@bernierllc/nevar-mixin-bridge

Mixin definition utilities for the Nevar rules engine. Allows domain-specific extensions to register triggers, operators, actions, and context providers onto a Nevar instance under a namespace.

Installation

npm install @bernierllc/nevar-mixin-bridge

Usage

import { defineMixin } from '@bernierllc/nevar-mixin-bridge';
import type { MixinDefinition } from '@bernierllc/nevar-mixin-bridge';
import { z } from 'zod';

const ecommerceMixin = defineMixin('ecommerce', {
  triggers: [
    {
      key: 'order.placed',
      payloadSchema: z.object({ orderId: z.string(), total: z.number() }),
      description: 'Fires when an order is placed',
      category: 'commerce',
    },
  ],
  operators: [
    {
      name: 'currency_gt',
      definition: {
        label: 'Currency Greater Than',
        category: 'commerce',
        evaluate: (field, target) => Number(field) > Number(target),
        schema: z.number(),
        fieldTypes: ['number'],
      },
    },
  ],
  actions: [
    {
      actionType: 'send-receipt',
      definition: {
        execute: async (config, context) => {
          // Send receipt logic
          return { sent: true };
        },
      },
    },
  ],
  contextProviders: [
    {
      prefix: 'order',
      provider: async (payload) => ({
        total: 99.99,
        currency: 'USD',
      }),
    },
  ],
  methods: {
    getOrderStatus: (orderId: string) => 'shipped',
  },
});

// Apply to a Nevar instance
ecommerceMixin(nevar);

// Methods are accessible under the namespace
// nevar.ecommerce.getOrderStatus('order-1')

API

defineMixin(namespace, definition)

Creates a mixin function that can be applied to a Nevar instance. The returned function registers all triggers, operators, actions, and context providers defined in the mixin, and mounts any methods at nevar[namespace].

Parameters:

• namespace: string - The namespace to mount methods under
• definition: MixinDefinition - The mixin definition containing triggers, operators, actions, context providers, and methods

Returns: (nevar: NevarLike) => void - A function that applies the mixin to a Nevar instance

Throws: NevarValidationError if the namespace is already registered on the instance.

Types

• MixinDefinition - Complete mixin definition with optional triggers, operators, actions, contextProviders, and methods
• MixinTrigger - Trigger definition with key, payloadSchema, optional description and category
• MixinOperator - Operator definition with name and definition: OperatorDefinition
• MixinAction - Action definition with actionType and definition: ActionHandlerDefinition
• MixinContextProvider - Context provider with prefix and provider function
• ActionHandlerDefinition - Action handler with execute function and optional description
• NevarLike - Minimal interface for a Nevar instance that supports registration methods

Integration Documentation

Logger Integration

This package does not integrate with @bernierllc/logger. As a core package, logger integration is optional and not included by default. Consumers should handle logging at the service layer.

NeverHub Integration

This package does not integrate with @bernierllc/neverhub-adapter. As a core package, NeverHub integration is not applicable. NeverHub registration should be handled by service-layer packages that compose this package.

License

Copyright (c) 2025 Bernier LLC. All rights reserved.