The idea

Given a specific scope what is the easiest way to write various rules that be tested against the scope for various reasons

Useful for testing & validation Business Logic stored as json.

Getting started

npm install rule-filter-validator

validatePayload(filter, payload, [strict = false])

View all methods and functions

Examples

const SCOPE = {
    person: {
        id: 1,
        dob: "1998-02-18",
        age: 23,
        active: true,
        gender: 'F'
    }
}

const rule: Filter = {
    "person": {
        "age": {
            "_gt": 18,
            "_lt": 25
        }
    }
}

let errors = validatePayload(rule, SCOPE);
return ! errors.length // true

Strictness

By default tests are case and type insensitive, meaning:

Calling validatePayload(filter, payload, [strict = false]) with strict = true will make the validator to be case and type sensitive.

_contains always compares as strings and is therefore not type sensitive

Advance Usage

Find a matching price rule

const prices = [
    {
        label: 'Child price'
        price: 100,
        logic: {
            "person": {
                "age": {
                    "_lt": 18
                }
            }
        }
    },
    {
        label: 'Adult price'
        price: 200,
        logic: {
            "person": {
                "age": {
                    "_gte": 18
                }
            }
        }
    }
]

const scope = getUserScope(); // You implement this.

const priceToPay = prices.find(({ price, logic }) => {
    let e = validatePayload(logic, scope)
    return ! e.length
})

Methods

• validatePayload(Filter, Payload, strict?)

  This is the main function that validates the payload against the filter. It returns an array of errors, if any.

• invertFilter(Filter)

  Inverts the filter, so that the filter will return the opposite of what it would have returned before.

• extractFieldFromFilter(Filter, Field, Path?)

  This extracts the given field from the passed Filter and returns a new Filter object that only contains only the given field and its children, if any.

All Operands (Functions)