'use strict'; const doctrine = require('doctrine'); const pragmaUtil = require('./pragma'); // eslint-disable-next-line valid-jsdoc /** * @template {(_: object) => any} T * @param {T} fn * @returns {T} */ function memoize(fn) { const cache = new WeakMap(); // @ts-ignore return function memoizedFn(arg) { const cachedValue = cache.get(arg); if (cachedValue !== undefined) { return cachedValue; } const v = fn(arg); cache.set(arg, v); return v; }; } const getPragma = memoize(pragmaUtil.getFromContext); const getCreateClass = memoize(pragmaUtil.getCreateClassFromContext); /** * @param {ASTNode} node * @param {Context} context * @returns {boolean} */ function isES5Component(node, context) { const pragma = getPragma(context); const createClass = getCreateClass(context); if (!node.parent || !node.parent.callee) { return false; } const callee = node.parent.callee; // React.createClass({}) if (callee.type === 'MemberExpression') { return callee.object.name === pragma && callee.property.name === createClass; } // createClass({}) if (callee.type === 'Identifier') { return callee.name === createClass; } return false; } /** * Check if the node is explicitly declared as a descendant of a React Component * @param {any} node * @param {Context} context * @returns {boolean} */ function isExplicitComponent(node, context) { const sourceCode = context.getSourceCode(); let comment; // Sometimes the passed node may not have been parsed yet by eslint, and this function call crashes. // Can be removed when eslint sets "parent" property for all nodes on initial AST traversal: https://github.com/eslint/eslint-scope/issues/27 // eslint-disable-next-line no-warning-comments // FIXME: Remove try/catch when https://github.com/eslint/eslint-scope/issues/27 is implemented. try { comment = sourceCode.getJSDocComment(node); } catch (e) { comment = null; } if (comment === null) { return false; } let commentAst; try { commentAst = doctrine.parse(comment.value, { unwrap: true, tags: ['extends', 'augments'], }); } catch (e) { // handle a bug in the archived `doctrine`, see #2596 return false; } const relevantTags = commentAst.tags.filter((tag) => tag.name === 'React.Component' || tag.name === 'React.PureComponent'); return relevantTags.length > 0; } /** * @param {ASTNode} node * @param {Context} context * @returns {boolean} */ function isES6Component(node, context) { const pragma = getPragma(context); if (isExplicitComponent(node, context)) { return true; } if (!node.superClass) { return false; } if (node.superClass.type === 'MemberExpression') { return node.superClass.object.name === pragma && /^(Pure)?Component$/.test(node.superClass.property.name); } if (node.superClass.type === 'Identifier') { return /^(Pure)?Component$/.test(node.superClass.name); } return false; } /** * Get the parent ES5 component node from the current scope * @param {Context} context * @returns {ASTNode|null} */ function getParentES5Component(context) { let scope = context.getScope(); while (scope) { // @ts-ignore const node = scope.block && scope.block.parent && scope.block.parent.parent; if (node && isES5Component(node, context)) { return node; } scope = scope.upper; } return null; } /** * Get the parent ES6 component node from the current scope * @param {Context} context * @returns {ASTNode | null} */ function getParentES6Component(context) { let scope = context.getScope(); while (scope && scope.type !== 'class') { scope = scope.upper; } const node = scope && scope.block; if (!node || !isES6Component(node, context)) { return null; } return node; } /** * Checks if a component extends React.PureComponent * @param {ASTNode} node * @param {Context} context * @returns {boolean} */ function isPureComponent(node, context) { const pragma = getPragma(context); const sourceCode = context.getSourceCode(); if (node.superClass) { return new RegExp(`^(${pragma}\\.)?PureComponent$`).test(sourceCode.getText(node.superClass)); } return false; } /** * @param {ASTNode} node * @returns {boolean} */ function isStateMemberExpression(node) { return node.type === 'MemberExpression' && node.object.type === 'ThisExpression' && node.property.name === 'state'; } module.exports = { isES5Component, isES6Component, getParentES5Component, getParentES6Component, isExplicitComponent, isPureComponent, isStateMemberExpression, };