add unit tests for rasterlite plugin

tests/python_tests/rasterlite_test.py

@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+
+from nose.tools import *
+from utilities import execution_path, run_all, contains_word, get_unique_colors
+
+import os, mapnik
+
+def setup():
+    # All of the paths used are relative, if we run the tests
+    # from another directory we need to chdir()
+    os.chdir(execution_path('.'))
+
+
+if 'rasterlite' in mapnik.DatasourceCache.plugin_names():
+
+    def test_rasterlite():
+        ds = mapnik.Rasterlite(
+            file = '../data/rasterlite/globe.sqlite',
+            table = 'globe'
+            )
+        e = ds.envelope()
+
+        assert_almost_equal(e.minx,-180, places=5)
+        assert_almost_equal(e.miny, -90, places=5)
+        assert_almost_equal(e.maxx, 180, places=5)
+        assert_almost_equal(e.maxy,  90, places=5)
+        eq_(len(ds.fields()),0)
+        query = mapnik.Query(ds.envelope())
+        for fld in ds.fields():
+            query.add_property_name(fld)
+        fs = ds.features(query)
+        feat = fs.next()
+        eq_(feat.id(),1)
+        eq_(feat.attributes,{})
+
+if __name__ == "__main__":
+    setup()
+    exit(run_all(eval(x) for x in dir() if x.startswith("test_")))