02-nested-boolean-logic.mts

/*
 * This example demonstates nested boolean logic - e.g. (x OR y) AND (a OR b).
 *
 * Usage:
 *   node ./examples/02-nested-boolean-logic.js
 *
 * For detailed output:
 *   DEBUG=json-rules-engine node ./examples/02-nested-boolean-logic.js
 */

import "colors";
import { Engine } from "json-rules-engine";

async function start() {
  /**
   * Setup a new engine
   */
  const engine = new Engine();

  // define a rule for detecting the player has exceeded foul limits.  Foul out any player who:
  // (has committed 5 fouls AND game is 40 minutes) OR (has committed 6 fouls AND game is 48 minutes)
  engine.addRule({
    conditions: {
      any: [
        {
          all: [
            {
              fact: "gameDuration",
              operator: "equal",
              value: 40,
            },
            {
              fact: "personalFoulCount",
              operator: "greaterThanInclusive",
              value: 5,
            },
          ],
          name: "short foul limit",
        },
        {
          all: [
            {
              fact: "gameDuration",
              operator: "equal",
              value: 48,
            },
            {
              not: {
                fact: "personalFoulCount",
                operator: "lessThan",
                value: 6,
              },
            },
          ],
          name: "long foul limit",
        },
      ],
    },
    event: {
      // define the event to fire when the conditions evaluate truthy
      type: "fouledOut",
      params: {
        message: "Player has fouled out!",
      },
    },
  });

  /**
   * define the facts
   * note: facts may be loaded asynchronously at runtime; see the advanced example below
   */
  const facts = {
    personalFoulCount: 6,
    gameDuration: 40,
  };

  const { events } = await engine.run(facts);

  events.map((event) => console.log(event.params!.message.red));
}
export default start();
/*
 * OUTPUT:
 *
 * Player has fouled out!
 */