test: expand builder encoding coverage

Author: BrianMichell

src/mdio/core/v1/builder.py

@@ -284,6 +284,10 @@ def _generate_encodings() -> dict:
             chunks = None
             if var.metadata is not None and var.metadata.chunk_grid is not None:
                 chunks = var.metadata.chunk_grid.configuration.chunk_shape
+                if isinstance(chunks[0], list):
+                    chunks = tuple(tuple(c) for c in chunks)
+                else:
+                    chunks = tuple(chunks)
             else:
                 # When no chunk_grid is provided, set chunks to shape to avoid chunking
                 dim_names = [d.name if isinstance(d, NamedDimension) else d for d in var.dimensions]
@@ -298,14 +302,19 @@ def _generate_encodings() -> dict:
             }
         return global_encodings
 
+    global_encodings = _generate_encodings()
     ds.to_mdio(
         store,
         mode=mode,
         zarr_format=2,
         consolidated=True,
         safe_chunks=False,
         compute=compute,
-        encoding=_generate_encodings(),
+        encoding=global_encodings,
         **kwargs,
     )
+
+    for var_name, encoding in global_encodings.items():
+        ds[var_name].encoding.update(encoding)
+
     return ds

tests/unit/test_builder_encoding.py

@@ -0,0 +1,65 @@
+import numpy as np
+from pathlib import Path
+
+from mdio.core.v1.builder import MDIODatasetBuilder
+
+
+def test_builder_populates_encodings(tmp_path: Path) -> None:
+    builder = MDIODatasetBuilder("encodings")
+    builder.add_dimension("x", 10)
+    builder.add_variable(
+        "var",
+        metadata={"chunkGrid": {"name": "regular", "configuration": {"chunkShape": [5]}}},
+    )
+    ds = builder.to_mdio(str(tmp_path / "enc.mdio"))
+
+    assert ds["x"].encoding["chunks"] == (10,)
+    assert ds["var"].encoding["chunks"] == (5,)
+
+
+def test_builder_populates_encodings_multiple(tmp_path: Path) -> None:
+    """Ensure encodings are populated for a more complex dataset."""
+
+    builder = MDIODatasetBuilder("encodings_multi")
+
+    # Add several dimensions
+    builder.add_dimension("x", 10)
+    builder.add_dimension("y", 20)
+    builder.add_dimension("z", 5)
+
+    # Add coordinates using different combinations of dimensions
+    builder.add_coordinate("x_coord", dimensions=["x"])
+    builder.add_coordinate("yz_coord", dimensions=["y", "z"])
+
+    # Add variables with explicit chunking across multiple dimensions
+    builder.add_variable(
+        "var_xy",
+        dimensions=["x", "y"],
+        metadata={"chunkGrid": {"name": "regular", "configuration": {"chunkShape": [5, 10]}}},
+    )
+    builder.add_variable(
+        "var_xyz",
+        dimensions=["x", "y", "z"],
+        metadata={"chunkGrid": {"name": "regular", "configuration": {"chunkShape": [5, 10, 5]}}},
+    )
+    builder.add_variable(
+        "var_z",
+        dimensions=["z"],
+        metadata={"chunkGrid": {"name": "regular", "configuration": {"chunkShape": [5]}}},
+    )
+
+    ds = builder.to_mdio(str(tmp_path / "enc_multi.mdio"))
+
+    # Dimension variables should have full-size chunks
+    assert ds["x"].encoding["chunks"] == (10,)
+    assert ds["y"].encoding["chunks"] == (20,)
+    assert ds["z"].encoding["chunks"] == (5,)
+
+    # Coordinate variables should inherit dimension chunking
+    assert ds["x_coord"].encoding["chunks"] == (10,)
+    assert ds["yz_coord"].encoding["chunks"] == (20, 5)
+
+    # Data variables should use the provided chunk shapes
+    assert ds["var_xy"].encoding["chunks"] == (5, 10)
+    assert ds["var_xyz"].encoding["chunks"] == (5, 10, 5)
+    assert ds["var_z"].encoding["chunks"] == (5,)