Add tests for version extension that test full_copy.

This commit adds two tests, one for each of the Item and Collection
extensions of the Version extension. The test checks that when items
or collections are linked by the version links (predecessor, successor,
or latest_version), that a full copy will end up with a catalog that
has those links point to the correct object instances. If this test
were to fail, that would indicate that the STAC object linked to by
the version links was a separate copy of item or collection, which is incorrect.

Author: lossyrob

tests/extensions/test_version.py

@@ -5,6 +5,7 @@
 
 import pystac
 from pystac.extensions import version
+from tests.utils import TestCases
 
 URL_TEMPLATE = 'http://example.com/catalog/%s.json'
 
@@ -104,6 +105,39 @@ def test_all_links(self):
         self.item.ext.version.apply(self.version, deprecated, latest, predecessor, successor)
         self.item.validate()
 
+    def test_full_copy(self):
+        cat = TestCases.test_case_1()
+
+        # Fetch two items from the catalog
+        item1 = cat.get_item('area-1-1-imagery', recursive=True)
+        item2 = cat.get_item('area-2-2-imagery', recursive=True)
+
+        # Enable the version extension on each, and link them
+        # as if they are different versions of the same Item
+        item1.ext.enable(pystac.Extensions.VERSION)
+        item2.ext.enable(pystac.Extensions.VERSION)
+
+        item1.ext.version.apply(version='2.0', predecessor=item2)
+        item2.ext.version.apply(version='1.0', successor=item1, latest=item1)
+
+        # Make a full copy of the catalog
+        cat_copy = cat.full_copy()
+
+        # Retrieve the copied version of the items
+        item1_copy = cat_copy.get_item('area-1-1-imagery', recursive=True)
+        item2_copy = cat_copy.get_item('area-2-2-imagery', recursive=True)
+
+        # Check to see if the version links point to the instances of the
+        # item objects as they should.
+
+        predecessor = item1_copy.get_single_link(version.PREDECESSOR_VERSION).target
+        successor = item2_copy.get_single_link(version.SUCCESSOR_VERSION).target
+        latest = item2_copy.get_single_link(version.LATEST_VERSION).target
+
+        self.assertIs(predecessor, item2_copy)
+        self.assertIs(successor, item1_copy)
+        self.assertIs(latest, item1_copy)
+
 
 def make_collection(year):
     asset_id = 'my/collection/of/things'
@@ -202,6 +236,39 @@ def test_validate_all(self):
         self.collection.ext.version.apply(self.version, deprecated, latest, predecessor, successor)
         self.collection.validate()
 
+    def test_full_copy(self):
+        cat = TestCases.test_case_1()
+
+        # Fetch two collections from the catalog
+        col1 = cat.get_child('area-1-1', recursive=True)
+        col2 = cat.get_child('area-2-2', recursive=True)
+
+        # Enable the version extension on each, and link them
+        # as if they are different versions of the same Collection
+        col1.ext.enable(pystac.Extensions.VERSION)
+        col2.ext.enable(pystac.Extensions.VERSION)
+
+        col1.ext.version.apply(version='2.0', predecessor=col2)
+        col2.ext.version.apply(version='1.0', successor=col1, latest=col1)
+
+        # Make a full copy of the catalog
+        cat_copy = cat.full_copy()
+
+        # Retrieve the copied version of the items
+        col1_copy = cat_copy.get_child('area-1-1', recursive=True)
+        col2_copy = cat_copy.get_child('area-2-2', recursive=True)
+
+        # Check to see if the version links point to the instances of the
+        # col objects as they should.
+
+        predecessor = col1_copy.get_single_link(version.PREDECESSOR_VERSION).target
+        successor = col2_copy.get_single_link(version.SUCCESSOR_VERSION).target
+        latest = col2_copy.get_single_link(version.LATEST_VERSION).target
+
+        self.assertIs(predecessor, col2_copy)
+        self.assertIs(successor, col1_copy)
+        self.assertIs(latest, col1_copy)
+
 
 if __name__ == '__main__':
     unittest.main()