migration-guard

title	migration-guard
name	migration-guard
description	Review database migration files for naming conventions and dangerous operations. Auto-activates for migration files.
paths	["migrations/**","*.sql","db/migrate/**"]

Migration review

Review the current migration file for naming conventions, rollback presence, and dangerous operations.

Step 1: Identify the file being reviewed

Use the current file context to determine which migration file is being worked on. If the user specified a file path, use that. If the context is ambiguous, ask the user which file to review before proceeding.

Step 2: Check the file name

Extract the file name (not the full path) and check it against two accepted naming formats:

Format A — Timestamp prefix: Pattern: YYYYMMDDHHMMSS_description.sql Example: 20260513143207_add_user_roles.sql

• Year: 4 digits
• Month: 2 digits (01–12)
• Day: 2 digits (01–31)
• Hour: 2 digits (00–23)
• Minute: 2 digits (00–59)
• Second: 2 digits (00–59)
• Underscore separator
• Description: lowercase letters, digits, underscores
• Extension: .sql

Format B — Sequential prefix: Pattern: NNNN_description.sql Example: 0042_add_user_roles.sql

• Number: 1 or more digits, typically zero-padded to 4 digits
• Underscore separator
• Description: lowercase letters, digits, underscores
• Extension: .sql

If the file name matches neither format, mark the naming check as FAIL and note the reason.

Step 3: Check for rollback

Read the file content and look for either:

• A clearly labeled rollback section (a comment like -- rollback, -- down, -- revert, followed by SQL that undoes the migration)
• A comment explicitly marking it as irreversible (e.g., -- This migration is irreversible, -- no rollback)

If neither is present, mark rollback as NO.

Step 4: Check for dangerous operations

Read the file and scan for these patterns (case-insensitive):

• DROP TABLE without IF EXISTS immediately following — flag as WARNING
• DROP TABLE IF EXISTS — acceptable, no warning
• DELETE FROM without a WHERE clause on the same or next line — flag as WARNING
• UPDATE without a WHERE clause on the same or next line — flag as WARNING
• TRUNCATE on any table — flag as WARNING (destructive, often irreversible in production)
• DROP COLUMN — flag as NOTICE (may break dependent code; not always dangerous but requires attention)

For each match, note the line number.

Step 5: Output the checklist

Present findings in this format:

Migration review: <filename>

Naming convention: PASS
  - Format: timestamp-prefix / sequential-prefix
  
  (or)
  
Naming convention: FAIL
  - Reason: <specific reason>

Rollback: YES / NO / MARKED IRREVERSIBLE
  - <brief note on what the rollback does, or why it is marked irreversible>

Dangerous operations: NONE
  
  (or)
  
Dangerous operations:
  WARNING line 14: DELETE without WHERE clause
  WARNING line 22: TRUNCATE on orders table
  NOTICE  line 31: DROP COLUMN — confirm no dependent code references this column

Do not modify the migration file. This skill reviews only.