added migration from 1.2 to 1.3

Author: jonas-hurst

pystac/extensions/mlm.py

@@ -2107,7 +2107,31 @@ def _migrate_1_1_to_1_2(obj: dict[str, Any]) -> None:
 
     @staticmethod
     def _migrate_1_2_to_1_3(obj: dict[str, Any]) -> None:
-        pass
+        bands_obj = obj["properties"]["mlm:input"]
+
+        if not bands_obj:
+            return
+
+        if "raster:bands" not in obj["properties"]:
+            return
+        raster_bands = obj["properties"]["raster:bands"]
+
+        # make sure all raster_bands have a name prop with length>0
+        names_properties_valid = all(
+            "name" in band and len(band["name"]) > 0 for band in raster_bands
+        )
+        if not names_properties_valid:
+            raise STACError(
+                "Error migrating stac:mlm version: In mlm>=1.3, each band in "
+                'raster:bands is required to have a property "name"'
+            )
+
+        # copy the raster:bands to assets
+        for asset_name in obj["assets"]:
+            asset = obj["assets"][asset_name]
+            if "mlm:model" not in asset["roles"]:
+                continue
+            asset["raster:bands"] = raster_bands
 
     @staticmethod
     def _migrate_1_3_to_1_4(obj: dict[str, Any]) -> None:

tests/extensions/test_mlm.py

@@ -1121,6 +1121,69 @@ def test_migration_1_1_to_1_2() -> None:
     MLMExtensionHooks._migrate_1_1_to_1_2(data)
 
 
+@pytest.mark.parametrize(
+    "inp_bands, raster_bands, valid",
+    (
+        ([], None, True),
+        (
+            ["B02", "B03"],
+            [
+                {"name": "B02", "data_type": "float64"},
+                {"name": "B03", "data_type": "float64"},
+            ],
+            True,
+        ),
+        (
+            ["B02", "B03"],
+            [
+                {"name": "", "data_type": "float64"},
+                {"name": "", "data_type": "float64"},
+            ],
+            False,
+        ),
+        (
+            ["B02", "B03"],
+            [
+                {"name": "B02", "data_type": "float64"},
+                {"name": "", "data_type": "float64"},
+            ],
+            False,
+        ),
+        (
+            ["B02", "B03"],
+            [{"name": "B02", "data_type": "float64"}, {"data_type": "float64"}],
+            False,
+        ),
+        (
+            ["B02", "B03"],
+            [{"name": "", "data_type": "float64"}, {"data_type": "float64"}],
+            False,
+        ),
+        (["B02", "B03"], [{"data_type": "float64"}, {"data_type": "float64"}], False),
+    ),
+)
+def test_migration_1_2_to_1_3(
+    inp_bands: list[str], raster_bands: list[dict[str, Any]], valid: bool
+) -> None:
+    data: dict[str, Any] = {
+        "properties": {"mlm:input": {}},
+        "assets": {"asset1": {"roles": ["data"]}, "asset2": {"roles": ["mlm:model"]}},
+    }
+
+    if inp_bands:
+        data["properties"]["mlm:input"]["bands"] = inp_bands
+        data["properties"]["raster:bands"] = raster_bands
+
+    if valid:
+        MLMExtensionHooks._migrate_1_2_to_1_3(data)
+        if raster_bands:
+            assert "raster:bands" not in data["assets"]["asset1"]
+            assert "raster:bands" in data["assets"]["asset2"]
+    else:
+        with pytest.raises(STACError):
+            MLMExtensionHooks._migrate_1_2_to_1_3(data)
+
+
 @pytest.mark.parametrize(
     ("norm_by_channel", "norm_type", "norm_clip", "statistics", "value_scaling"),
     (