One Big Mistake in Batch Renaming Tools: Skipping Dry-Run and Rollback

One Big Mistake in Batch Renamers

The biggest trust breaker in file renaming tools is simple: users click apply and discover they cannot recover a bad pattern. Dry-run and rollback are not “nice to have.” They are core safety features.

Step 1: Compile rename plan before writing anything

from dataclasses import dataclass

@dataclass
class RenameOp:
    src: str
    dst: str


def plan_ops(files, transform):
    return [RenameOp(src=f, dst=transform(f)) for f in files]

Step 2: Validate collisions and invalid targets

def validate_ops(ops):
    targets = [op.dst for op in ops]
    if len(targets) != len(set(targets)):
        raise ValueError("target collision detected")
    if any(not t.strip() for t in targets):
        raise ValueError("empty filename target")

Step 3: Write rollback journal on execute

[
  {"src": "raw-001.png", "dst": "cover-001.png"},
  {"src": "raw-002.png", "dst": "cover-002.png"}
]

Pitfalls

• Executing rename operations without preview mode.
• No rollback artifact for partial failures.
• Path normalization not handled across platforms.

Verification

• Dry-run preview exactly matches executed operations.
• Rollback restores original names after simulated crash.
• Collision checks block unsafe patterns.