Ensure combining registries preserves the rest of the attributes.

Author: Julian

referencing/_core.py

@@ -304,8 +304,19 @@ def combine(self, *registries: Registry[D]) -> Registry[D]:
         """
         Combine together one or more other registries, producing a unified one.
         """
-        contents = (registry._resources for registry in registries)
-        return evolve(self, resources=self._resources.update(*contents))  # type: ignore[reportUnknownMemberType]  # noqa: E501
+        anchors = self._anchors
+        resources = self._resources
+        uncrawled = self._uncrawled
+        for registry in registries:
+            anchors = anchors.update(registry._anchors)  # type: ignore[reportUnknownMemberType]  # noqa: E501
+            resources = resources.update(registry._resources)  # type: ignore[reportUnknownMemberType]  # noqa: E501
+            uncrawled = uncrawled.update(registry._uncrawled)  # type: ignore[reportUnknownMemberType]  # noqa: E501
+        return evolve(
+            self,
+            anchors=anchors,
+            resources=resources,
+            uncrawled=uncrawled,
+        )
 
     def resolver(self, base_uri: URI = "") -> Resolver[D]:
         """

referencing/tests/test_core.py

@@ -1,3 +1,4 @@
+from pyrsistent import pmap
 import pytest
 
 from referencing import Anchor, Registry, Resource, Specification, exceptions
@@ -177,22 +178,39 @@ def test_combine(self):
         one = Resource.opaque(contents={})
         two = ID_AND_CHILDREN.create_resource({"foo": "bar"})
         three = ID_AND_CHILDREN.create_resource({"baz": "quux"})
+        four = ID_AND_CHILDREN.create_resource({"anchors": {"foo": 12}})
 
         first = Registry({"http://example.com/1": one})
-        second = Registry({"http://example.com/foo/bar": two})
+        second = Registry().with_resource("http://example.com/foo/bar", two)
         third = Registry(
             {
                 "http://example.com/1": one,
                 "http://example.com/baz": three,
             },
         )
-        assert first.combine(second, third) == Registry(
+        fourth = (
+            Registry()
+            .with_resource(
+                "http://example.com/foo/quux",
+                four,
+            )
+            .crawl()
+        )
+        assert first.combine(second, third, fourth) == Registry(
             [
                 ("http://example.com/1", one),
-                ("http://example.com/foo/bar", two),
                 ("http://example.com/baz", three),
+                ("http://example.com/foo/quux", four),
             ],
-        )
+            anchors=pmap(
+                {
+                    ("http://example.com/foo/quux", "foo"): Anchor(
+                        name="foo",
+                        resource=ID_AND_CHILDREN.create_resource(12),
+                    ),
+                },
+            ),
+        ).with_resource("http://example.com/foo/bar", two)
 
     def test_combine_with_uncrawled_resources(self):
         one = Resource.opaque(contents={})