fix setter failing in github actions

dask arrays are not supposed to cache results from reads, so if you change the data that the dask array wraps you should get the updated data on the next read.
This does not seem to be happening for dask arrays wrapping in-memory numpy arrays on some hardware. It is consistent behavior in the github actions but I cannot recreate it locally.

funlib/persistence/arrays/array.py

@@ -311,6 +311,13 @@ def __setitem__(self, key, value: np.ndarray):
 
                 self._source_data[region_slices] = value
 
+            # If the source data is an in-memory numpy array, writing to the numpy
+            # array does not always result in the dask array reading the new data.
+            # It seems to be a caching issue. To work around this, we create a new
+            # dask array from the source data.
+            if isinstance(self._source_data, np.ndarray):
+                self.data = da.from_array(self._source_data)
+
         else:
             raise RuntimeError(
                 "This array is not writeable since you have applied a custom callable "

tests/test_array.py

@@ -1,6 +1,6 @@
+import dask.array as da
 import numpy as np
 import pytest
-import dask.array as da
 
 from funlib.geometry import Coordinate, Roi
 from funlib.persistence.arrays import Array
@@ -73,13 +73,14 @@ def test_setitem():
 
     a = Array(np.zeros((2, 5)), (0, 0), (1, 1))
 
-    a[Roi((0, 0), (2, 5))] = np.arange(0, 10).reshape(2, 5)
-    assert a[Coordinate((0, 0))] == 0
-    assert a[Coordinate((0, 1))] == 1
-    assert a[Coordinate((0, 2))] == 2
-    assert a[Coordinate((1, 0))] == 5
-    assert a[Coordinate((1, 1))] == 6
-    assert a[Coordinate((1, 4))] == 9
+    data = np.arange(0, 10).reshape(2, 5)
+    a[Roi((0, 0), (2, 5))] = data
+    assert a[Coordinate((0, 0))] == a._source_data[0, 0] == 0
+    assert a[Coordinate((0, 1))] == a._source_data[0, 1] == 1
+    assert a[Coordinate((0, 2))] == a._source_data[0, 2] == 2
+    assert a[Coordinate((1, 0))] == a._source_data[1, 0] == 5
+    assert a[Coordinate((1, 1))] == a._source_data[1, 1] == 6
+    assert a[Coordinate((1, 4))] == a._source_data[1, 4] == 9
 
     # set entirely with numpy array and channels