().relative_to(root))
+                    # prefix paths in cwd to not convert them to requirement
+                    if rel_path != "." and os.sep not in rel_path:
+                        rel_path = f".{os.sep}{rel_path}"
+                except ValueError:
+                    rel_path = str(path.resolve())
+
                 self._requirement = f"{rel_path}{extra_part}"
         self._options = options
         self._from_file = from_file

tests/tox_env/python/pip/req/test_file.py

@@ -484,3 +484,11 @@ def test_requirement_via_file_protocol_na(tmp_path: Path) -> None:
     pattern = r"non-local file URIs are not supported on this platform: 'file://magic\.com\.*"
     with pytest.raises(ValueError, match=pattern):
         assert req_file.options
+
+
+def test_requirement_to_path_one_level_up(tmp_path: Path) -> None:
+    other_req = tmp_path / "other.txt"
+    other_req.write_text("-e ..")
+    req_file = RequirementsFile(other_req, constraint=False)
+    result = req_file.requirements
+    assert result[0].requirement == str(tmp_path.parent.resolve())

tests/tox_env/python/pip/test_req_file.py

@@ -30,13 +30,8 @@ def test_deps_with_requirements_with_hash(tmp_path: Path) -> None:
     """deps can point to a requirements file that has --hash."""
     exp_hash = "sha256:97a702083b0d906517b79672d8501eee470d60ae55df0fa9d4cfba56c7f65a82"
     requirements = tmp_path / "requirements.txt"
-    requirements.write_text(
-        f"foo==1 --hash {exp_hash}",
-    )
-    python_deps = PythonDeps(
-        raw="-r requirements.txt",
-        root=tmp_path,
-    )
+    requirements.write_text(f"foo==1 --hash {exp_hash}")
+    python_deps = PythonDeps(raw="-r requirements.txt", root=tmp_path)
     assert len(python_deps.requirements) == 1
     parsed_req = python_deps.requirements[0]
     assert str(parsed_req.requirement) == "foo==1"