# Flatten Object With Periods • Obsidian Garden

# Flatten Object With Periods

This helper generates Typescript types for i18n dictionary json files by flattening it with period delimiter. Supports plural forms.

Used for typing i18n.js dictionaries;

    import en from './en.json';type TranslationPath = Flatten<typeof en>;const t = (key: TranslationPath, options?: TranslateOptions) =>    I18nLib.t(key, options);

Flatten type defined here:

    // This one based on answer from StackOverflow:// https://stackoverflow.com/questions/58434389/typescript-deep-keyof-of-a-nested-objectexport type Flatten<T, D extends number = 5> = [D] extends [never]  ? never  : T extends PluralForm // plural object  ? ''  : T extends object  ? { [K in keyof T]-?: Join<K, Flatten<T[K], Prev[D]>> }[keyof T]  : '';// Fix it for you plural formtype PluralForm = Record<'one' | 'few' | 'many', string>;type Join<K, P> = K extends string | number  ? P extends string | number    ? `${K}${'' extends P ? '' : '.'}${P}`    : never  : never;type Prev = [never, 0, 1, 2, 3, 4, 5, ...Array<0>];