@bernierllc/nevar-operator-registry

Operator registry with 12 built-in operators for the Nevar rules engine.

Installation

npm install @bernierllc/nevar-operator-registry

Usage

import { OperatorRegistry } from '@bernierllc/nevar-operator-registry';

const registry = new OperatorRegistry();

// All 12 built-in operators are pre-registered
registry.evaluate('eq', 'hello', 'hello'); // true
registry.evaluate('gt', 10, 5);            // true
registry.evaluate('in', 'a', ['a', 'b']);  // true
registry.evaluate('is_true', true, null);  // true

// List all operators
const operators = registry.list();

// Filter by category
const comparisons = registry.getByCategory('comparison');

// Register custom operators
registry.register('starts_with', {
  label: 'Starts With',
  category: 'string',
  evaluate: (field, target) => String(field).startsWith(String(target)),
  schema: z.string(),
  fieldTypes: ['string'],
});

Built-in Operators

| Operator | Category | Description | |----------|----------|-------------| | eq | comparison | Equal to | | neq | comparison | Not equal to | | gt | comparison | Greater than | | gte | comparison | Greater than or equal | | lt | comparison | Less than | | lte | comparison | Less than or equal | | in | membership | Value is in array | | not_in | membership | Value is not in array | | contains | membership | Array/string contains value | | not_contains | membership | Array/string does not contain value | | is_true | boolean | Value is truthy | | is_false | boolean | Value is falsy |

API

OperatorRegistry

Registry for managing built-in and custom operators. All 12 built-in operators are pre-registered on construction.

Constructor: new OperatorRegistry()

• register(name, definition) - Registers a custom operator. Throws NevarValidationError if the name is already registered
• get(name) - Returns the OperatorDefinition for the given name, or undefined
• has(name) - Returns true if the operator is registered
• list() - Returns all operators as serializable OperatorInfo[] (without evaluate functions)
• getByCategory(category) - Returns operators filtered by category
• evaluate(name, fieldValue, targetValue) - Evaluates a field value against a target using the named operator. Throws NevarEvaluationError for unknown operators

builtInOperators

Exported map of the 12 built-in operator definitions, useful for inspection or testing.

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.