tests: add test for align_layout()

Author: szhorvat

tests/test_layouts.py

@@ -1,6 +1,6 @@
 import unittest
 from math import hypot
-from igraph import Graph, Layout, BoundingBox, InternalError
+from igraph import Graph, Layout, BoundingBox, InternalError, align_layout
 from igraph import umap_compute_weights
 
 
@@ -452,6 +452,13 @@ def testDRL(self):
         lo = g.layout("drl")
         self.assertTrue(isinstance(lo, Layout))
 
+    def testAlign(self):
+        g = Graph.Ring(3, circular=False)
+        lo = Layout([[1,1], [2,2], [3,3]])
+        lo = align_layout(g, lo)
+        self.assertTrue(isinstance(lo, Layout))
+        self.assertTrue(all(abs(lo[i][1]) < 1e-10 for i in range(3)))
+
 
 def suite():
     layout_suite = unittest.defaultTestLoader.loadTestsFromTestCase(LayoutTests)