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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 | /** * Utility Types Library * * Common TypeScript utilities for the Elite Events application. * These types provide type-safe alternatives to common patterns. * * @example * ```tsx * import { Nullable, DeepReadonly, NonEmptyArray } from '@/types/utils'; * * type MaybeUser = Nullable<User>; * type ReadonlyConfig = DeepReadonly<Config>; * ``` */ // ============================================ // Nullability Utilities // ============================================ /** * Make a type nullable (can be null) */ export type Nullable<T> = T | null; /** * Make all properties optional and nullable */ export type NullablePartial<T> = { [P in keyof T]?: T[P] | null; }; /** * Make specific properties required while keeping others optional */ export type RequireFields<T, K extends keyof T> = Omit<T, K> & Required<Pick<T, K>>; /** * Make specific properties optional while keeping others required */ export type OptionalFields<T, K extends keyof T> = Omit<T, K> & Partial<Pick<T, K>>; /** * Make specific properties nullable */ export type NullableFields<T, K extends keyof T> = Omit<T, K> & { [P in K]: T[P] | null; }; // ============================================ // Deep Utilities // ============================================ /** * Deep readonly - makes all nested properties readonly */ export type DeepReadonly<T> = T extends (infer U)[] ? ReadonlyArray<DeepReadonly<U>> : T extends object ? { readonly [P in keyof T]: DeepReadonly<T[P]> } : T; /** * Deep required - makes all nested properties required */ export type DeepRequired<T> = T extends object ? { [P in keyof T]-?: DeepRequired<T[P]> } : T; /** * Deep mutable - removes readonly from all nested properties */ export type DeepMutable<T> = T extends (infer U)[] ? DeepMutable<U>[] : T extends object ? { -readonly [P in keyof T]: DeepMutable<T[P]> } : T; // ============================================ // Object Utilities // ============================================ /** * Get the keys of an object as a union type */ export type KeyOf<T> = keyof T; /** * Get the values of an object as a union type */ export type ValueOf<T> = T[keyof T]; /** * Create a type with only properties that extend a value type */ export type PickByValue<T, V> = Pick< T, { [K in keyof T]: T[K] extends V ? K : never }[keyof T] >; /** * Create a type without properties that extend a value type */ export type OmitByValue<T, V> = Pick< T, { [K in keyof T]: T[K] extends V ? never : K }[keyof T] >; /** * Make all properties mutable (remove readonly) */ export type Mutable<T> = { -readonly [P in keyof T]: T[P]; }; /** * Make all properties in a union type a single object type */ export type UnionToIntersection<U> = ( U extends unknown ? (k: U) => void : never ) extends (k: infer I) => void ? I : never; /** * Get only the string keys of an object */ export type StringKeyOf<T> = Extract<keyof T, string>; /** * Get only the numeric keys of an object */ export type NumericKeyOf<T> = Extract<keyof T, number>; // ============================================ // Function Utilities // ============================================ /** * Extract the return type of an async function */ export type AsyncReturnType<T extends (...args: unknown[]) => Promise<unknown>> = T extends (...args: unknown[]) => Promise<infer R> ? R : never; /** * A function that can be called with no arguments */ export type VoidFunction = () => void; /** * A function that returns a promise */ export type AsyncVoidFunction = () => Promise<void>; /** * Generic callback function type */ export type Callback<T = void> = () => T; /** * Generic async callback function type */ export type AsyncCallback<T = void> = () => Promise<T>; /** * Handler function for events */ export type Handler<T, R = void> = (value: T) => R; /** * Async handler function for events */ export type AsyncHandler<T, R = void> = (value: T) => Promise<R>; // ============================================ // Array Utilities // ============================================ /** * Get the element type of an array */ export type ArrayElement<T extends readonly unknown[]> = T extends readonly (infer E)[] ? E : never; /** * Ensure a type is an array */ export type EnsureArray<T> = T extends unknown[] ? T : T[]; /** * Non-empty array type - guarantees at least one element */ export type NonEmptyArray<T> = [T, ...T[]]; /** * Array with exactly N elements */ export type FixedLengthArray<T, N extends number, R extends T[] = []> = R['length'] extends N ? R : FixedLengthArray<T, N, [...R, T]>; /** * Tuple from array */ export type Tuple<T, N extends number> = N extends N ? number extends N ? T[] : _TupleOf<T, N, []> : never; type _TupleOf<T, N extends number, R extends unknown[]> = R['length'] extends N ? R : _TupleOf<T, N, [T, ...R]>; // ============================================ // String Utilities // ============================================ /** * Create a branded type for type-safe IDs * Prevents accidentally mixing up different ID types */ export type Brand<T, B extends string> = T & { __brand: B }; /** * Branded ID types for common entities */ export type UserId = Brand<number, 'UserId'>; export type ProductId = Brand<number, 'ProductId'>; export type OrderId = Brand<number, 'OrderId'>; export type CategoryId = Brand<number, 'CategoryId'>; export type AddressId = Brand<number, 'AddressId'>; /** * String literal to type */ export type Stringify<T> = T extends string ? T : never; /** * Template literal type for paths */ export type PathString = `/${string}`; /** * Email string type (branded) */ export type Email = Brand<string, 'Email'>; /** * URL string type (branded) */ export type URLString = Brand<string, 'URL'>; // ============================================ // Promise Utilities // ============================================ /** * Make a type promisable (can be T or Promise<T>) */ export type MaybePromise<T> = T | Promise<T>; /** * Unwrap nested promises */ export type DeepAwaited<T> = T extends Promise<infer U> ? DeepAwaited<U> : T; // ============================================ // React Utilities // ============================================ import type { ReactNode, ComponentType } from 'react'; /** * Props with children */ export type PropsWithChildren<P = object> = P & { children?: ReactNode; }; /** * Props with className */ export type PropsWithClassName<P = object> = P & { className?: string; }; /** * Props with both children and className */ export type PropsWithStyle<P = object> = P & { children?: ReactNode; className?: string; style?: React.CSSProperties; }; /** * Common component props */ export interface CommonProps { className?: string; id?: string; 'data-testid'?: string; } /** * Extract props type from a component */ export type ComponentProps<T> = T extends ComponentType<infer P> ? P : never; /** * Extract ref type from a component */ export type ComponentRef<T> = T extends ComponentType<{ ref?: infer R }> ? R : never; /** * Polymorphic component props helper */ export type PolymorphicProps<E extends React.ElementType, P = object> = P & Omit<React.ComponentPropsWithoutRef<E>, keyof P> & { as?: E; }; /** * Polymorphic component ref helper */ export type PolymorphicRef<E extends React.ElementType> = React.ComponentPropsWithRef<E>['ref']; // ============================================ // Form Utilities (extending common.ts) // ============================================ /** * Form field state */ export interface FieldState<T = string> { value: T; error: string | null; touched: boolean; dirty: boolean; } /** * Form state for multiple fields */ export type FormState<T extends Record<string, unknown>> = { [K in keyof T]: FieldState<T[K]>; }; /** * Form values from field state */ export type FormValuesFromState<T extends Record<string, FieldState<unknown>>> = { [K in keyof T]: T[K]['value']; }; // ============================================ // Conditional Types // ============================================ /** * If-then-else type */ export type If<C extends boolean, T, F> = C extends true ? T : F; /** * Check if types are equal */ export type Equals<X, Y> = (<T>() => T extends X ? 1 : 2) extends <T>() => T extends Y ? 1 : 2 ? true : false; /** * Check if a type is never */ export type IsNever<T> = [T] extends [never] ? true : false; /** * Check if a type is any */ export type IsAny<T> = 0 extends 1 & T ? true : false; // ============================================ // Utility Functions // ============================================ /** * Assert that a value is of a certain type (compile-time only) */ // eslint-disable-next-line @typescript-eslint/no-unused-vars export function assertType<T>(value: T): void { // No-op, just for type checking } /** * Create a branded value */ export function brand<T, B extends string>(value: T): Brand<T, B> { return value as Brand<T, B>; } /** * Check if array is non-empty */ export function isNonEmptyArray<T>(arr: T[]): arr is NonEmptyArray<T> { return arr.length > 0; } /** * Type guard for checking if a value is defined (not null or undefined) */ export function isDefined<T>(value: T | null | undefined): value is T { return value !== null && value !== undefined; } /** * Type guard for checking if a value is a non-null object */ export function isObject(value: unknown): value is Record<string, unknown> { return typeof value === 'object' && value !== null; } /** * Type guard for checking if a value is a string */ export function isString(value: unknown): value is string { return typeof value === 'string'; } /** * Type guard for checking if a value is a number */ export function isNumber(value: unknown): value is number { return typeof value === 'number' && !Number.isNaN(value); } |