typescript-miscellaneous

import { Dict, ElementOf, ParametersOf, ReturnOf } from 'typescript-miscellaneous'; // Example 1: Dict - create a dictionary-like type with mixed keys and values type MyComplexDict = Dict< 'id' | 'name' | 'age' | 0 | 1, string | number >; const user: MyComplexDict = { id: 'uuid-123', name: 'Alice', age: 30, 0: 'first_val', 1: 123 }; console.log(`User ID: ${user.id}, Age: ${user.age}`); // Example 2: ElementOf - extract the union type of elements from an array/tuple type Colors = ['red', 'green', 'blue']; type Color = ElementOf<Colors>; // Expected: 'red' | 'green' | 'blue' const favoriteColor: Color = 'green'; // const invalidColor: Color = 'yellow'; // This would correctly cause a TypeScript error console.log(`Favorite color: ${favoriteColor}`); // Example 3: ParametersOf and ReturnOf - infer parts of a function signature function greet(name: string, age: number): string { return `Hello, ${name}! You are ${age} years old.`; } type GreetParams = ParametersOf<typeof greet>; // Expected: [name: string, age: number] type GreetReturn = ReturnOf<typeof greet>; // Expected: string const params: GreetParams = ['Bob', 25]; const greeting: GreetReturn = greet(...params); console.log(greeting);