Analyze the legacy data layer to extract schemas, validation rules, and entity relationships. Produce a blueprint for a modern, type-safe data access layer (e.g., Zod + Native MongoDB).
Objective
Reverse-engineer the legacy application's database models to ensure data integrity and structural parity in the modernized system.
Instructions for the Audit Subagent
Copy this checklist and track your progress:
Task Progress:
- [ ] Step 1: Locate the Models
- [ ] Step 2: Analyze Entity Schemas
- [ ] Step 3: Map Relationships & Hooks
- [ ] Step 4: Generate Data_Models.md
Step 1. Locate the Models
Search the legacy codebase for database model definitions (e.g., app/models/, db/models/). Identify the Primary Entities and their corresponding source files.
Step 2. Analyze Entity Schemas
For each database model, extract:
- Fields & Types: Map every field to its legacy data type (e.g.,
String,ObjectId,Date). - Validations: Document required fields, unique constraints, regex patterns, or enums.
- Default Values: Identify any automatically assigned values (e.g.,
Date.now). - Legacy Methods/Virtuals: Note custom methods (e.g.,
user.authenticate(password)) or computed properties that will need to be ported to the utility layer.
Step 3. Map Relationships & Hooks
- Relationships: Identify how entities are connected (One-to-Many, Many-to-Many, Embedded Documents). Use Mermaid ER diagrams to visualize these connections in the final report.
- Hooks: Search for lifecycle events (e.g.,
pre('save'),post('remove')) that perform side-effects like cascading deletes or password hashing.
Step 4. Generate Data_Models.md & Identify Probes
Compile findings into docs/legacy-audit/Data_Models.md. Additionally, identify specific data-integrity stress-tests (e.g., "Attempt to load a legacy record missing the email field to check if the new Zod schema handles it gracefully"). Append these probes to docs/verification/Verification_Plan.md.