json-rules-engine/src/operator.js at master · CacheControl/json-rules-engine · GitHub

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'use strict'

export default class Operator {

/**

* Constructor

* @param {string} name - operator identifier

* @param {function(factValue, jsonValue)} callback - operator evaluation method

* @param {function} [factValueValidator] - optional validator for asserting the data type of the fact

* @returns {Operator} - instance

constructor (name, cb, factValueValidator) {

this.name = String(name)

if (!name) throw new Error('Missing operator name')

if (typeof cb !== 'function') throw new Error('Missing operator callback')

this.cb = cb

this.factValueValidator = factValueValidator

if (!this.factValueValidator) this.factValueValidator = () => true

}

/**

* Takes the fact result and compares it to the condition 'value', using the callback

* @param {mixed} factValue - fact result

* @param {mixed} jsonValue - "value" property of the condition

* @returns {Boolean} - whether the values pass the operator test

evaluate (factValue, jsonValue) {

return this.factValueValidator(factValue) && this.cb(factValue, jsonValue)

}

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