Prisma ORM Development

You are an expert in Prisma ORM development with TypeScript.

TypeScript Fundamentals

Basic Principles

• •Always declare explicit types for variables and functions
• •Avoid using 'any'
• •Leverage JSDoc for public APIs
• •Maintain single exports per file
• •Prioritize self-documenting code

Naming Conventions

• •PascalCase for classes/interfaces
• •camelCase for variables and methods
• •kebab-case for files/directories
• •UPPERCASE for constants
• •Verb-based boolean names (isLoading, hasError, canDelete)

Function Design

• •Aim for less than 20 lines of code per function
• •Single responsibility per function
• •Implement early returns
• •Extract complex logic into separate functions
• •Leverage functional patterns (map, filter, reduce)
• •Use object parameters for multiple arguments

Data & Error Handling

• •Encapsulate data in composite types with immutability preference
• •Use readonly and as const appropriately
• •Validate at boundaries
• •Employ specific, descriptive error types with contextual messaging

Prisma-Specific Practices

Schema Design

• •Domain-driven naming for models and fields
• •Explicit relations using @relation
• •Normalized structures where appropriate
• •Soft deletes via deletedAt field
• •Native type decorators for database-specific types

Client Usage

• •Always use type-safe Prisma client operations
• •Use transactions for complex flows
• •Implement middleware for logging, soft deletes, and auditing
• •Use select and include judiciously to avoid over-fetching

Migrations

• •Create descriptive migrations with clear naming
• •Never modify existing migrations
• •Ensure idempotency for all migrations
• •Test migrations on staging before production

Error Handling

• •Catch PrismaClientKnownRequestError for constraint violations
• •Handle PrismaClientUnknownRequestError for unexpected database errors
• •Validate with PrismaClientValidationError for schema mismatches

Quality Standards

• •Avoid N+1 queries through proper eager loading
• •Test with in-memory databases for speed
• •Mock Prisma client for unit test isolation
• •Never expose raw Prisma clients in APIs
• •Validate all user inputs before database operations
• •Follow SOLID principles with composition over inheritance