Removing assertion in drange to allow equal inputs (#246) and mimic behaviour of built-in method range

Fixes #66, since it now allows the bbox to have 0 width or 0 height
Added tests for Plane since it is the API that uses drange

pdfminer/utils.py

@@ -161,7 +161,6 @@ def fsplit(pred, objs):
 # drange
 def drange(v0, v1, d):
     """Returns a discrete range."""
-    assert v0 < v1, str((v0, v1, d))
     return range(int(v0)//d, int(v1+d)//d)
 
 

tests/test_utils.py

@@ -0,0 +1,40 @@
+from nose.tools import assert_equal
+
+from pdfminer.layout import LTComponent
+from pdfminer.utils import make_compat_str, Plane
+
+
+class TestPlane(object):
+    def test_find_nothing_in_empty_bbox(self):
+        plane, _ = self.given_plane_with_one_object()
+        result = list(plane.find((50, 50, 100, 100)))
+        assert_equal(result, [])
+
+    def test_find_nothing_after_removing(self):
+        plane, obj = self.given_plane_with_one_object()
+        plane.remove(obj)
+        result = list(plane.find((0, 0, 100, 100)))
+        assert_equal(result, [])
+
+    def test_find_object_in_whole_plane(self):
+        plane, obj = self.given_plane_with_one_object()
+        result = list(plane.find((0, 0, 100, 100)))
+        assert_equal(result, [obj])
+
+    def test_find_if_object_is_smaller_than_gridsize(self):
+        plane, obj = self.given_plane_with_one_object(object_size=1, gridsize=100)
+        result = list(plane.find((0, 0, 100, 100)))
+        assert_equal(result, [obj])
+
+    def test_find_object_if_much_larger_than_gridsize(self):
+        plane, obj = self.given_plane_with_one_object(object_size=100, gridsize=10)
+        result = list(plane.find((0, 0, 100, 100)))
+        assert_equal(result, [obj])
+
+    @staticmethod
+    def given_plane_with_one_object(object_size=50, gridsize=50):
+        bounding_box = (0, 0, 100, 100)
+        plane = Plane(bounding_box, gridsize)
+        obj = LTComponent((0, 0, object_size, object_size))
+        plane.add(obj)
+        return plane, obj