Add migration for eo:epsg to proj:epsg

Author: duckontheweb

pystac/extensions/eo.py

@@ -24,7 +24,7 @@
     SummariesExtension,
 )
 from pystac.extensions.hooks import ExtensionHooks
-from pystac.extensions import view
+from pystac.extensions import view, projection
 from pystac.serialization.identify import STACJSONDescription, STACVersionID
 from pystac.utils import get_required, map_opt
 
@@ -557,6 +557,22 @@ def migrate(
                         ]
                         del obj["properties"]["eo:{}".format(field)]
 
+            # eo:epsg became proj:epsg
+            eo_epsg = PREFIX + "epsg"
+            proj_epsg = projection.PREFIX + "epsg"
+            if eo_epsg in obj["properties"] and proj_epsg not in obj["properties"]:
+                obj["properties"][proj_epsg] = obj["properties"].pop(eo_epsg)
+                obj["stac_extensions"] = obj.get("stac_extensions", [])
+                if (
+                    projection.ProjectionExtension.get_schema_uri()
+                    not in obj["stac_extensions"]
+                ):
+                    obj["stac_extensions"].append(
+                        projection.ProjectionExtension.get_schema_uri()
+                    )
+                if not any(prop.startswith(PREFIX) for prop in obj["properties"]):
+                    obj["stac_extensions"].remove(EOExtension.get_schema_uri())
+
         if version < "1.0.0-beta.1" and info.object_type == pystac.STACObjectType.ITEM:
             # gsd moved from eo to common metadata
             if "eo:gsd" in obj["properties"]: