Installation and Setup

First, add the module to your application through your preferred package manager,

npm install json-logic-engine 
# or
yarn add json-logic-engine
# or 
bun add json-logic-engine

Then import the module, and try to set up a "Hello, World!"

import { LogicEngine } from 'json-logic-engine'

const engine = new LogicEngine()

// we can make use of the modules function compilation
const f = engine.build({
  cat: ["Hello, ", { var: '' }, "!"]
})

console.log(f("World")) // prints "Hello, World!"

Or alternatively, make use of the interpreter using:

import { LogicEngine } from 'json-logic-engine'

const engine = new LogicEngine()

// we can make use of the modules function compilation
console.log(engine.run({ cat: ["Hello, ", { var: '' }, "!"] }, "World"))

Please note that at the time of writing that while the interpreter is still available in this module, the compilation mechanism yields far better performance in all use-cases & supports all of the same features. The only time you may wish to use .run is when you are switching over from json-logic-js and migrating from it's .apply method.