tests for compositing operations

tests/python_tests/compositing_test.py

@@ -0,0 +1,28 @@
+#encoding: utf8
+
+from nose.tools import *
+import os,sys
+from utilities import execution_path
+from utilities import Todo
+import 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('.'))
+
+def test_compare_images():
+    b = mapnik.Image.open('./images/support/b.png')
+    for name in mapnik.CompositeOp.names:
+        a = mapnik.Image.open('./images/support/a.png')
+        a.composite(b,getattr(mapnik.CompositeOp,name))
+        actual = '/tmp/mapnik-comp-op-test-' + name + '.png'
+        expected = 'images/composited/' + name + '.png'
+        a.save(actual)
+        expected_im = mapnik.Image.open(expected)
+        # compare them
+        eq_(a.tostring(),expected_im.tostring(), 'failed comparing actual (%s) and expected(%s)' % (actual,'tests/python_tests/'+ expected))
+
+if __name__ == "__main__":
+    setup()
+    [eval(run)() for run in dir() if 'test_' in run]