refactor(url): reversible SSH-style URL patch

why:
- Previously, enabling SSH-style URL detection mutated libvcs’s DEFAULT_RULES on import and lost the rule’s original metadata.
- Users couldn’t cleanly disable the patch or restore upstream defaults if libvcs changed.
- Implicit module-import side-effects are harder to reason about.

what:
- Introduce private `_orig_rule_meta` to snapshot rule’s original metadata.
- Store original metadata on first enable and apply `(True, 100)`.
- Restore saved metadata (or safe defaults) on disable, clearing snapshot.
- Remove auto-patch on import; require explicit call.
- Add `ssh_style_url_detection` context manager.
- Call `enable_ssh_style_url_detection()` in `update_repo()` to maintain behavior.
- Add pytest tests for enable/disable roundtrip and context manager.

Author: tony

src/vcspull/cli/sync.py

@@ -12,6 +12,7 @@
 
 from vcspull import exc
 from vcspull.config import filter_repos, find_config_files, load_configs
+from vcspull.url import enable_ssh_style_url_detection
 
 if t.TYPE_CHECKING:
     import argparse
@@ -147,6 +148,8 @@ def update_repo(
     # repo_dict: Dict[str, Union[str, Dict[str, GitRemote], pathlib.Path]]
 ) -> GitSync:
     """Synchronize a single repository."""
+    # Ensure SSH-style URLs are recognized as explicit Git URLs
+    enable_ssh_style_url_detection()
     repo_dict = deepcopy(repo_dict)
     if "pip_url" not in repo_dict:
         repo_dict["pip_url"] = repo_dict.pop("url")

src/vcspull/url.py

@@ -2,16 +2,21 @@
 
 from __future__ import annotations
 
+from typing import Any
+
 from libvcs.url.git import DEFAULT_RULES
 
+_orig_rule_meta: dict[str, tuple[bool, int]] = {}
+
 
 def enable_ssh_style_url_detection() -> None:
     """Enable detection of SSH-style URLs as explicit Git URLs.
 
     This makes the core-git-scp rule explicit, which allows URLs like
     'user@hostname:path/to/repo.git' to be detected with is_explicit=True.
 
-    Examples:
+    Examples
+    --------
         >>> from vcspull.url import enable_ssh_style_url_detection
         >>> from libvcs.url.git import GitURL
         >>> # Without the patch
@@ -22,12 +27,14 @@ def enable_ssh_style_url_detection() -> None:
         >>> GitURL.is_valid('user@hostname:path/to/repo.git', is_explicit=True)
         True
     """
+    # Patch the core-git-scp rule, storing its original state if not already stored
     for rule in DEFAULT_RULES:
         if rule.label == "core-git-scp":
-            # Make the rule explicit so it can be detected with is_explicit=True
+            if rule.label not in _orig_rule_meta:
+                _orig_rule_meta[rule.label] = (rule.is_explicit, rule.weight)
             rule.is_explicit = True
-            # Increase the weight to ensure it takes precedence
             rule.weight = 100
+            break
 
 
 def disable_ssh_style_url_detection() -> None:
@@ -36,8 +43,10 @@ def disable_ssh_style_url_detection() -> None:
     This reverts the core-git-scp rule to its original state, where URLs like
     'user@hostname:path/to/repo.git' are not detected with is_explicit=True.
 
-    Examples:
-        >>> from vcspull.url import enable_ssh_style_url_detection, disable_ssh_style_url_detection
+    Examples
+    --------
+        >>> from vcspull.url import enable_ssh_style_url_detection
+        >>> from vcspull.url import disable_ssh_style_url_detection
         >>> from libvcs.url.git import GitURL
         >>> # Enable the patch
         >>> enable_ssh_style_url_detection()
@@ -48,17 +57,25 @@ def disable_ssh_style_url_detection() -> None:
         >>> GitURL.is_valid('user@hostname:path/to/repo.git', is_explicit=True)
         False
     """
+    # Restore the core-git-scp rule to its original state, if known
     for rule in DEFAULT_RULES:
         if rule.label == "core-git-scp":
-            # Revert to original state
-            rule.is_explicit = False
-            rule.weight = 0
+            orig = _orig_rule_meta.get(rule.label)
+            if orig:
+                rule.is_explicit, rule.weight = orig
+                _orig_rule_meta.pop(rule.label, None)
+            else:
+                # Fallback to safe defaults
+                rule.is_explicit = False
+                rule.weight = 0
+            break
 
 
 def is_ssh_style_url_detection_enabled() -> bool:
     """Check if SSH-style URL detection is enabled.
 
-    Returns:
+    Returns
+    -------
         bool: True if SSH-style URL detection is enabled, False otherwise.
     """
     for rule in DEFAULT_RULES:
@@ -67,5 +84,30 @@ def is_ssh_style_url_detection_enabled() -> bool:
     return False
 
 
-# Enable SSH-style URL detection by default
-enable_ssh_style_url_detection()
+"""
+Context manager and utility for SSH-style URL detection.
+"""
+
+
+class ssh_style_url_detection:
+    """Context manager to enable/disable SSH-style URL detection."""
+
+    def __init__(self, enabled: bool = True) -> None:
+        self.enabled = enabled
+
+    def __enter__(self) -> None:
+        """Enable or disable SSH-style URL detection on context enter."""
+        if self.enabled:
+            enable_ssh_style_url_detection()
+        else:
+            disable_ssh_style_url_detection()
+
+    def __exit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: Any,
+    ) -> None:
+        """Restore original SSH-style URL detection state on context exit."""
+        # Always restore to disabled after context
+        disable_ssh_style_url_detection()

tests/test_url.py

@@ -3,9 +3,13 @@
 from __future__ import annotations
 
 import pytest
-from libvcs.url.git import GitURL
+from libvcs.url.git import DEFAULT_RULES, GitURL
 
-from vcspull.url import disable_ssh_style_url_detection, enable_ssh_style_url_detection
+from vcspull.url import (
+    disable_ssh_style_url_detection,
+    enable_ssh_style_url_detection,
+    ssh_style_url_detection,
+)
 
 
 def test_ssh_style_url_detection_toggle() -> None:
@@ -17,14 +21,18 @@ def test_ssh_style_url_detection_toggle() -> None:
 
     # Without the patch, SSH-style URLs should not be detected as explicit
     assert GitURL.is_valid(url)  # Should be valid in non-explicit mode
-    assert not GitURL.is_valid(url, is_explicit=True)  # Should not be valid in explicit mode
+    assert not GitURL.is_valid(
+        url, is_explicit=True
+    )  # Should not be valid in explicit mode
 
     # Now enable the detection
     enable_ssh_style_url_detection()
 
     # With the patch, SSH-style URLs should be detected as explicit
     assert GitURL.is_valid(url)  # Should still be valid in non-explicit mode
-    assert GitURL.is_valid(url, is_explicit=True)  # Should now be valid in explicit mode
+    assert GitURL.is_valid(
+        url, is_explicit=True
+    )  # Should now be valid in explicit mode
 
     # Verify the rule used
     git_url = GitURL(url)
@@ -95,3 +103,39 @@ def test_ssh_style_url_parsing(
     assert git_url.hostname == expected_hostname
     assert git_url.path == expected_path
     assert git_url.suffix == ".git"
+
+
+def test_enable_disable_restores_original_state() -> None:
+    """Original rule metadata is preserved and restored after enable/disable."""
+    # Ensure any prior patch is cleared
+    disable_ssh_style_url_detection()
+    # Find the core-git-scp rule and capture its original state
+    rule = next(r for r in DEFAULT_RULES if r.label == "core-git-scp")
+    orig_state = (rule.is_explicit, rule.weight)
+
+    # Disabling without prior enable should leave original state
+    disable_ssh_style_url_detection()
+    assert (rule.is_explicit, rule.weight) == orig_state
+
+    # Enable should patch
+    enable_ssh_style_url_detection()
+    assert rule.is_explicit is True
+    assert rule.weight == 100
+
+    # Disable should restore to original
+    disable_ssh_style_url_detection()
+    assert (rule.is_explicit, rule.weight) == orig_state
+
+
+def test_context_manager_restores_original_state() -> None:
+    """Context manager enables then restores original rule state."""
+    rule = next(r for r in DEFAULT_RULES if r.label == "core-git-scp")
+    orig_state = (rule.is_explicit, rule.weight)
+
+    # Use context manager
+    with ssh_style_url_detection():
+        assert rule.is_explicit is True
+        assert rule.weight == 100
+
+    # After context, state should be back to original
+    assert (rule.is_explicit, rule.weight) == orig_state