Add move extension move test

tests/scadnano_tests.py

@@ -91,7 +91,7 @@ def test_strand__loopouts_with_labels_to_json(self) -> None:
         self.assertEqual(1, len(design_from_json.strands))
         self.assertEqual(expected_strand, design_from_json.strands[0])
 
-    def test_strand__extension_3p_from_to(self) -> None:
+    def test_strand__3p_extension(self) -> None:
         design = self.design_6helix
         sb = design.draw_strand(0, 0)
         sb.to(10)
@@ -105,7 +105,7 @@ def test_strand__extension_3p_from_to(self) -> None:
         self.assertEqual(1, len(design.strands))
         self.assertEqual(expected_strand, design.strands[0])
 
-    def test_strand__extension_5p(self) -> None:
+    def test_strand__5p_extension(self) -> None:
         design = self.design_6helix
         sb = design.draw_strand(0, 0)
 
@@ -120,7 +120,7 @@ def test_strand__extension_5p(self) -> None:
         self.assertEqual(1, len(design.strands))
         self.assertEqual(expected_strand, design.strands[0])
 
-    def test_strand__update_to_after_extension_5p_ok(self) -> None:
+    def test_strand__update_to_after_5p_extension_ok(self) -> None:
         design = self.design_6helix
         sb = design.draw_strand(0, 0)
 
@@ -136,6 +136,21 @@ def test_strand__update_to_after_extension_5p_ok(self) -> None:
         self.assertEqual(1, len(design.strands))
         self.assertEqual(expected_strand, design.strands[0])
 
+    def test_strand__move_after_5p_extension_ok(self) -> None:
+        design = self.design_6helix
+        sb = design.draw_strand(0, 0)
+
+        sb.extension(5)
+        sb.move(15)
+
+        expected_strand: sc.Strand = sc.Strand([
+            sc.Extension(5),
+            sc.Domain(0, True, 0, 15),
+        ])
+
+        self.assertEqual(1, len(design.strands))
+        self.assertEqual(expected_strand, design.strands[0])
+
     def test_strand__lone_extension_should_not_add_strand(self) -> None:
         design = self.design_6helix
         sb = design.draw_strand(0, 0)
@@ -153,6 +168,15 @@ def test_strand__to_after_non_5p_extension_should_raise_error(self) -> None:
         with self.assertRaises(sc.IllegalDesignError):
             sb.to(15)
 
+    def test_strand__move_after_non_5p_extension_should_raise_error(self) -> None:
+        design = self.design_6helix
+        sb = design.draw_strand(0, 0)
+        sb.move(10)
+        sb.extension(5)
+
+        with self.assertRaises(sc.IllegalDesignError):
+            sb.move(5)
+
     def test_strand__cross_after_extension_should_raise_error(self) -> None:
         design = self.design_6helix
         sb = design.draw_strand(0, 0)