@naturalcycles/js-lib/dist/types.js

Standard library for universal (browser + Node.js) javascript

/**
 * Symbol to indicate END of Sequence.
 */
export const END = Symbol('END');
/**
 * Symbol to indicate SKIP of item (e.g in AbortableMapper)
 */
export const SKIP = Symbol('SKIP');
/**
 * Symbol to indicate cache miss.
 * To distinguish from cache returning `undefined` or `null`.
 */
export const MISS = Symbol('MISS');
export const _passthroughMapper = item => item;
export const _passUndefinedMapper = () => undefined;
/**
 * Function that does nothings and returns `undefined`.
 */
export const _noop = (..._args) => undefined;
export const _passthroughPredicate = () => true;
export const _passNothingPredicate = () => false;
export const JWT_REGEX = /^[\w-]+\.[\w-]+\.[\w-]+$/;
/**
 * Needed due to https://github.com/microsoft/TypeScript/issues/13778
 * Only affects typings, no runtime effect.
 */
export const _stringMapValues = Object.values;
/**
 * Needed due to https://github.com/microsoft/TypeScript/issues/13778
 * Only affects typings, no runtime effect.
 */
export const _stringMapEntries = Object.entries;
/**
 * Alias of `Object.keys`, but returns keys typed as `keyof T`, not as just `string`.
 * This is how TypeScript should work, actually.
 */
export const _objectKeys = Object.keys;
/**
 * Alias of `Object.entries`, but returns better-typed output.
 *
 * So e.g you can use _objectEntries(obj).map([k, v] => {})
 * and `k` will be `keyof obj` instead of generic `string`.
 */
export const _objectEntries = Object.entries;
/**
 * Utility function that helps to cast *existing variable* to needed type T.
 *
 * @example
 * try {} catch (err) {
 *   // err is unknown here
 *   _typeCast<AppError>(err)
 *   // now err is of type AppError
 *   err.data = {} // can be done, because it was casted
 * }
 */
export function _typeCast(_v) { }
/**
 * Type-safe Object.assign that checks that part is indeed a Partial<T>
 */
export const _objectAssign = Object.assign;