168 lines
6.0 KiB
Plaintext
168 lines
6.0 KiB
Plaintext
|
"use strict";
|
||
|
Object.defineProperty(exports, "__esModule", { value: true });
|
||
|
const utils_1 = require("@typescript-eslint/utils");
|
||
|
const util_1 = require("../util");
|
||
|
const getESLintCoreRule_1 = require("../util/getESLintCoreRule");
|
||
|
const baseRule = (0, getESLintCoreRule_1.getESLintCoreRule)('no-loop-func');
|
||
|
exports.default = (0, util_1.createRule)({
|
||
|
name: 'no-loop-func',
|
||
|
meta: {
|
||
|
type: 'suggestion',
|
||
|
docs: {
|
||
|
description: 'Disallow function declarations that contain unsafe references inside loop statements',
|
||
|
extendsBaseRule: true,
|
||
|
},
|
||
|
hasSuggestions: baseRule.meta.hasSuggestions,
|
||
|
schema: [],
|
||
|
messages: baseRule.meta.messages,
|
||
|
},
|
||
|
defaultOptions: [],
|
||
|
create(context) {
|
||
|
/**
|
||
|
* Reports functions which match the following condition:
|
||
|
* - has a loop node in ancestors.
|
||
|
* - has any references which refers to an unsafe variable.
|
||
|
*
|
||
|
* @param node The AST node to check.
|
||
|
*/
|
||
|
function checkForLoops(node) {
|
||
|
const loopNode = getContainingLoopNode(node);
|
||
|
if (!loopNode) {
|
||
|
return;
|
||
|
}
|
||
|
const references = context.sourceCode.getScope(node).through;
|
||
|
const unsafeRefs = references
|
||
|
.filter(r => !isSafe(loopNode, r))
|
||
|
.map(r => r.identifier.name);
|
||
|
if (unsafeRefs.length > 0) {
|
||
|
context.report({
|
||
|
node,
|
||
|
messageId: 'unsafeRefs',
|
||
|
data: { varNames: `'${unsafeRefs.join("', '")}'` },
|
||
|
});
|
||
|
}
|
||
|
}
|
||
|
return {
|
||
|
ArrowFunctionExpression: checkForLoops,
|
||
|
FunctionExpression: checkForLoops,
|
||
|
FunctionDeclaration: checkForLoops,
|
||
|
};
|
||
|
},
|
||
|
});
|
||
|
/**
|
||
|
* Gets the containing loop node of a specified node.
|
||
|
*
|
||
|
* We don't need to check nested functions, so this ignores those.
|
||
|
* `Scope.through` contains references of nested functions.
|
||
|
*
|
||
|
* @param node An AST node to get.
|
||
|
* @returns The containing loop node of the specified node, or `null`.
|
||
|
*/
|
||
|
function getContainingLoopNode(node) {
|
||
|
for (let currentNode = node; currentNode.parent; currentNode = currentNode.parent) {
|
||
|
const parent = currentNode.parent;
|
||
|
switch (parent.type) {
|
||
|
case utils_1.AST_NODE_TYPES.WhileStatement:
|
||
|
case utils_1.AST_NODE_TYPES.DoWhileStatement:
|
||
|
return parent;
|
||
|
case utils_1.AST_NODE_TYPES.ForStatement:
|
||
|
// `init` is outside of the loop.
|
||
|
if (parent.init !== currentNode) {
|
||
|
return parent;
|
||
|
}
|
||
|
break;
|
||
|
case utils_1.AST_NODE_TYPES.ForInStatement:
|
||
|
case utils_1.AST_NODE_TYPES.ForOfStatement:
|
||
|
// `right` is outside of the loop.
|
||
|
if (parent.right !== currentNode) {
|
||
|
return parent;
|
||
|
}
|
||
|
break;
|
||
|
case utils_1.AST_NODE_TYPES.ArrowFunctionExpression:
|
||
|
case utils_1.AST_NODE_TYPES.FunctionExpression:
|
||
|
case utils_1.AST_NODE_TYPES.FunctionDeclaration:
|
||
|
// We don't need to check nested functions.
|
||
|
return null;
|
||
|
default:
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
return null;
|
||
|
}
|
||
|
/**
|
||
|
* Gets the containing loop node of a given node.
|
||
|
* If the loop was nested, this returns the most outer loop.
|
||
|
* @param node A node to get. This is a loop node.
|
||
|
* @param excludedNode A node that the result node should not include.
|
||
|
* @returns The most outer loop node.
|
||
|
*/
|
||
|
function getTopLoopNode(node, excludedNode) {
|
||
|
const border = excludedNode ? excludedNode.range[1] : 0;
|
||
|
let retv = node;
|
||
|
let containingLoopNode = node;
|
||
|
while (containingLoopNode && containingLoopNode.range[0] >= border) {
|
||
|
retv = containingLoopNode;
|
||
|
containingLoopNode = getContainingLoopNode(containingLoopNode);
|
||
|
}
|
||
|
return retv;
|
||
|
}
|
||
|
/**
|
||
|
* Checks whether a given reference which refers to an upper scope's variable is
|
||
|
* safe or not.
|
||
|
* @param loopNode A containing loop node.
|
||
|
* @param reference A reference to check.
|
||
|
* @returns `true` if the reference is safe or not.
|
||
|
*/
|
||
|
function isSafe(loopNode, reference) {
|
||
|
const variable = reference.resolved;
|
||
|
const definition = variable?.defs[0];
|
||
|
const declaration = definition?.parent;
|
||
|
const kind = declaration?.type === utils_1.AST_NODE_TYPES.VariableDeclaration
|
||
|
? declaration.kind
|
||
|
: '';
|
||
|
// type references are all safe
|
||
|
// this only really matters for global types that haven't been configured
|
||
|
if (reference.isTypeReference) {
|
||
|
return true;
|
||
|
}
|
||
|
// Variables which are declared by `const` is safe.
|
||
|
if (kind === 'const') {
|
||
|
return true;
|
||
|
}
|
||
|
/*
|
||
|
* Variables which are declared by `let` in the loop is safe.
|
||
|
* It's a different instance from the next loop step's.
|
||
|
*/
|
||
|
if (kind === 'let' &&
|
||
|
declaration &&
|
||
|
declaration.range[0] > loopNode.range[0] &&
|
||
|
declaration.range[1] < loopNode.range[1]) {
|
||
|
return true;
|
||
|
}
|
||
|
/*
|
||
|
* WriteReferences which exist after this border are unsafe because those
|
||
|
* can modify the variable.
|
||
|
*/
|
||
|
const border = getTopLoopNode(loopNode, kind === 'let' ? declaration : null)
|
||
|
.range[0];
|
||
|
/**
|
||
|
* Checks whether a given reference is safe or not.
|
||
|
* The reference is every reference of the upper scope's variable we are
|
||
|
* looking now.
|
||
|
*
|
||
|
* It's safe if the reference matches one of the following condition.
|
||
|
* - is readonly.
|
||
|
* - doesn't exist inside a local function and after the border.
|
||
|
*
|
||
|
* @param upperRef A reference to check.
|
||
|
* @returns `true` if the reference is safe.
|
||
|
*/
|
||
|
function isSafeReference(upperRef) {
|
||
|
const id = upperRef.identifier;
|
||
|
return (!upperRef.isWrite() ||
|
||
|
(variable?.scope.variableScope === upperRef.from.variableScope &&
|
||
|
id.range[0] < border));
|
||
|
}
|
||
|
return variable?.references.every(isSafeReference) ?? false;
|
||
|
}
|
||
|
//# sourceMappingURL=no-loop-func.js.map
|