163 lines
6.0 KiB
JavaScript
163 lines
6.0 KiB
JavaScript
|
/**
|
||
|
* @fileoverview Rule to flag use of implied eval via setTimeout and setInterval
|
||
|
* @author James Allardice
|
||
|
*/
|
||
|
|
||
|
"use strict";
|
||
|
|
||
|
//------------------------------------------------------------------------------
|
||
|
// Rule Definition
|
||
|
//------------------------------------------------------------------------------
|
||
|
|
||
|
module.exports = {
|
||
|
meta: {
|
||
|
docs: {
|
||
|
description: "disallow the use of `eval()`-like methods",
|
||
|
category: "Best Practices",
|
||
|
recommended: false,
|
||
|
url: "https://eslint.org/docs/rules/no-implied-eval"
|
||
|
},
|
||
|
|
||
|
schema: []
|
||
|
},
|
||
|
|
||
|
create(context) {
|
||
|
const CALLEE_RE = /^(setTimeout|setInterval|execScript)$/;
|
||
|
|
||
|
/*
|
||
|
* Figures out if we should inspect a given binary expression. Is a stack
|
||
|
* of stacks, where the first element in each substack is a CallExpression.
|
||
|
*/
|
||
|
const impliedEvalAncestorsStack = [];
|
||
|
|
||
|
//--------------------------------------------------------------------------
|
||
|
// Helpers
|
||
|
//--------------------------------------------------------------------------
|
||
|
|
||
|
/**
|
||
|
* Get the last element of an array, without modifying arr, like pop(), but non-destructive.
|
||
|
* @param {array} arr What to inspect
|
||
|
* @returns {*} The last element of arr
|
||
|
* @private
|
||
|
*/
|
||
|
function last(arr) {
|
||
|
return arr ? arr[arr.length - 1] : null;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Checks if the given MemberExpression node is a potentially implied eval identifier on window.
|
||
|
* @param {ASTNode} node The MemberExpression node to check.
|
||
|
* @returns {boolean} Whether or not the given node is potentially an implied eval.
|
||
|
* @private
|
||
|
*/
|
||
|
function isImpliedEvalMemberExpression(node) {
|
||
|
const object = node.object,
|
||
|
property = node.property,
|
||
|
hasImpliedEvalName = CALLEE_RE.test(property.name) || CALLEE_RE.test(property.value);
|
||
|
|
||
|
return object.name === "window" && hasImpliedEvalName;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Determines if a node represents a call to a potentially implied eval.
|
||
|
*
|
||
|
* This checks the callee name and that there's an argument, but not the type of the argument.
|
||
|
*
|
||
|
* @param {ASTNode} node The CallExpression to check.
|
||
|
* @returns {boolean} True if the node matches, false if not.
|
||
|
* @private
|
||
|
*/
|
||
|
function isImpliedEvalCallExpression(node) {
|
||
|
const isMemberExpression = (node.callee.type === "MemberExpression"),
|
||
|
isIdentifier = (node.callee.type === "Identifier"),
|
||
|
isImpliedEvalCallee =
|
||
|
(isIdentifier && CALLEE_RE.test(node.callee.name)) ||
|
||
|
(isMemberExpression && isImpliedEvalMemberExpression(node.callee));
|
||
|
|
||
|
return isImpliedEvalCallee && node.arguments.length;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Checks that the parent is a direct descendent of an potential implied eval CallExpression, and if the parent is a CallExpression, that we're the first argument.
|
||
|
* @param {ASTNode} node The node to inspect the parent of.
|
||
|
* @returns {boolean} Was the parent a direct descendent, and is the child therefore potentially part of a dangerous argument?
|
||
|
* @private
|
||
|
*/
|
||
|
function hasImpliedEvalParent(node) {
|
||
|
|
||
|
// make sure our parent is marked
|
||
|
return node.parent === last(last(impliedEvalAncestorsStack)) &&
|
||
|
|
||
|
// if our parent is a CallExpression, make sure we're the first argument
|
||
|
(node.parent.type !== "CallExpression" || node === node.parent.arguments[0]);
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Checks if our parent is marked as part of an implied eval argument. If
|
||
|
* so, collapses the top of impliedEvalAncestorsStack and reports on the
|
||
|
* original CallExpression.
|
||
|
* @param {ASTNode} node The CallExpression to check.
|
||
|
* @returns {boolean} True if the node matches, false if not.
|
||
|
* @private
|
||
|
*/
|
||
|
function checkString(node) {
|
||
|
if (hasImpliedEvalParent(node)) {
|
||
|
|
||
|
// remove the entire substack, to avoid duplicate reports
|
||
|
const substack = impliedEvalAncestorsStack.pop();
|
||
|
|
||
|
context.report({ node: substack[0], message: "Implied eval. Consider passing a function instead of a string." });
|
||
|
}
|
||
|
}
|
||
|
|
||
|
//--------------------------------------------------------------------------
|
||
|
// Public
|
||
|
//--------------------------------------------------------------------------
|
||
|
|
||
|
return {
|
||
|
CallExpression(node) {
|
||
|
if (isImpliedEvalCallExpression(node)) {
|
||
|
|
||
|
// call expressions create a new substack
|
||
|
impliedEvalAncestorsStack.push([node]);
|
||
|
}
|
||
|
},
|
||
|
|
||
|
"CallExpression:exit"(node) {
|
||
|
if (node === last(last(impliedEvalAncestorsStack))) {
|
||
|
|
||
|
/*
|
||
|
* Destroys the entire sub-stack, rather than just using
|
||
|
* last(impliedEvalAncestorsStack).pop(), as a CallExpression is
|
||
|
* always the bottom of a impliedEvalAncestorsStack substack.
|
||
|
*/
|
||
|
impliedEvalAncestorsStack.pop();
|
||
|
}
|
||
|
},
|
||
|
|
||
|
BinaryExpression(node) {
|
||
|
if (node.operator === "+" && hasImpliedEvalParent(node)) {
|
||
|
last(impliedEvalAncestorsStack).push(node);
|
||
|
}
|
||
|
},
|
||
|
|
||
|
"BinaryExpression:exit"(node) {
|
||
|
if (node === last(last(impliedEvalAncestorsStack))) {
|
||
|
last(impliedEvalAncestorsStack).pop();
|
||
|
}
|
||
|
},
|
||
|
|
||
|
Literal(node) {
|
||
|
if (typeof node.value === "string") {
|
||
|
checkString(node);
|
||
|
}
|
||
|
},
|
||
|
|
||
|
TemplateLiteral(node) {
|
||
|
checkString(node);
|
||
|
}
|
||
|
};
|
||
|
|
||
|
}
|
||
|
};
|