Add basic test for Basemap.arcgisimage with cache directory

Author: molinav

packages/basemap/src/mpl_toolkits/basemap/__init__.py

@@ -4353,7 +4353,7 @@ def arcgisimage(self, server="http://server.arcgisonline.com/ArcGIS",
         ]) % (server, service, xmin, ymin, xmax, ymax, self.epsg, self.epsg, xpixels, ypixels, dpi)
 
         # Print URL in verbose mode.
-        if verbose:
+        if verbose:  # pragma: no cover
             print(basemap_url)
 
         # Try to return fast if cache is enabled.
@@ -4367,7 +4367,7 @@ def arcgisimage(self, server="http://server.arcgisonline.com/ArcGIS",
             # Return fast if the image is already in the cache.
             cache_path = os.path.join(cachedir, filename)
             if os.path.isfile(cache_path):
-                if verbose:
+                if verbose:  # pragma: no cover
                     print("Image already in cache")
                 img = Image.open(cache_path)
                 return self.imshow(img, ax=ax, origin="upper")

packages/basemap/test/mpl_toolkits/basemap/test_Basemap.py

@@ -1,5 +1,8 @@
 """Import test for the :mod:`mpl_toolkits.basemap.Basemap` class."""
 
+import os
+import shutil
+import tempfile
 import datetime as dt
 try:
     import unittest2 as unittest
@@ -145,6 +148,39 @@ def test_arcgisimage_with_cyl(self, axs=None, axslen0=10):
         axs_children = axs_obj.get_children()
         self.assertEqual(len(axs_children), axslen0 + 1)
 
+    @unittest.skipIf(PIL is None, reason="pillow unavailable")
+    def test_arcgisimage_with_cyl_using_cache(self, axs=None, axslen0=10):
+        """Test showing an ArcGIS image as background."""
+
+        axs_obj = plt.gca() if axs is None else axs
+        axs_children = axs_obj.get_children()
+        self.assertEqual(len(axs_children), axslen0)
+
+        bmap = Basemap(ax=axs, projection="cyl", resolution=None,
+                       llcrnrlon=-90, llcrnrlat=30,
+                       urcrnrlon=-60, urcrnrlat=60)
+
+        cachedir = tempfile.mkdtemp(prefix="tmp-basemap-cachedir-")
+        try:
+            # Check that the cache is initially empty.
+            self.assertEqual(len(os.listdir(cachedir)), 0)
+            # Check that the first call populates the cache.
+            img = bmap.arcgisimage(verbose=False, cachedir=cachedir)
+            self.assertEqual(len(os.listdir(cachedir)), 1)
+            # Check output properties after the first call.
+            self.assertIsInstance(img, AxesImage)
+            axs_children = axs_obj.get_children()
+            self.assertEqual(len(axs_children), axslen0 + 1)
+            # Check that the second call does not update the cache.
+            img = bmap.arcgisimage(verbose=False, cachedir=cachedir)
+            self.assertEqual(len(os.listdir(cachedir)), 1)
+            # Check output properties after the second call.
+            self.assertIsInstance(img, AxesImage)
+            axs_children = axs_obj.get_children()
+            self.assertEqual(len(axs_children), axslen0 + 2)
+        finally:
+            shutil.rmtree(cachedir)
+
     def _test_basemap_data_warpimage(self, method, axs=None, axslen0=10):
         """Test drawing a map background from :mod:`basemap_data`."""