Merge 3b26851e8e into 712b30a445

README.md

@@ -181,6 +181,7 @@ mapped to extended configuration dictionaries.
 | `create` | When true, create parent directories to the link as needed. (default: false) |
 | `relink` | Removes the old target if it's a symlink (default: false) |
 | `force` | Force removes the old target, file or folder, and forces a new link (default: false) |
+| `backup-root` | In case of `force` or `relink` backup the old target to `backup-root` (default: no backup) |
 | `relative` | Use a relative path to the source when creating the symlink (default: false, absolute links) |
 | `canonicalize` | Resolve any symbolic links encountered in the source to symlink to the canonical path (default: true, real paths) |
 | `if` | Execute this in your `$SHELL` and only link if it is successful. |

dotbot/plugins/link.py

@@ -2,6 +2,7 @@ import glob
 import os
 import shutil
 import sys
+import datetime
 
 from ..plugin import Plugin
 from ..util import shell_command
@@ -32,6 +33,7 @@ class Link(Plugin):
             canonical_path = defaults.get("canonicalize", defaults.get("canonicalize-path", True))
             force = defaults.get("force", False)
             relink = defaults.get("relink", False)
+            backup_root = defaults.get("backup-root", None)
             create = defaults.get("create", False)
             use_glob = defaults.get("glob", False)
             base_prefix = defaults.get("prefix", "")
@@ -47,6 +49,7 @@ class Link(Plugin):
                 )
                 force = source.get("force", force)
                 relink = source.get("relink", relink)
+                backup_root = source.get("backup-root", backup_root)
                 create = source.get("create", create)
                 use_glob = source.get("glob", use_glob)
                 base_prefix = source.get("prefix", base_prefix)
@@ -84,6 +87,7 @@ class Link(Plugin):
                             relative,
                             canonical_path,
                             force,
+                            backup_root,
                         )
                     success &= self._link(
                         glob_full_item,
@@ -106,7 +110,9 @@ class Link(Plugin):
                     self._log.warning("Nonexistent source %s -> %s" % (destination, path))
                     continue
                 if force or relink:
-                    success &= self._delete(path, destination, relative, canonical_path, force)
+                    success &= self._delete(
+                        path, destination, relative, canonical_path, force, backup_root
+                    )
                 success &= self._link(path, destination, relative, canonical_path, ignore_missing)
         if success:
             self._log.info("All links have been set up")
@@ -120,6 +126,48 @@ class Link(Plugin):
             self._log.debug("Test '%s' returned false" % command)
         return ret == 0
 
+    def _backup(self, link_name, backup_root):
+        if not backup_root:
+            return False
+        success = True
+        source = os.path.expanduser(link_name)
+        timestamp = datetime.datetime.now().strftime(".%Y%m%dT%H%M%S.%f")
+        backup_root = os.path.expandvars(os.path.expanduser(backup_root))
+        backup_root = os.path.normpath(os.path.join(self._context.base_directory(), backup_root))
+        destination, ext = os.path.splitext(
+            os.path.normpath(os.path.splitdrive(source)[1]).strip("/")
+        )
+        destination = os.path.join(backup_root, destination + timestamp + ext)
+        success &= self._create(destination)
+        if os.path.islink(source):
+            try:
+                shutil.copy2(source, destination, follow_symlinks=False)
+            except OSError:
+                self._log.warning("Failed to backup symlink %s to %s" % (source, destination))
+                success = False
+            else:
+                self._log.lowinfo("Performed backup of symlink %s to %s" % (source, destination))
+        elif os.path.isdir(source):
+            try:
+                shutil.copytree(source, destination, symlinks=True)
+            except OSError:
+                self._log.warning("Failed to backup directory %s to %s" % (source, destination))
+                success = False
+            else:
+                self._log.lowinfo("performed backup of directory %s to %s" % (source, destination))
+        elif os.path.isfile(source):
+            try:
+                shutil.copy2(source, destination)
+            except OSError:
+                self._log.warning("Failed to backup file %s to %s" % (source, destination))
+                success = False
+            else:
+                self._log.lowinfo("Performed backup of file %s to %s" % (source, destination))
+        else:
+            self._log.warning("Failed to backup irregular file %s" % source)
+            success = False
+        return success
+
     def _default_source(self, destination, source):
         if source is None:
             basename = os.path.basename(destination)
@@ -203,7 +251,7 @@ class Link(Plugin):
                 self._log.lowinfo("Creating directory %s" % parent)
         return success
 
-    def _delete(self, source, path, relative, canonical_path, force):
+    def _delete(self, source, path, relative, canonical_path, force, backup_root):
         success = True
         source = os.path.join(self._context.base_directory(canonical_path=canonical_path), source)
         fullpath = os.path.abspath(os.path.expanduser(path))
@@ -213,8 +261,13 @@ class Link(Plugin):
             self._exists(path) and not self._is_link(path)
         ):
             removed = False
+            if backup_root:
+                backed_up = self._backup(path, backup_root)
             try:
-                if os.path.islink(fullpath):
+                if backup_root and not backed_up:
+                    self._log.warning("Skipping removal of %s due to failed backup" % path)
+                    success = False
+                elif os.path.islink(fullpath):
                     os.unlink(fullpath)
                     removed = True
                 elif force:

tests/test_link.py

@@ -175,6 +175,149 @@ def test_link_force_overwrite_symlink(home, dotfiles, run_dotbot):
     assert os.path.isfile(os.path.join(home, ".dir", "f"))
 
 
+def test_link_force_overwrite_source(home, dotfiles, run_dotbot):
+    """Verify force overwrites a symlinked directory."""
+
+    os.symlink(home, os.path.join(home, ".link"))
+    with open(os.path.join(home, "file"), "w") as file:
+        file.write("")
+    os.mkdir(os.path.join(home, "dir"))
+    dotfiles.write("dir/f")
+
+    config = [
+        {
+            "link": {
+                "~/.link": {"path": "dir", "force": True},
+                "~/file": {"path": "dir", "force": True},
+                "~/dir": {"path": "dir", "force": True},
+            }
+        }
+    ]
+    dotfiles.write_config(config)
+    run_dotbot()
+
+    assert os.path.isfile(os.path.join(home, ".link", "f"))
+    assert os.path.isfile(os.path.join(home, "file", "f"))
+    assert os.path.isfile(os.path.join(home, "dir", "f"))
+
+
+def test_backup_mirrors_absolute_path(home, dotfiles, run_dotbot):
+    """Verify backup path from backup dir is same as original path from root."""
+
+    os.symlink(home, os.path.join(home, ".f"))
+    dotfiles.write("f")
+
+    backup_root = os.path.join(dotfiles.directory, "backup")
+    config = [{"link": {"~/.f": {"path": "f", "force": True, "backup-root": backup_root}}}]
+    dotfiles.write_config(config)
+    run_dotbot()
+
+    assert os.path.isdir(os.path.join(backup_root, home[1:]))
+
+
+def test_link_force_backups_source(home, dotfiles, run_dotbot):
+    """Verify force backups a symlinked directory."""
+
+    os.symlink(home, os.path.join(home, ".link"))
+    with open(os.path.join(home, "file"), "w") as file:
+        file.write("apple")
+    os.mkdir(os.path.join(home, "dir"))
+    dotfiles.write("dir/f", "peach")
+
+    backup_root = os.path.join(dotfiles.directory, "backup")
+    config = [
+        {
+            "link": {
+                "~/.link": {"path": "dir", "force": True, "backup-root": backup_root},
+                "~/file": {"path": "dir", "force": True, "backup-root": backup_root},
+                "~/dir": {"path": "dir", "force": True, "backup-root": backup_root},
+            }
+        }
+    ]
+    dotfiles.write_config(config)
+    run_dotbot()
+
+    backup_home = os.path.join(backup_root, home[1:])
+    dir_items = os.listdir(backup_home)
+    test_items = (".link", "file", "dir")
+    backuped = {
+        test_item: dir_item
+        for dir_item in dir_items
+        for test_item in test_items
+        if test_item in dir_item
+    }
+
+    assert set(backuped.keys()) == set(test_items)
+    assert os.path.islink(os.path.join(backup_home, backuped[".link"]))
+    assert home in os.readlink(os.path.join(backup_home, backuped[".link"]))
+    assert os.path.isfile(os.path.join(backup_home, backuped["file"]))
+    with open(os.path.join(backup_home, backuped["file"])) as file:
+        assert file.read() == "apple"
+    assert os.path.isdir(os.path.join(backup_home, backuped["dir"]))
+    for link in test_items:
+        with open(os.path.join(home, link, "f")) as file:
+            assert file.read() == "peach"
+
+
+def test_link_force_aborts_on_failed_backup(home, dotfiles, run_dotbot):
+    """Verify force is aborted if backup fails."""
+
+    os.symlink(home, os.path.join(home, ".link"))
+    with open(os.path.join(home, "file"), "w") as file:
+        file.write("apple")
+    os.mkdir(os.path.join(home, "dir"))
+    dotfiles.write("backup")
+    dotfiles.write("dir/f")
+
+    backup_root = os.path.join(dotfiles.directory, "backup")
+    config = [
+        {
+            "link": {
+                "~/.link": {"path": "dir", "force": True, "backup-root": backup_root},
+                "~/file": {"path": "dir", "force": True, "backup-root": backup_root},
+                "~/dir": {"path": "dir", "force": True, "backup-root": backup_root},
+            }
+        }
+    ]
+    dotfiles.write_config(config)
+    with pytest.raises(SystemExit):
+        run_dotbot()
+
+    assert os.path.islink(os.path.join(home, ".link"))
+    assert home in os.readlink(os.path.join(home, ".link"))
+    assert os.path.isfile(os.path.join(home, "file"))
+    with open(os.path.join(home, "file")) as file:
+        assert file.read() == "apple"
+    assert os.path.isdir(os.path.join(home, "dir"))
+
+
+def test_no_backup_when_no_force_relink(home, dotfiles, run_dotbot):
+    """Verify backup is a no-op without an accompanying force or relink."""
+
+    os.symlink(home, os.path.join(home, ".link"))
+    with open(os.path.join(home, "file"), "w") as file:
+        file.write("apple")
+    os.mkdir(os.path.join(home, "dir"))
+    dotfiles.write("dir/f")
+
+    backup_root = os.path.join(dotfiles.directory, "backup")
+    config = [
+        {
+            "link": {
+                "~/.link": {"path": "dir", "backup-root": backup_root},
+                "~/file": {"path": "dir", "backup-root": backup_root},
+                "~/dir": {"path": "dir", "backup-root": backup_root},
+                "~/.new": {"path": "dir", "backup-root": backup_root},
+            }
+        }
+    ]
+    dotfiles.write_config(config)
+    with pytest.raises(SystemExit):
+        run_dotbot()
+
+    assert not os.path.exists(backup_root)
+
+
 def test_link_glob_1(home, dotfiles, run_dotbot):
     """Verify globbing works."""
 
@@ -909,6 +1052,80 @@ def test_link_relink_overwrite_symlink(home, dotfiles, run_dotbot):
         assert file.read() == "apple"
 
 
+def test_link_relink_backups_symlink(home, dotfiles, run_dotbot):
+    """Verify relink backups symlinks."""
+
+    dotfiles.write("f", "apple")
+    with open(os.path.join(home, "f"), "w") as file:
+        file.write("grape")
+    os.symlink(os.path.join(home, "f"), os.path.join(home, ".f"))
+
+    backup_root = os.path.join(dotfiles.directory, "backup")
+    dotfiles.write_config(
+        [{"link": {"~/.f": {"path": "f", "relink": True, "backup-root": backup_root}}}]
+    )
+    run_dotbot()
+
+    backup_home = os.path.join(backup_root, home[1:])
+    assert os.path.isdir(backup_home)
+    dir_items = os.listdir(backup_home)
+    assert len(dir_items) == 1
+    backuped = os.path.join(backup_home, dir_items[0])
+    assert os.path.islink(backuped)
+    with open(backuped, "r") as file:
+        assert file.read() == "grape"
+    with open(os.path.join(home, ".f"), "r") as file:
+        assert file.read() == "apple"
+
+
+def test_link_relink_aborts_on_failed_backup(home, dotfiles, run_dotbot):
+    """Verify relink is aborted if backup fails."""
+
+    dotfiles.write("f", "apple")
+    with open(os.path.join(home, "f"), "w") as file:
+        file.write("grape")
+    os.symlink(os.path.join(home, "f"), os.path.join(home, ".f"))
+    dotfiles.write("backup")
+
+    backup_root = os.path.join(dotfiles.directory, "backup")
+    dotfiles.write_config(
+        [{"link": {"~/.f": {"path": "f", "relink": True, "backup-root": backup_root}}}]
+    )
+    with pytest.raises(SystemExit):
+        run_dotbot()
+
+    with open(os.path.join(home, ".f"), "r") as file:
+        assert file.read() == "grape"
+
+
+def test_backup_is_sequentially_differetiated(home, dotfiles, run_dotbot):
+    """Verify that backups do not overwrite each other and get sequentially different names."""
+
+    with open(os.path.join(home, "f"), "w") as file:
+        file.write("grape")
+    os.symlink(os.path.join(home, "f"), os.path.join(home, ".f"))
+    dotfiles.write("f", "apple")
+    dotfiles.write("dir/f", "peach")
+
+    backup_root = os.path.join(dotfiles.directory, "backup")
+    dotfiles.write_config(
+        [
+            {"link": {"~/.f": {"path": "f", "relink": True, "backup-root": backup_root}}},
+            {"link": {"~/.f": {"path": "dir/f", "relink": True, "backup-root": backup_root}}},
+        ]
+    )
+    run_dotbot()
+
+    backup_home = os.path.join(backup_root, home[1:])
+    dir_items = sorted(os.listdir(backup_home))
+    with open(os.path.join(backup_home, dir_items[0])) as file:
+        assert file.read() == "grape"
+    with open(os.path.join(backup_home, dir_items[1])) as file:
+        assert file.read() == "apple"
+    with open(os.path.join(home, ".f"), "r") as file:
+        assert file.read() == "peach"
+
+
 def test_link_relink_relative_leaves_file(home, dotfiles, run_dotbot):
     """Verify relink relative does not incorrectly relink file."""