Prisma ORM Best Practices for TypeScript: Essential Cursor Rules Guide

Follow these numbered best practices for Prisma ORM in TypeScript to ensure clean, efficient, and maintainable code:

1. **Adopt Strict Typing Standards**: Define explicit types for all variables, functions, and parameters. Steer clear of 'any' type; instead, craft detailed interfaces and types. Document public APIs with JSDoc and limit files to one primary export for clarity.

2. **Follow Consistent Naming Conventions**: Employ PascalCase for types and interfaces, camelCase for variables and methods, kebab-case for files/folders, and UPPER_SNAKE_CASE for constants and env vars. Prefix booleans with 'is', 'has', or 'can', use full words, and start functions with action verbs.

3. **Craft Focused Functions**: Keep functions under 20 lines, dedicated to one task. Use descriptive verb-led names, early returns, and extract sub-logic into helpers. Favor array methods like map/filter/reduce, arrow functions for brevity, and object params over long arg lists.

4. **Prioritize Immutable Data Structures**: Wrap data in custom types, mark unchanging props as readonly, use 'as const' for literals, and validate inputs at entry points to maintain data integrity.

5. **Implement Robust Error Management**: Define custom error classes with rich context. Catch Prisma errors like PrismaClientKnownRequestError specifically, log with details, and translate to user-friendly messages while using global handlers.

6. **Design Domain-Centric Schemas**: Choose descriptive model names reflecting business domains. Apply @id, @unique, @relation decorators; normalize schemas; add deletedAt for soft deletes; and use native Prisma types for fields.

7. **Leverage Type-Safe Prisma Client**: Opt for transactions in multi-operation flows, middleware for logging/audits/soft deletes, explicit relation handling, and built-in filters/pagination to ensure safety and efficiency.

8. **Manage Migrations Effectively**: Generate named migrations for changes, review before deployment, avoid edits to committed ones, and design them to be repeatable.

9. **Test Comprehensively**: Employ in-memory DBs for units, mock clients for isolation, cover success/error/edge cases with factories, and add integration tests against real DBs.

10. **Boost Query Performance**: Select only needed fields with 'select/include', prevent N+1 issues, paginate via take/skip, use distinct, and profile queries regularly.

11. **Enforce Security Protocols**: Hide Prisma client from endpoints, validate/sanitize inputs, apply row-level security, and rely on Prisma's SQL injection safeguards.

12. **Organize Code Architecture**: Isolate data logic in repositories, inject Prisma dependencies, separate concerns, adhere to SOLID, and favor composition.

13. **Streamline Workflow**: Use Git for versioning, aim for high test coverage, integrate CI/CD, conduct peer reviews, and update deps routinely.