shell bypass 403
/**
* @fileoverview Rule to enforce return statements in callbacks of array's methods
* @author Toru Nagashima
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require("./utils/ast-utils");
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
const TARGET_NODE_TYPE = /^(?:Arrow)?FunctionExpression$/u;
const TARGET_METHODS = /^(?:every|filter|find(?:Index)?|flatMap|forEach|map|reduce(?:Right)?|some|sort)$/u;
/**
* Checks a given code path segment is reachable.
* @param {CodePathSegment} segment A segment to check.
* @returns {boolean} `true` if the segment is reachable.
*/
function isReachable(segment) {
return segment.reachable;
}
/**
* Checks a given node is a member access which has the specified name's
* property.
* @param {ASTNode} node A node to check.
* @returns {boolean} `true` if the node is a member access which has
* the specified name's property. The node may be a `(Chain|Member)Expression` node.
*/
function isTargetMethod(node) {
return astUtils.isSpecificMemberAccess(node, null, TARGET_METHODS);
}
/**
* Returns a human-legible description of an array method
* @param {string} arrayMethodName A method name to fully qualify
* @returns {string} the method name prefixed with `Array.` if it is a class method,
* or else `Array.prototype.` if it is an instance method.
*/
function fullMethodName(arrayMethodName) {
if (["from", "of", "isArray"].includes(arrayMethodName)) {
return "Array.".concat(arrayMethodName);
}
return "Array.prototype.".concat(arrayMethodName);
}
/**
* Checks whether or not a given node is a function expression which is the
* callback of an array method, returning the method name.
* @param {ASTNode} node A node to check. This is one of
* FunctionExpression or ArrowFunctionExpression.
* @returns {string} The method name if the node is a callback method,
* null otherwise.
*/
function getArrayMethodName(node) {
let currentNode = node;
while (currentNode) {
const parent = currentNode.parent;
switch (parent.type) {
/*
* Looks up the destination. e.g.,
* foo.every(nativeFoo || function foo() { ... });
*/
case "LogicalExpression":
case "ConditionalExpression":
case "ChainExpression":
currentNode = parent;
break;
/*
* If the upper function is IIFE, checks the destination of the return value.
* e.g.
* foo.every((function() {
* // setup...
* return function callback() { ... };
* })());
*/
case "ReturnStatement": {
const func = astUtils.getUpperFunction(parent);
if (func === null || !astUtils.isCallee(func)) {
return null;
}
currentNode = func.parent;
break;
}
/*
* e.g.
* Array.from([], function() {});
* list.every(function() {});
*/
case "CallExpression":
if (astUtils.isArrayFromMethod(parent.callee)) {
if (
parent.arguments.length >= 2 &&
parent.arguments[1] === currentNode
) {
return "from";
}
}
if (isTargetMethod(parent.callee)) {
if (
parent.arguments.length >= 1 &&
parent.arguments[0] === currentNode
) {
return astUtils.getStaticPropertyName(parent.callee);
}
}
return null;
// Otherwise this node is not target.
default:
return null;
}
}
/* istanbul ignore next: unreachable */
return null;
}
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../shared/types').Rule} */
module.exports = {
meta: {
type: "problem",
docs: {
description: "enforce `return` statements in callbacks of array methods",
recommended: false,
url: "https://eslint.org/docs/rules/array-callback-return"
},
schema: [
{
type: "object",
properties: {
allowImplicit: {
type: "boolean",
default: false
},
checkForEach: {
type: "boolean",
default: false
}
},
additionalProperties: false
}
],
messages: {
expectedAtEnd: "{{arrayMethodName}}() expects a value to be returned at the end of {{name}}.",
expectedInside: "{{arrayMethodName}}() expects a return value from {{name}}.",
expectedReturnValue: "{{arrayMethodName}}() expects a return value from {{name}}.",
expectedNoReturnValue: "{{arrayMethodName}}() expects no useless return value from {{name}}."
}
},
create(context) {
const options = context.options[0] || { allowImplicit: false, checkForEach: false };
const sourceCode = context.getSourceCode();
let funcInfo = {
arrayMethodName: null,
upper: null,
codePath: null,
hasReturn: false,
shouldCheck: false,
node: null
};
/**
* Checks whether or not the last code path segment is reachable.
* Then reports this function if the segment is reachable.
*
* If the last code path segment is reachable, there are paths which are not
* returned or thrown.
* @param {ASTNode} node A node to check.
* @returns {void}
*/
function checkLastSegment(node) {
if (!funcInfo.shouldCheck) {
return;
}
let messageId = null;
if (funcInfo.arrayMethodName === "forEach") {
if (options.checkForEach && node.type === "ArrowFunctionExpression" && node.expression) {
messageId = "expectedNoReturnValue";
}
} else {
if (node.body.type === "BlockStatement" && funcInfo.codePath.currentSegments.some(isReachable)) {
messageId = funcInfo.hasReturn ? "expectedAtEnd" : "expectedInside";
}
}
if (messageId) {
const name = astUtils.getFunctionNameWithKind(node);
context.report({
node,
loc: astUtils.getFunctionHeadLoc(node, sourceCode),
messageId,
data: { name, arrayMethodName: fullMethodName(funcInfo.arrayMethodName) }
});
}
}
return {
// Stacks this function's information.
onCodePathStart(codePath, node) {
let methodName = null;
if (TARGET_NODE_TYPE.test(node.type)) {
methodName = getArrayMethodName(node);
}
funcInfo = {
arrayMethodName: methodName,
upper: funcInfo,
codePath,
hasReturn: false,
shouldCheck:
methodName &&
!node.async &&
!node.generator,
node
};
},
// Pops this function's information.
onCodePathEnd() {
funcInfo = funcInfo.upper;
},
// Checks the return statement is valid.
ReturnStatement(node) {
if (!funcInfo.shouldCheck) {
return;
}
funcInfo.hasReturn = true;
let messageId = null;
if (funcInfo.arrayMethodName === "forEach") {
// if checkForEach: true, returning a value at any path inside a forEach is not allowed
if (options.checkForEach && node.argument) {
messageId = "expectedNoReturnValue";
}
} else {
// if allowImplicit: false, should also check node.argument
if (!options.allowImplicit && !node.argument) {
messageId = "expectedReturnValue";
}
}
if (messageId) {
context.report({
node,
messageId,
data: {
name: astUtils.getFunctionNameWithKind(funcInfo.node),
arrayMethodName: fullMethodName(funcInfo.arrayMethodName)
}
});
}
},
// Reports a given function if the last path is reachable.
"FunctionExpression:exit": checkLastSegment,
"ArrowFunctionExpression:exit": checkLastSegment
};
}
};