TypeScript Complete Guide

日本語版

TypeScript Complete Guide

TypeScript adds type safety to JavaScript, enabling large-scale development. This guide systematically covers everything in TypeScript -- from the depths of the type system, generics, and conditional types to Template Literal Types and type-level programming.

Target Audience

• Engineers who want to systematically learn TypeScript from the ground up
• Developers seeking a deep understanding of the type system
• Those who want to write type definitions for libraries and frameworks

Prerequisites

• Foundational knowledge of JavaScript (ES2022+)
• Basic familiarity with Node.js

Study Guide

00-basics -- TypeScript Basics

01-type-system -- Deep Dive into the Type System

02-advanced-types -- Advanced Type Patterns

03-patterns -- Practical Patterns

04-tooling -- Toolchain

Quick Reference

TypeScript Type Cheat Sheet:

  Utility Types:
    Partial<T>       -- Makes all properties optional
    Required<T>      -- Makes all properties required
    Readonly<T>      -- Makes all properties readonly
    Pick<T, K>       -- Extracts specified properties
    Omit<T, K>       -- Excludes specified properties
    Record<K, V>     -- Defines key and value types
    Extract<T, U>    -- Extracts types from T assignable to U
    Exclude<T, U>    -- Excludes types from T assignable to U
    ReturnType<F>    -- Return type of a function
    Parameters<F>    -- Parameter types of a function
    Awaited<T>       -- Resolved type of a Promise
    NonNullable<T>   -- Excludes null/​undefined

  Recommended tsconfig settings:
    "strict": true
    "noUncheckedIndexedAccess": true
    "exactOptionalPropertyTypes": true

References

1. TypeScript. "Handbook." typescriptlang.org/​docs, 2024.
2. Vanderkam, D. "Effective TypeScript." O'Reilly, 2024.
3. TypeScript. "Release Notes." typescriptlang.org/​docs/​handbook/​release-notes, 2024.