swap_link first working version

swap_link.py

@@ -0,0 +1,32 @@
+# swap_link.py
+# Replace a link file with another one pointing to a new target
+#
+
+from pathlib import Path
+from os.path import relpath # won't be necessary with Python 3.12 thanks to walk_up arg in relative_to()
+
+def swap_link(lnk, tgt):
+    #lnk: symbolic link to swap
+    #tgt: target for new link
+    lnpath = Path(lnk)
+    if not lnpath.is_symlink():
+        raise Exception("First argument is not a symbolic link")
+    elif lnpath.exists():
+        raise Exception("Link is not broken")
+
+    tpath = Path(tgt)
+    if tpath.is_symlink():
+        if not tpath.exists():
+            raise Exception("Target is also a broken link!")
+        elif tpath.readlink().resolve() == lnpath.resolve() :
+            raise Exception("Target is a link to link to be fixed...")
+    
+    try:
+        lnpath.unlink()
+    except Exception(e):
+        raise Exception("Failed to unlink lnk. Check permissions!")
+
+    lnpath = Path(lnk)
+
+    sym_path = relpath(tgt, lnk)[3:]
+    lnpath.symlink_to(sym_path)

test/test_search_file.py

@@ -4,7 +4,6 @@ import io
 from search_file import print_num_list, search_all_match, select_path
 import search_file
 
-# TODO: gros TODO icitte. Presque rien de fait!
 
 class TestSearchFile(unittest.TestCase):
 

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
+