README.md

JSON Schema Event

DRY Castore EventType definition using JSON Schemas and json-schema-to-ts

📥 Installation

# npm
npm install @castore/json-schema-event

# yarn
yarn add @castore/json-schema-event

This package has @castore/core and json-schema-to-ts (above v2) as peer dependencies, so you will have to install them as well:

# npm
npm install @castore/core json-schema-to-ts

# yarn
yarn add @castore/core json-schema-to-ts

👩‍💻 Usage

import { JSONSchemaEventType } from '@castore/json-schema-event';

const userCreatedPayloadSchema = {
  type: 'object',
  properties: {
    name: { type: 'string' },
    age: { type: 'string' },
  },
  required: ['name', 'age'],
  additionalProperties: false,
} as const; // 👈 Don't forget the "as const" statement
// (Cf json-schema-to-ts documentation)

const userCreatedMetadataSchema = {
  type: 'object',
  properties: {
    invitedBy: { type: 'string' },
  },
  additionalProperties: false,
} as const;

// 👇 generics are correctly inferred
const userCreatedEventType = new JSONSchemaEventType({
  type: 'USER_CREATED',
  payloadSchema: userCreatedPayloadSchema,
  metadataSchema: userCreatedMetadataSchema,
});

👇 Equivalent to:

import { EventType } from '@castore/core';

const userCreatedEventType = new EventType<
  'USER_CREATED',
  { name: string; age: number },
  { invitedBy?: string }
>({ type: 'USER_CREATED' });

⚙️ Properties & Methods

JSONSchemaEventType implements the EventType class and adds the following properties to it:

• payloadSchema (?object): The event type payload JSON schema

const payloadSchema = userCreatedEventType.payloadSchema;
// => userCreatedPayloadSchema

• metadataSchema (?object): The event type metadata JSON schema

const metadataSchema = userCreatedEventType.metadataSchema;
// => userCreatedMetadataSchema