feat: Add is_editable wrapper function (#37)

<!-- readthedocs-preview pep610 start -->
----
📚 Documentation preview 📚:
https://pep610--37.org.readthedocs.build/en/37/

<!-- readthedocs-preview pep610 end -->

.readthedocs.yaml

@@ -3,7 +3,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.11"
+    python: "3.12"
   jobs:
     post_checkout:
       - git fetch --unshallow || true

docs/index.md

@@ -83,3 +83,7 @@ else:
 ```{eval-rst}
 .. autofunction:: pep610.read_from_distribution
 ```
+
+```{eval-rst}
+.. autofunction:: pep610.is_editable
+```

src/pep610/__init__.py

@@ -7,7 +7,7 @@
 import typing as t
 from dataclasses import dataclass
 from functools import singledispatch
-from importlib.metadata import version
+from importlib.metadata import distribution, version
 
 if t.TYPE_CHECKING:
     import sys
@@ -325,13 +325,38 @@ def read_from_distribution(dist: Distribution) -> VCSData | ArchiveData | DirDat
 
     Returns:
         The parsed PEP 610 file.
+
+    >>> import importlib.metadata
+    >>> dist = importlib.metadata.distribution("pep610")
+    >>> read_from_distribution(dist)  # doctest: +SKIP
+    DirData(url='file:///home/user/pep610', dir_info=DirInfo(editable=False))
     """
     if contents := dist.read_text("direct_url.json"):
         return _parse(contents)
 
     return None
 
 
+def is_editable(distribution_name: str) -> bool:
+    """Wrapper around :func:`read_from_distribution` to check if a distribution is editable.
+
+    Args:
+        distribution_name: The distribution name.
+
+    Returns:
+        Whether the distribution is editable.
+
+    Raises:
+        importlib_metadata.PackageNotFoundError: If the distribution is not found.
+
+    >>> is_editable("pep610")  # doctest: +SKIP
+    False
+    """  # noqa: DAR402, RUF100
+    dist = distribution(distribution_name)
+    data = read_from_distribution(dist)
+    return isinstance(data, DirData) and data.dir_info.is_editable()
+
+
 def write_to_distribution(dist: PathDistribution, data: dict) -> int:
     """Write the direct URL data to a distribution.
 

tests/test_parse.py

@@ -15,6 +15,7 @@
     HashData,
     VCSData,
     VCSInfo,
+    is_editable,
     read_from_distribution,
     to_dict,
     write_to_distribution,
@@ -321,3 +322,54 @@ def test_no_file(tmp_path: Path):
     """Test that a missing file is read back as None."""
     dist = Distribution.at(tmp_path)
     assert read_from_distribution(dist) is None
+
+
+@pytest.mark.parametrize(
+    ("data", "expected"),
+    [
+        pytest.param(
+            {
+                "url": "file:///home/user/project",
+                "dir_info": {"editable": True},
+            },
+            True,
+            id="editable",
+        ),
+        pytest.param(
+            {
+                "url": "file:///home/user/project",
+                "dir_info": {"editable": False},
+            },
+            False,
+            id="not_editable",
+        ),
+        pytest.param(
+            {
+                "url": "file:///home/user/project",
+                "dir_info": {},
+            },
+            False,
+            id="no_editable_info",
+        ),
+        pytest.param(
+            {
+                "url": "https://github.com/pypa/pip.git",
+                "vcs_info": {
+                    "vcs": "git",
+                    "requested_revision": "1.3.1",
+                    "resolved_revision_type": "tag",
+                    "commit_id": "7921be1537eac1e97bc40179a57f0349c2aee67d",
+                },
+            },
+            False,
+            id="vcs_git",
+        ),
+    ],
+)
+def test_is_editable(tmp_path: Path, monkeypatch: pytest.MonkeyPatch, data: dict, expected: bool):  # noqa: FBT001
+    """Test the is_editable function."""
+    dist = Distribution.at(tmp_path)
+    write_to_distribution(dist, data)
+
+    monkeypatch.setattr("pep610.distribution", lambda _: dist)
+    assert is_editable("my_package") is expected