core/tools: soft-confirm file overwrite only, not partial edits

src/plyngent/tools/danger.py

@@ -110,36 +110,37 @@ def _shell_or_dash_c_reason(argv: Sequence[str], *, via: str) -> str | None:
 
 
 def _write_file_reason(args: Mapping[str, object]) -> str | None:
+    """Confirm only when write_file would replace an existing file."""
     path = args.get("path")
     if not isinstance(path, str) or not path:
         return None
     try:
         target = resolve_path(path)
     except WorkspaceError:
-        return f"write file {path!r}"
-    return f"write file {path!r} ({target})"
-
-
-def _edit_replace_reason(args: Mapping[str, object]) -> str | None:
-    path = args.get("path")
-    if not isinstance(path, str) or not path:
+        # Path policy will fail later; no soft-confirm without a resolved target.
         return None
-    return f"edit (replace) in {path!r}"
-
-
-def _edit_lineno_reason(args: Mapping[str, object]) -> str | None:
-    path = args.get("path")
-    if not isinstance(path, str) or not path:
-        return None
-    start = args.get("start_line")
-    end = args.get("end_line")
-    return f"edit lines {start}-{end} in {path!r}"
+    if target.is_file():
+        return f"overwrite existing file {path!r} ({target})"
+    # New file or directory path: no total-overwrite risk for soft-confirm.
+    return None
 
 
 def _copy_path_reason(args: Mapping[str, object]) -> str | None:
+    """Confirm copy only when it would replace an existing destination path."""
     src = args.get("src")
     dst = args.get("dst")
-    return f"copy {src!r} → {dst!r}"
+    overwrite = bool(args.get("overwrite", False))
+    if not overwrite:
+        return None
+    if not isinstance(dst, str) or not dst:
+        return f"copy {src!r} → {dst!r} (overwrite)"
+    try:
+        target = resolve_path(dst)
+    except WorkspaceError:
+        return None
+    if target.exists():
+        return f"copy {src!r} → overwrite existing {dst!r} ({target})"
+    return None
 
 
 def _move_path_reason(args: Mapping[str, object]) -> str | None:
@@ -222,10 +223,6 @@ def classify_danger(name: str, args: Mapping[str, object]) -> str | None:  # noq
         return _copy_path_reason(args)
     if name == "write_file":
         return _write_file_reason(args)
-    if name == "edit_replace":
-        return _edit_replace_reason(args)
-    if name == "edit_lineno":
-        return _edit_lineno_reason(args)
     if name == "run_command":
         return _run_command_reason(args)
     if name == "run_command_batch":

tests/test_tools/test_danger.py

@@ -12,18 +12,32 @@ def test_classify_delete_and_move() -> None:
 
 
 def test_classify_copy() -> None:
-    assert "copy" in (classify_danger("copy_path", {"src": "a", "dst": "b"}) or "")
+    # Without overwrite flag, copy is not soft-confirmed.
+    assert classify_danger("copy_path", {"src": "a", "dst": "b"}) is None
+    assert classify_danger(
+        "copy_path", {"src": "a", "dst": "b", "overwrite": False}
+    ) is None
 
 
-def test_classify_write_and_edits(tmp_path: Path) -> None:
+def test_classify_write_overwrite_only(tmp_path: Path) -> None:
     from plyngent.tools.workspace import clear_workspace_root, set_workspace_root
 
     set_workspace_root(tmp_path)
     try:
+        # New file: no soft-confirm
+        assert classify_danger("write_file", {"path": "new.txt"}) is None
+        # Partial edits: never soft-confirm
+        assert classify_danger("edit_replace", {"path": "x.txt"}) is None
+        assert classify_danger("edit_lineno", {"path": "x.txt", "start_line": 1, "end_line": 2}) is None
+        # Existing file write: confirm total overwrite
+        (tmp_path / "x.txt").write_text("old", encoding="utf-8")
         reason = classify_danger("write_file", {"path": "x.txt"})
-        assert reason is not None and "write file" in reason
-        assert "edit" in (classify_danger("edit_replace", {"path": "x.txt"}) or "")
-        assert "lines" in (classify_danger("edit_lineno", {"path": "x.txt", "start_line": 1, "end_line": 2}) or "")
+        assert reason is not None and "overwrite" in reason
+        (tmp_path / "dst.txt").write_text("d", encoding="utf-8")
+        (tmp_path / "src.txt").write_text("s", encoding="utf-8")
+        assert classify_danger("copy_path", {"src": "src.txt", "dst": "dst.txt", "overwrite": False}) is None
+        creason = classify_danger("copy_path", {"src": "src.txt", "dst": "dst.txt", "overwrite": True})
+        assert creason is not None and "overwrite" in creason
     finally:
         clear_workspace_root()