WIP: Support icechunk stores

.gitignore

@@ -105,3 +105,4 @@ cdk.out/
 node_modules
 cdk.context.json
 *.nc
+.DS_Store

README.md

@@ -14,6 +14,8 @@ Example of application built with `titiler.xarray` [package](https://development
 # It's recommended to install dependencies in a virtual environment
 uv sync --dev
 export TEST_ENVIRONMENT=true  # set this when running locally to mock redis
+#optional: Disable caching
+#export TITILER_MULTIDIM_ENABLE_CACHE=false
 uv run uvicorn titiler.multidim.main:app --reload
 ```
 

pyproject.toml

@@ -41,8 +41,8 @@ dependencies = [
     "requests",
     "rioxarray",
     "s3fs",
-    "xarray",
-    "zarr>=2,<3",
+    "xarray>2025.07.1",
+    "zarr>3.1.0",
 ]
 
 [project.optional-dependencies]
@@ -56,6 +56,7 @@ lambda = [
 
 [dependency-groups]
 dev = [
+    "dask>=2025.9.1",
     "fakeredis>=2.23.5",
     "httpx",
     "ipykernel>=6.30.1",

src/titiler/multidim/reader.py

@@ -34,6 +34,8 @@ def __attrs_post_init__(self):
             group=self.group,
             decode_times=self.decode_times,
         )
+        print(f"DEBUG: Dataset id {id(self.ds)} opened from {self.src_path}")
+        print(f"DEBUG: {api_settings.enable_cache=}")
 
         if not ds and api_settings.enable_cache:
             # Serialize the dataset to bytes using pickle

tests/conftest.py

@@ -1,15 +1,37 @@
-"""titiler.multidim tests configuration."""
+"""Auto-parametrized fixture that runs both cache configurations."""
 
+import sys
 import pytest
 from fastapi.testclient import TestClient
 
 
-@pytest.fixture
-def app(monkeypatch):
-    """App fixture."""
+# This fixture will automatically parametrize ALL tests that use it
+@pytest.fixture(
+    params=[
+        pytest.param({"cache": True}, id="with_cache"),
+        pytest.param({"cache": False}, id="without_cache"),
+    ]
+)
+def app(request, monkeypatch):
+    """Auto-parametrized app fixture that runs tests with both cache configurations."""
+    config = request.param
+    enable_cache = config.get("cache", False)
+
+    # Set environment variables using monkeypatch (auto-cleanup)
     monkeypatch.setenv("TITILER_MULTIDIM_DEBUG", "TRUE")
     monkeypatch.setenv("TEST_ENVIRONMENT", "1")
+    monkeypatch.setenv(
+        "TITILER_MULTIDIM_ENABLE_CACHE", "TRUE" if enable_cache else "FALSE"
+    )
+
+    # Clear module cache to ensure fresh import
+    modules_to_clear = [
+        key for key in sys.modules.keys() if key.startswith("titiler.multidim")
+    ]
+    for module in modules_to_clear:
+        del sys.modules[module]
 
+    # Import and return the app
     from titiler.multidim.main import app
 
     with TestClient(app) as client:

tests/fixtures/generate_test_zarr.py

@@ -1,4 +1,4 @@
-"""Create zarr fixture."""
+"""Create zarr fixtures for v2 and v3."""
 
 import numpy as np
 import xarray as xr
@@ -8,31 +8,32 @@
 time_dim = 10
 lat_dim = 36
 lon_dim = 72
-chunk_size = (10, 10, 10)
+chunk_size = {"time": 10, "lat": 10, "lon": 10}
 
 # Create coordinates
 time = np.arange(time_dim)
-lat = np.linspace(-90 + res / 2, 90 - res / 2, lat_dim)
-lon = np.linspace(-180 + res / 2, 180 - res / 2, lon_dim)
+lat = np.linspace(-90.0 + res / 2, 90.0 - res / 2, lat_dim)
+lon = np.linspace(-180.0 + res / 2, 180.0 - res / 2, lon_dim)
 
+dtype = np.float64
 # Initialize variables with random data
 CDD0 = xr.DataArray(
-    np.random.rand(time_dim, lat_dim, lon_dim).astype(np.uint8),
+    np.random.rand(time_dim, lat_dim, lon_dim).astype(dtype),
     dims=("time", "lat", "lon"),
     name="CDD0",
 )
 DISPH = xr.DataArray(
-    np.random.rand(time_dim, lat_dim, lon_dim).astype(np.uint8),
+    np.random.rand(time_dim, lat_dim, lon_dim).astype(dtype),
     dims=("time", "lat", "lon"),
     name="DISPH",
 )
 FROST_DAYS = xr.DataArray(
-    np.random.rand(time_dim, lat_dim, lon_dim).astype(np.uint8),
+    np.random.rand(time_dim, lat_dim, lon_dim).astype(dtype),
     dims=("time", "lat", "lon"),
     name="FROST_DAYS",
 )
 GWETPROF = xr.DataArray(
-    np.random.rand(time_dim, lat_dim, lon_dim).astype(np.uint8),
+    np.random.rand(time_dim, lat_dim, lon_dim).astype(dtype),
     dims=("time", "lat", "lon"),
     name="GWETPROF",
 )
@@ -49,4 +50,17 @@
 )
 
 # Save dataset to a local Zarr store
-ds.to_zarr("tests/fixtures/test_zarr_store.zarr", mode="w")
+ds.to_zarr(
+    "tests/fixtures/zarr_store_v3.zarr",
+    mode="w",
+    zarr_format=3,
+    consolidated=False,
+)
+
+# Save dataset to a local Zarr store
+ds.to_zarr(
+    "tests/fixtures/zarr_store_v2.zarr",
+    mode="w",
+    zarr_format=2,
+    consolidated=True,
+)

tests/fixtures/responses/test_zarr_store_zarr_tilejson.json → tests/fixtures/responses/zarr_store_v2_zarr_tilejson.json

@@ -3,7 +3,7 @@
   "version": "1.0.0",
   "scheme": "xyz",
   "tiles": [
-    "http://testserver/tiles/WebMercatorQuad/{z}/{x}/{y}@1x?url=tests%2Ffixtures%2Ftest_zarr_store.zarr&variable=CDD0&decode_times=false&sel=time%3D0"
+    "http://testserver/tiles/WebMercatorQuad/{z}/{x}/{y}@1x?url=tests%2Ffixtures%2Fzarr_store_v2.zarr&variable=CDD0&decode_times=false&sel=time%3D0"
   ],
   "minzoom": 0,
   "maxzoom": 0,

tests/fixtures/responses/zarr_store_v3_zarr_info.json

@@ -0,0 +1,12 @@
+{
+    "bounds": [-180, -90.0, 180.0, 90.0],
+    "band_metadata": [],
+    "band_descriptions": [],
+    "dtype": "float64",
+    "nodata_type": "None",
+    "height": 36,
+    "count": 1,
+    "width": 72,
+    "attrs": {},
+    "name": "CDD0"
+}

tests/fixtures/responses/zarr_store_v3_zarr_tilejson.json

@@ -0,0 +1,12 @@
+{
+  "tilejson": "2.2.0",
+  "version": "1.0.0",
+  "scheme": "xyz",
+  "tiles": [
+    "http://testserver/tiles/WebMercatorQuad/{z}/{x}/{y}@1x?url=tests%2Ffixtures%2Fzarr_store_v3.zarr&variable=CDD0&decode_times=false&sel=time%3D0"
+  ],
+  "minzoom": 0,
+  "maxzoom": 0,
+  "bounds": [-180.0, -90.0, 180.0, 90.0],
+  "center": [0.0, 0.0, 0]
+}