ZEN Module Documentation

A module for evaluating ZEN expressions and making decisions based on provided context.

Basic Usage

import zen from 'zen';

// Evaluate a ZEN expression
const result = zen.evaluateExpression('value > 10', {{ value: 15 });

// Evaluate using a decision file (from same project)
const decision = await zen.evaluate('pricing-rules', {
  orderId: '123',
  total: 99.99
});

API Reference

evaluateExpression(expression, context)

Evaluates a ZEN expression with the given context.

const context = { age: 25 };
const result = zen.evaluateExpression('age >= 18', context);
// result: true

evaluateUnaryExpression(expression, context)

Evaluates a ZEN unary expression that returns a boolean.

const context = { $: 'active'};
const result = zen.evaluateUnaryExpression('"active"', context);
// result: true

evaluate(key, context, options?)

Evaluates a decision file from the same project identified by the key using provided context.

const result = await zen.evaluate('discount-rules', {
  customer: { type: 'premium' },
  orderTotal: 150
}, {
  trace: true  // Enable tracing for debugging
});

Response format:

{
  result: any,           // Evaluation result
  performance: string,   // Performance metrics
  trace?: any           // Trace data if enabled
}

Context Requirements (Unary)

All context objects must contain a $ key with the values to be evaluated
The $ object holds the variables referenced in expressions

Options

EvaluateOptions for the evaluate method:

{
  trace?: boolean  // Enable/disable evaluation tracing
}