feat: add checksum to item links in collections TDE-1138 (#953)

* feat: add checksum to item links in collections

* fix: formatting

* fix: update checksum after rebase

* fix: remove copy paste error

* fix: refactor didn't update docstring

* fix: simplify function as only called once

scripts/stac/imagery/collection.py

@@ -129,20 +129,21 @@ def add_item(self, item: Dict[Any, Any]) -> None:
             item: STAC Item to add
         """
         item_self_link = next((feat for feat in item["links"] if feat["rel"] == "self"), None)
+        file_checksum = checksum.multihash_as_hex(json.dumps(item).encode("utf-8"))
         if item_self_link:
-            self.add_link(href=item_self_link["href"])
+            self.add_link(href=item_self_link["href"], file_checksum=file_checksum)
             self.update_temporal_extent(item["properties"]["start_datetime"], item["properties"]["end_datetime"])
             self.update_spatial_extent(item["bbox"])
 
-    def add_link(self, href: str, rel: str = "item", file_type: str = "application/json") -> None:
+    def add_link(self, href: str, file_checksum: str) -> None:
         """Add a `link` to the existing `links` list of the Collection.
 
         Args:
             href: path
-            rel: type of link. Defaults to "item".
-            file_type: type of file pointed by the link. Defaults to "application/json".
+            file_checksum: Optional checksum of file.
         """
-        self.stac["links"].append({"rel": rel, "href": href, "type": file_type})
+        link = {"rel": "item", "href": href, "type": "application/json", "file:checksum": file_checksum}
+        self.stac["links"].append(link)
 
     def add_providers(self, providers: List[Provider]) -> None:
         """Add a list of Providers to the existing list of `providers` of the Collection.

scripts/stac/imagery/tests/collection_test.py

@@ -130,7 +130,12 @@ def test_add_item(mocker: MockerFixture, metadata: CollectionMetadata, subtests:
     collection.add_item(item.stac)
 
     with subtests.test():
-        assert {"rel": "item", "href": "./BR34_5000_0304.json", "type": "application/json"} in collection.stac["links"]
+        assert {
+            "file:checksum": "1220a049888b3971d9ed3fd52b830cfeb379d7069d6b7a927456bcf1fabab0ec4f46",
+            "rel": "item",
+            "href": "./BR34_5000_0304.json",
+            "type": "application/json",
+        } in collection.stac["links"]
 
     with subtests.test():
         assert collection.stac["extent"]["temporal"]["interval"] == [[start_datetime, end_datetime]]