feat: restore Link.resolve_stac_object

Author: ircwaves

src/pystac/link.py

@@ -6,10 +6,11 @@
 
 from typing_extensions import deprecated
 
+import pystac
 from pystac.errors import STACError
 from pystac.media_type import MediaType
 from pystac.rel_type import RelType
-from pystac.utils import make_absolute_href, make_posix_style
+from pystac.utils import is_absolute_href, make_absolute_href, make_posix_style
 
 from .reader import Reader
 
@@ -203,6 +204,34 @@ def to_dict(self, transform_href: bool | None = None) -> dict[str, Any]:
             data["body"] = self.body
         return data
 
+    def resolve_stac_object(self, start_href: str = "") -> Link:
+        """Resolves a STAC object from the HREF of this link, if the link is not
+        already resolved.
+
+        Args:
+            start_href : Optional string to put ahead of the href in this Link.
+
+        NOTE: This uses reader.DEFAULT_READER to read the HREF, if necessary.
+        """
+        if self._target:
+            return self
+        elif self._href:
+            # If it's a relative link, base it off the parent.
+            target_href = self._href
+            if not is_absolute_href(target_href):
+                target_href = make_absolute_href(self._href, start_href=start_href)
+            try:
+                obj = pystac.read_file(target_href)
+            except Exception as e:
+                raise STACError(
+                    f"HREF: '{target_href}' does not resolve to a STAC object"
+                ) from e
+            self._target = obj
+        else:
+            raise ValueError("Cannot resolve STAC object without a target")
+
+        return self
+
     @override
     def __repr__(self) -> str:
         return f"Link(rel={self.rel}, href={self._href})"

tests/v1/test_link.py

@@ -85,13 +85,11 @@ def test_link_does_not_fail_if_href_is_none(item: pystac.Item) -> None:
     assert link.get_href() is None
 
 
-@pytest.mark.xfail(reason="STACObjects no longer have resolve_stac_object method")
 def test_resolve_stac_object_no_root_and_target_is_item(item: pystac.Item) -> None:
     link = Link("my rel", target=item)
     link.resolve_stac_object()
 
 
-@pytest.mark.xfail(reason="STACObjects no longer have resolve_stac_object method")
 @pytest.mark.skipif(os.name == "nt", reason="Non-windows test")
 def test_resolve_stac_object_throws_informative_error() -> None:
     link = Link("root", target="/a/b/foo.json")
@@ -101,7 +99,6 @@ def test_resolve_stac_object_throws_informative_error() -> None:
         link.resolve_stac_object()
 
 
-@pytest.mark.xfail(reason="STACObjects no longer have resolve_stac_object method")
 def test_resolved_self_href() -> None:
     catalog = Catalog(id="test", description="test desc")
     with TemporaryDirectory() as temporary_directory: