@toreda/strong-types/src/rule.ts

Better TypeScript code in fewer lines.

/**
 *	MIT License
 *
 *	Copyright (c) 2019 - 2021 Toreda, Inc.
 *
 *	Permission is hereby granted, free of charge, to any person obtaining a copy
 *	of this software and associated documentation files (the "Software"), to deal
 *	in the Software without restriction, including without limitation the rights
 *	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *	copies of the Software, and to permit persons to whom the Software is
 *	furnished to do so, subject to the following conditions:

 * 	The above copyright notice and this permission notice shall be included in all
 * 	copies or substantial portions of the Software.
 *
 * 	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * 	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * 	SOFTWARE.
 *
 */

import {RuleNode} from './rule/node';
import {RuleNodeType} from './rule/node/type';

/**
 * Single rule applied to a node. Can be modified by other rules, matches,
 * specifiers, and flags such as invert.
 *
 * @category Rules
 */
export class Rule {
	public readonly nodes: RuleNode<unknown>[];

	constructor() {
		this.nodes = [];
	}

	public add<NodeT>(node: RuleNode<NodeT>): void {
		if (node.type !== RuleNodeType.CMP) {
			return;
		}

		this.nodes.push(node as RuleNode<unknown>);
	}

	public run(value: unknown | null): boolean {
		if (!this.nodes.length) {
			return false;
		}

		let trueCount = 0;
		for (const node of this.nodes) {
			const result = node.execute(value);
			if (result) {
				trueCount++;
			}
		}

		// Require at least comparison in set of
		// OR operators to be true.
		return trueCount > 0;
	}

	public reset(): void {
		this.nodes.length = 0;
	}
}