swap_link first working version

test/test_swap_link.py

@@ -0,0 +1,20 @@
+import unittest
+
+class TestSwapLink(unittest.TestCase):
+    
+    data_dir = "test/data/search_test"
+
+    def test_wrong_lnk_file(self):
+        with self.assertRaises(Exception):
+            swap_link(data_dir+"inexistent.txt", data_dir+"/subdir/match1.txt") # inexistent file
+        with self.assertRaises(Exception):
+            swap_link(data_dir+"/subdir1/match1.txt", data_dir+"/subdir/match1.txt") # non link file
+        with self.assertRaises(Exception):
+            swap_link(data_dir+"lnk_dir/ln_valid", data_dir+"/subdir/match1.txt") # not broken link
+        # TODO: no writing permission on file
+    
+    def test_wrong_tgt_file(self):
+        # TODO: non-existing target
+        # TODO: target is link to lnk file (can't have 2 symlinks pointing at one another)
+        True
+