Use Python code for downloading test file

tests/api/__init__.py

@@ -1,7 +1,22 @@
 import os
-os.system("""
-    ls /tmp/test_dem.tif > /dev/null
-    if [ $? -eq 0 ]; then exit; fi
-    wget https://coast.noaa.gov/htdata/raster2/elevation/NCEI_ninth_Topobathy_2014_8483/northeast_sandy/ncei19_n40x75_w073x75_2015v1.tif -O /tmp/fullsize_dem.tif
-    gdalwarp -tr 0.0005 0.0005 -r average -overwrite /tmp/fullsize_dem.tif /tmp/test_dem.tif
-""")
+import tempfile
+import urllib.request
+from pathlib import Path
+
+from rasterio.enums import Resampling
+
+from ocsmesh.raster import Raster
+
+
+# Find a better way!
+tif_url = (
+    'https://coast.noaa.gov/htdata/raster2/elevation/NCEI_ninth_Topobathy_2014_8483/northeast_sandy/ncei19_n40x75_w073x75_2015v1.tif'
+)
+TEST_FILE = os.path.join(tempfile.gettempdir(), 'test_dem.tif')
+if not Path(TEST_FILE).exists():
+    with tempfile.NamedTemporaryFile() as tfp:
+        urllib.request.urlretrieve(tif_url, filename=tfp.name)
+        r = Raster(tfp.name)
+        r.resampling_method = Resampling.average
+        r.resample(scaling_factor=0.01)
+        r.save(TEST_FILE)

tests/api/hfun.py

@@ -13,6 +13,7 @@
 
 import ocsmesh
 
+from tests.api import TEST_FILE
 from tests.api.common import (
     topo_2rast_1mesh,
 )
@@ -492,7 +493,7 @@ def test_hfun_fast_extent(self):
 class SizeFromMesh(unittest.TestCase):
 
     def setUp(self):
-        rast = ocsmesh.raster.Raster('/tmp/test_dem.tif')
+        rast = ocsmesh.raster.Raster(TEST_FILE)
 
         hfun_orig = ocsmesh.hfun.hfun.Hfun(rast, hmin=100, hmax=1500)
         hfun_orig.add_contour(level=0, expansion_rate=0.001, target_size=100)
@@ -530,7 +531,7 @@ def test_hfun_raster_cfl_constraint_support(self):
         courant_hi = 0.8
         courant_lo = 0.2
 
-        rast = ocsmesh.raster.Raster('/tmp/test_dem.tif')
+        rast = ocsmesh.raster.Raster(TEST_FILE)
 
         hfun_raster = ocsmesh.hfun.hfun.Hfun(rast, hmin=100, hmax=5000)
         hfun_raster.add_courant_num_constraint(
@@ -586,7 +587,7 @@ def test_hfun_raster_cfl_constraint_support(self):
         )
 
     def test_hfun_raster_cfl_constraint_io(self):
-        rast = ocsmesh.raster.Raster('/tmp/test_dem.tif')
+        rast = ocsmesh.raster.Raster(TEST_FILE)
         hfun_raster = ocsmesh.hfun.hfun.Hfun(rast, hmin=100, hmax=5000)
         self.assertRaises(
             ValueError,
@@ -614,8 +615,8 @@ def test_hfun_coll_cfl_constraint(self):
             # TODO: Add subTest
 
             # Creating adjacent rasters from the test raster
-            rast1 = ocsmesh.raster.Raster('/tmp/test_dem.tif')
-            rast2 = ocsmesh.raster.Raster('/tmp/test_dem.tif')
+            rast1 = ocsmesh.raster.Raster(TEST_FILE)
+            rast2 = ocsmesh.raster.Raster(TEST_FILE)
             bounds = rast1.bbox.bounds
             bbox1 = geometry.box(
                 bounds[0], bounds[1], (bounds[0] + bounds[2]) / 2, bounds[3]