/** * @fileoverview Rule to flag when IIFE is not wrapped in parens * @author Ilya Volodin */ "use strict"; //------------------------------------------------------------------------------ // Requirements //------------------------------------------------------------------------------ const astUtils = require("../ast-utils"); //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { docs: { description: "require parentheses around immediate `function` invocations", category: "Best Practices", recommended: false, url: "https://eslint.org/docs/rules/wrap-iife" }, schema: [ { enum: ["outside", "inside", "any"] }, { type: "object", properties: { functionPrototypeMethods: { type: "boolean" } }, additionalProperties: false } ], fixable: "code" }, create(context) { const style = context.options[0] || "outside"; const includeFunctionPrototypeMethods = (context.options[1] && context.options[1].functionPrototypeMethods) || false; const sourceCode = context.getSourceCode(); /** * Check if the node is wrapped in () * @param {ASTNode} node node to evaluate * @returns {boolean} True if it is wrapped * @private */ function wrapped(node) { return astUtils.isParenthesised(sourceCode, node); } /** * Get the function node from an IIFE * @param {ASTNode} node node to evaluate * @returns {ASTNode} node that is the function expression of the given IIFE, or null if none exist */ function getFunctionNodeFromIIFE(node) { const callee = node.callee; if (callee.type === "FunctionExpression") { return callee; } if (includeFunctionPrototypeMethods && callee.type === "MemberExpression" && callee.object.type === "FunctionExpression" && (astUtils.getStaticPropertyName(callee) === "call" || astUtils.getStaticPropertyName(callee) === "apply") ) { return callee.object; } return null; } return { CallExpression(node) { const innerNode = getFunctionNodeFromIIFE(node); if (!innerNode) { return; } const callExpressionWrapped = wrapped(node), functionExpressionWrapped = wrapped(innerNode); if (!callExpressionWrapped && !functionExpressionWrapped) { context.report({ node, message: "Wrap an immediate function invocation in parentheses.", fix(fixer) { const nodeToSurround = style === "inside" ? innerNode : node; return fixer.replaceText(nodeToSurround, `(${sourceCode.getText(nodeToSurround)})`); } }); } else if (style === "inside" && !functionExpressionWrapped) { context.report({ node, message: "Wrap only the function expression in parens.", fix(fixer) { /* * The outer call expression will always be wrapped at this point. * Replace the range between the end of the function expression and the end of the call expression. * for example, in `(function(foo) {}(bar))`, the range `(bar))` should get replaced with `)(bar)`. * Replace the parens from the outer expression, and parenthesize the function expression. */ const parenAfter = sourceCode.getTokenAfter(node); return fixer.replaceTextRange( [innerNode.range[1], parenAfter.range[1]], `)${sourceCode.getText().slice(innerNode.range[1], parenAfter.range[0])}` ); } }); } else if (style === "outside" && !callExpressionWrapped) { context.report({ node, message: "Move the invocation into the parens that contain the function.", fix(fixer) { /* * The inner function expression will always be wrapped at this point. * It's only necessary to replace the range between the end of the function expression * and the call expression. For example, in `(function(foo) {})(bar)`, the range `)(bar)` * should get replaced with `(bar))`. */ const parenAfter = sourceCode.getTokenAfter(innerNode); return fixer.replaceTextRange( [parenAfter.range[0], node.range[1]], `${sourceCode.getText().slice(parenAfter.range[1], node.range[1])})` ); } }); } } }; } };