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Schema APIs

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@livon/schema exports schema builders and schema combinators.
This section documents each schema API with a focused usage example. Use it as the reference when implementing or reviewing schema definitions.

Foundations​

Primitive schemas​

Collection schemas​

Combinators​

API schemas​

Complete example (all schema APIs)​

import {
  after,
  and,
  api,
  array,
  before,
  binary,
  boolean,
  date,
  enumeration,
  literal,
  number,
  object,
  operation,
  or,
  string,
  subscription,
  tuple,
  union,
} from '@livon/schema';

const Author = string().min(2);
const MessageText = string().min(1);
const Priority = number().int().min(0);
const IsPinned = boolean();
const CreatedAt = date();
const Role = enumeration('Role').values('user', 'moderator', 'admin');

const Tags = array({name: 'Tags', item: string()});
const Position = tuple({name: 'Position', items: [number(), number()]});
const GlobalRoom = literal({name: 'GlobalRoom', value: 'global'});
const Attachment = binary({name: 'Attachment'});

const TextOrAttachment = union({
  name: 'TextOrAttachment',
  options: [MessageText, Attachment],
});

const RoomSelector = or({
  name: 'RoomSelector',
  options: [GlobalRoom, string()],
});

const NormalizedText = before({
  schema: MessageText,
  hook: (input) => (typeof input === 'string' ? input.trim() : input),
});

const LowerText = after({
  schema: NormalizedText,
  hook: (value) => value.toLowerCase(),
});

const MessageInput = object({
  name: 'MessageInput',
  shape: {
    author: Author,
    text: NormalizedText,
    payload: TextOrAttachment,
    room: RoomSelector,
    priority: Priority,
    isPinned: IsPinned,
    createdAt: CreatedAt,
    role: Role,
    tags: Tags,
    position: Position,
  },
});

const WithId = object({
  name: 'WithId',
  shape: {
    id: string(),
  },
});

const MessageWithId = and({
  left: MessageInput,
  right: WithId,
  name: 'MessageWithId',
});

const sendMessage = operation({
  input: MessageInput,
  output: MessageWithId,
  exec: async (input) => ({
    ...input,
    text: LowerText.parse(input.text),
    payload: input.text,
    id: 'msg-1',
  }),
  publish: {
    onMessage: (output) => output,
  },
});

const OnMessage = subscription({
  payload: MessageWithId,
});

const ApiSchema = api({
  operations: {sendMessage},
  subscriptions: {onMessage: OnMessage},
});

export const serverSchema = ApiSchema;

Parameters​

The complete example intentionally stays compact. Each function parameter used above is documented on its dedicated schema page:

Advanced APIs​