spinder-type-creation

name	spinder-type-creation
description	Create new Zod-based type definitions for the Spinder expense tracking app, following the project's type organization patterns.

Spinder Type Creation Skill

This skill helps create new type definitions using Zod for the Spinder application, ensuring type safety and validation throughout the codebase.

When to Use

Use this skill when you need to:

• Define new data structures for transactions, buckets, or other domain objects
• Add validation schemas for API responses or user inputs
• Extend existing types with additional properties
• Create shared types that can be used by both client and server code

Type Organization

All types must be created following these rules:

• Types are defined in src/shared/type.<type-name>.ts
• Use Zod schemas for validation and TypeScript type inference
• Group related types within the same file
• Export both the schema and the inferred type
• Use descriptive names that reflect the domain

Steps to Create a Type

1. Create the type file at src/shared/type.<type-name>.ts
2. Import Zod and define the schema
3. Use appropriate Zod validators (z.string(), z.number(), z.object(), etc.)
4. Add optional fields with .optional() when applicable
5. Define nested objects using z.object()
6. Export the schema and the inferred type
7. Import and use the type in components, providers, and utilities

Example Type Definition

import { z } from "zod";

export const ExampleType = z.object({
  id: z.string(),
  name: z.string().min(1, "Name is required"),
  amount: z.number().positive("Amount must be positive"),
  category: z.enum(["income", "expense", "transfer"]),
  date: z.string().regex(/^\d{4}-\d{2}-\d{2}$/, "Invalid date format"),
  tags: z.array(z.string()).optional(),
});

export type ExampleType = z.infer<typeof ExampleType>;

Zod Best Practices

• Use specific validators: .email(), .url(), .uuid(), etc.
• Add custom error messages with the second parameter
• Use .transform() for data conversion
• Combine schemas with .and(), .or(), .merge()
• Use .refine() for complex validation logic
• Make fields optional with .optional() or .nullable()

Type Usage

Once defined, import and use types in:

• Component properties and state
• Context definitions
• Utility functions
• Event payloads
• Provider data structures

Validation

• Types are validated at runtime using Zod's parse() or safeParse()
• Use safeParse() in user-facing code to handle validation errors gracefully
• Log or display validation errors to help with debugging

Related Files

• Existing Types - Examples of current type definitions
• Zod Documentation - Complete Zod API reference
• Type Validation - How to validate data with types