/** * @fileoverview Validate JSX maximum depth * @author Chris */ 'use strict'; const has = require('hasown'); const includes = require('array-includes'); const variableUtil = require('../util/variable'); const jsxUtil = require('../util/jsx'); const docsUrl = require('../util/docsUrl'); const reportC = require('../util/report'); // ------------------------------------------------------------------------------ // Rule Definition // ------------------------------------------------------------------------------ const messages = { wrongDepth: 'Expected the depth of nested jsx elements to be <= {{needed}}, but found {{found}}.', }; /** @type {import('eslint').Rule.RuleModule} */ module.exports = { meta: { docs: { description: 'Enforce JSX maximum depth', category: 'Stylistic Issues', recommended: false, url: docsUrl('jsx-max-depth'), }, messages, schema: [ { type: 'object', properties: { max: { type: 'integer', minimum: 0, }, }, additionalProperties: false, }, ], }, create(context) { const DEFAULT_DEPTH = 2; const option = context.options[0] || {}; const maxDepth = has(option, 'max') ? option.max : DEFAULT_DEPTH; function isExpression(node) { return node.type === 'JSXExpressionContainer'; } function hasJSX(node) { return jsxUtil.isJSX(node) || (isExpression(node) && jsxUtil.isJSX(node.expression)); } function isLeaf(node) { const children = node.children; return !children || children.length === 0 || !children.some(hasJSX); } function getDepth(node) { let count = 0; while (jsxUtil.isJSX(node.parent) || isExpression(node.parent)) { node = node.parent; if (jsxUtil.isJSX(node)) { count += 1; } } return count; } function report(node, depth) { reportC(context, messages.wrongDepth, 'wrongDepth', { node, data: { found: depth, needed: maxDepth, }, }); } function findJSXElementOrFragment(startNode, name, previousReferences) { function find(refs, prevRefs) { for (let i = refs.length - 1; i >= 0; i--) { if (has(refs[i], 'writeExpr')) { const writeExpr = refs[i].writeExpr; return (jsxUtil.isJSX(writeExpr) && writeExpr) || ((writeExpr && writeExpr.type === 'Identifier') && findJSXElementOrFragment(startNode, writeExpr.name, prevRefs)); } } return null; } const variable = variableUtil.getVariableFromContext(context, startNode, name); if (variable && variable.references) { const containDuplicates = previousReferences.some((ref) => includes(variable.references, ref)); // Prevent getting stuck in circular references if (containDuplicates) { return false; } return find(variable.references, previousReferences.concat(variable.references)); } return false; } function checkDescendant(baseDepth, children) { baseDepth += 1; (children || []).filter((node) => hasJSX(node)).forEach((node) => { if (baseDepth > maxDepth) { report(node, baseDepth); } else if (!isLeaf(node)) { checkDescendant(baseDepth, node.children); } }); } function handleJSX(node) { if (!isLeaf(node)) { return; } const depth = getDepth(node); if (depth > maxDepth) { report(node, depth); } } return { JSXElement: handleJSX, JSXFragment: handleJSX, JSXExpressionContainer(node) { if (node.expression.type !== 'Identifier') { return; } const element = findJSXElementOrFragment(node, node.expression.name, []); if (element) { const baseDepth = getDepth(node); checkDescendant(baseDepth, element.children); } }, }; }, };