Lecture on Zod Validation Library

Introduction

• Speaker: Kyle
• Platform: Web Dev Simplified
• Purpose: Simplify usage of Zod, a popular TypeScript-first schema validation library.
• Features of Zod:
  • Zero dependencies
  • Small library size
  • Immutable-first design
  • Supports functional programming style
  • Excellent TypeScript support
  • Usable in plain JavaScript scenarios

Getting Started with Zod

• Installation:
  • Use command npm i zod to install
  • Import using import Z from 'zod'
  • Ensure TypeScript strict mode is true

Example Usage

• Creating a Schema:
  • Use Z.object() to define an object schema
  • Define data types like strings, numbers, booleans
• Validation:
  • Use schema.parse(data) to validate
  • Error handling if data does not match schema

Advanced TypeScript Integration

• Inferred Types:
  • Use Z.infer() to infer TypeScript types from the schema
• Safe Parsing:
  • Use safeParse() for boolean success/failure

Zod Primitive Types

• Common Types:
  • String, Number, Boolean, BigInt, Date
  • Optional values with .optional()
• Special Types:
  • Undefined, Null, Void, Any, Unknown, Never

Advanced Validations

• String:
  • .min(), .max(), .email(), .url() validations
• Number:
  • .gt(value), .lt(value) for ranges
• Optional and Default Values:
  • Use .optional(), .nullable(), .nullish()
  • Define default values with .default(value)

Object and Array Types

• Object Handling:
  • Get shapes with .shape
  • Use .partial(), .pick(), .omit(), .extend(), .merge()
  • Control unknown keys with .passthrough(), .strict()
• Array Handling:
  • Define using Z.array(elementType)
  • Use .nonempty(), .min(length), .max(length)

Advanced Data Structures

• Tuples:
  • Fixed-length array with specific types
  • Use .rest() for additional types
• Union and Discriminated Union:
  • Define types using Z.union([]) or Z.discriminatedUnion()
• Record and Map:
  • Use Z.record(keyType, valueType)
  • Maps: Z.map(keyType, valueType)

Sets and Promises

• Set Type:
  • Unique array elements
  • Similar methods to arrays
• Promise Type:
  • Ensure a promise structure and its return type

Custom Validation

• Refine Method:
  • Use refine() to add custom validation logic
  • Use superRefine() for advanced control

Error Handling

• Error Messages:
  • Customize using error map and type errors
  • Use zod-validation-error package for simplified error messages

Conclusion

• Zod is a powerful library for TypeScript development
• Provides comprehensive validation tools
• Integrates deeply with TypeScript for type-safe code
• Recommended to use additional libraries for better error message handling

Kyle emphasizes Zod's flexibility and its strong integration with TypeScript, making it a valuable tool for developers aiming for robust validation in web applications.