eslint-plugin-unicorn-x/rules/utils/boolean.js

More than 100 powerful ESLint rules

import isLogicalExpression from './is-logical-expression.js';

const isLogicNot = (node) =>
	node?.type === 'UnaryExpression' && node.operator === '!';
const isLogicNotArgument = (node) =>
	isLogicNot(node.parent) && node.parent.argument === node;
const isBooleanCallArgument = (node) =>
	isBooleanCall(node.parent) && node.parent.arguments[0] === node;
const isBooleanCall = (node) =>
	node?.type === 'CallExpression' &&
	node.callee.type === 'Identifier' &&
	node.callee.name === 'Boolean' &&
	node.arguments.length === 1;
const isVueBooleanAttributeValue = (node) =>
	node?.type === 'VExpressionContainer' &&
	node.parent.type === 'VAttribute' &&
	node.parent.directive &&
	node.parent.value === node &&
	node.parent.key.type === 'VDirectiveKey' &&
	node.parent.key.name.type === 'VIdentifier' &&
	(node.parent.key.name.rawName === 'if' ||
		node.parent.key.name.rawName === 'else-if' ||
		node.parent.key.name.rawName === 'show');

/**
Check if the value of node is a `boolean`.

@param {Node} node
@returns {boolean}
*/
export function isBooleanNode(node) {
	if (
		isLogicNot(node) ||
		isLogicNotArgument(node) ||
		isBooleanCall(node) ||
		isBooleanCallArgument(node)
	) {
		return true;
	}

	const {parent} = node;
	if (isVueBooleanAttributeValue(parent)) {
		return true;
	}

	if (
		(parent.type === 'IfStatement' ||
			parent.type === 'ConditionalExpression' ||
			parent.type === 'WhileStatement' ||
			parent.type === 'DoWhileStatement' ||
			parent.type === 'ForStatement') &&
		parent.test === node
	) {
		return true;
	}

	if (isLogicalExpression(parent)) {
		return isBooleanNode(parent);
	}

	return false;
}

/**
Get the boolean type-casting ancestor.

@typedef {{ node: Node, isNegative: boolean }} Result

@param {Node} node
@returns {Result}
*/
export function getBooleanAncestor(node) {
	let isNegative = false;

	while (true) {
		if (isLogicNotArgument(node)) {
			isNegative = !isNegative;
			node = node.parent;
		} else if (isBooleanCallArgument(node)) {
			node = node.parent;
		} else {
			break;
		}
	}

	return {node, isNegative};
}