Types

The public types prefID exports, so you can annotate your own functions and stores.

PrefixedId

The core type. PrefixedId<P> is a template literal type describing any string that starts with ${P}_.

type PrefixedId<P extends string = string> = `${P}_${string}`;

import type { PrefixedId } from "prefid";

type UserId = PrefixedId<"user">;
//   = `user_${string}`

function getUser(id: UserId) { /* ... */ }

getUser("user_abc"); // ✅
getUser("order_abc"); // ❌ not assignable to `user_${string}`

IdOptions & IdGenerator

IdOptions is the options object accepted by createId, and IdGenerator is the type of the generator function it returns.

import type { IdOptions, IdGenerator } from "prefid";

const options: IdOptions = { size: 16, separator: "_" };

const gen: IdGenerator = createId(options);

EnsureUniqueOptions

The options object accepted by ensureUnique — currently just maxAttempts.