@typescript-eslint/eslint-plugin
Version:
TypeScript plugin for ESLint
332 lines (331 loc) • 14.3 kB
JavaScript
"use strict";
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
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if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
desc = { enumerable: true, get: function() { return m[k]; } };
}
Object.defineProperty(o, k2, desc);
}) : (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
o[k2] = m[k];
}));
var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
o["default"] = v;
});
var __importStar = (this && this.__importStar) || (function () {
var ownKeys = function(o) {
ownKeys = Object.getOwnPropertyNames || function (o) {
var ar = [];
for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
return ar;
};
return ownKeys(o);
};
return function (mod) {
if (mod && mod.__esModule) return mod;
var result = {};
if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
__setModuleDefault(result, mod);
return result;
};
})();
Object.defineProperty(exports, "__esModule", { value: true });
const utils_1 = require("@typescript-eslint/utils");
const tsutils = __importStar(require("ts-api-utils"));
const ts = __importStar(require("typescript"));
const util_1 = require("../util");
/**
* Static methods on these globals are either not `this`-aware or supported being
* called without `this`.
*
* - `Promise` is not in the list because it supports subclassing by using `this`
* - `Array` is in the list because although it supports subclassing, the `this`
* value defaults to `Array` when unbound
*
* This is now a language-design invariant: static methods are never `this`-aware
* because TC39 wants to make `array.map(Class.method)` work!
*/
const SUPPORTED_GLOBALS = [
'Number',
'Object',
'String', // eslint-disable-line @typescript-eslint/internal/prefer-ast-types-enum
'RegExp',
'Symbol',
'Array',
'Proxy',
'Date',
'Atomics',
'Reflect',
'console',
'Math',
'JSON',
'Intl',
];
const nativelyBoundMembers = new Set(SUPPORTED_GLOBALS.flatMap(namespace => {
if (!(namespace in global)) {
// node.js might not have namespaces like Intl depending on compilation options
// https://nodejs.org/api/intl.html#intl_options_for_building_node_js
return [];
}
const object = global[namespace];
return Object.getOwnPropertyNames(object)
.filter(name => !name.startsWith('_') &&
typeof object[name] === 'function')
.map(name => `${namespace}.${name}`);
}));
const SUPPORTED_GLOBAL_TYPES = [
'NumberConstructor',
'ObjectConstructor',
'StringConstructor',
'SymbolConstructor',
'ArrayConstructor',
'Array',
'ProxyConstructor',
'Console',
'DateConstructor',
'Atomics',
'Math',
'JSON',
];
const isNotImported = (symbol, currentSourceFile) => {
const { valueDeclaration } = symbol;
if (!valueDeclaration) {
// working around https://github.com/microsoft/TypeScript/issues/31294
return false;
}
return (!!currentSourceFile &&
currentSourceFile !== valueDeclaration.getSourceFile());
};
const BASE_MESSAGE = 'Avoid referencing unbound methods which may cause unintentional scoping of `this`.';
exports.default = (0, util_1.createRule)({
name: 'unbound-method',
meta: {
type: 'problem',
docs: {
description: 'Enforce unbound methods are called with their expected scope',
recommended: 'recommended',
requiresTypeChecking: true,
},
messages: {
unbound: BASE_MESSAGE,
unboundWithoutThisAnnotation: `${BASE_MESSAGE}\nIf your function does not access \`this\`, you can annotate it with \`this: void\`, or consider using an arrow function instead.`,
},
schema: [
{
type: 'object',
additionalProperties: false,
properties: {
ignoreStatic: {
type: 'boolean',
description: 'Whether to skip checking whether `static` methods are correctly bound.',
},
},
},
],
},
defaultOptions: [
{
ignoreStatic: false,
},
],
create(context, [{ ignoreStatic }]) {
const services = (0, util_1.getParserServices)(context);
const currentSourceFile = services.program.getSourceFile(context.filename);
function checkIfMethodAndReport(node, symbol) {
if (!symbol) {
return false;
}
const { dangerous, firstParamIsThis } = checkIfMethod(symbol, ignoreStatic);
if (dangerous) {
context.report({
node,
messageId: firstParamIsThis === false
? 'unboundWithoutThisAnnotation'
: 'unbound',
});
return true;
}
return false;
}
function isNativelyBound(object, property) {
// We can't rely entirely on the type-level checks made at the end of this
// function, because sometimes type declarations don't come from the
// default library, but come from, for example, "@types/node". And we can't
// tell if a method is unbound just by looking at its signature declared in
// the interface.
//
// See related discussion https://github.com/typescript-eslint/typescript-eslint/pull/8952#discussion_r1576543310
if (object.type === utils_1.AST_NODE_TYPES.Identifier &&
property.type === utils_1.AST_NODE_TYPES.Identifier) {
const objectSymbol = services.getSymbolAtLocation(object);
const notImported = objectSymbol != null &&
isNotImported(objectSymbol, currentSourceFile);
if (notImported &&
nativelyBoundMembers.has(`${object.name}.${property.name}`)) {
return true;
}
}
// if `${object.name}.${property.name}` doesn't match any of
// the nativelyBoundMembers, then we fallback to type-level checks
return ((0, util_1.isBuiltinSymbolLike)(services.program, services.getTypeAtLocation(object), SUPPORTED_GLOBAL_TYPES) &&
(0, util_1.isSymbolFromDefaultLibrary)(services.program, services.getTypeAtLocation(property).getSymbol()));
}
return {
MemberExpression(node) {
if (isSafeUse(node) || isNativelyBound(node.object, node.property)) {
return;
}
checkIfMethodAndReport(node, services.getSymbolAtLocation(node));
},
ObjectPattern(node) {
if (isNodeInsideTypeDeclaration(node)) {
return;
}
let initNode = null;
if (node.parent.type === utils_1.AST_NODE_TYPES.VariableDeclarator) {
initNode = node.parent.init;
}
else if (node.parent.type === utils_1.AST_NODE_TYPES.AssignmentPattern ||
node.parent.type === utils_1.AST_NODE_TYPES.AssignmentExpression) {
initNode = node.parent.right;
}
for (const property of node.properties) {
if (property.type !== utils_1.AST_NODE_TYPES.Property ||
property.key.type !== utils_1.AST_NODE_TYPES.Identifier) {
continue;
}
if (initNode) {
if (!isNativelyBound(initNode, property.key)) {
const reported = checkIfMethodAndReport(property.key, services
.getTypeAtLocation(initNode)
.getProperty(property.key.name));
if (reported) {
continue;
}
// In assignment patterns, we should also check the type of
// Foo's nativelyBound method because initNode might be used as
// default value:
// function ({ nativelyBound }: Foo = NativeObject) {}
}
else if (node.parent.type !== utils_1.AST_NODE_TYPES.AssignmentPattern) {
continue;
}
}
for (const intersectionPart of tsutils
.unionConstituents(services.getTypeAtLocation(node))
.flatMap(unionPart => tsutils.intersectionConstituents(unionPart))) {
const reported = checkIfMethodAndReport(property.key, intersectionPart.getProperty(property.key.name));
if (reported) {
break;
}
}
}
},
};
},
});
function isNodeInsideTypeDeclaration(node) {
let parent = node;
while ((parent = parent.parent)) {
if ((parent.type === utils_1.AST_NODE_TYPES.ClassDeclaration && parent.declare) ||
parent.type === utils_1.AST_NODE_TYPES.TSAbstractMethodDefinition ||
parent.type === utils_1.AST_NODE_TYPES.TSDeclareFunction ||
parent.type === utils_1.AST_NODE_TYPES.TSFunctionType ||
parent.type === utils_1.AST_NODE_TYPES.TSInterfaceDeclaration ||
parent.type === utils_1.AST_NODE_TYPES.TSTypeAliasDeclaration ||
(parent.type === utils_1.AST_NODE_TYPES.VariableDeclaration && parent.declare)) {
return true;
}
}
return false;
}
function checkIfMethod(symbol, ignoreStatic) {
const { valueDeclaration } = symbol;
if (!valueDeclaration) {
// working around https://github.com/microsoft/TypeScript/issues/31294
return { dangerous: false };
}
switch (valueDeclaration.kind) {
case ts.SyntaxKind.PropertyDeclaration:
return {
dangerous: valueDeclaration.initializer?.kind ===
ts.SyntaxKind.FunctionExpression,
};
case ts.SyntaxKind.PropertyAssignment: {
const assignee = valueDeclaration.initializer;
if (assignee.kind !== ts.SyntaxKind.FunctionExpression) {
return {
dangerous: false,
};
}
return checkMethod(assignee, ignoreStatic);
}
case ts.SyntaxKind.MethodDeclaration:
case ts.SyntaxKind.MethodSignature: {
return checkMethod(valueDeclaration, ignoreStatic);
}
}
return { dangerous: false };
}
function checkMethod(valueDeclaration, ignoreStatic) {
const firstParam = valueDeclaration.parameters.at(0);
const firstParamIsThis = firstParam?.name.kind === ts.SyntaxKind.Identifier &&
// eslint-disable-next-line @typescript-eslint/no-unsafe-enum-comparison
firstParam.name.escapedText === 'this';
const thisArgIsVoid = firstParamIsThis && firstParam.type?.kind === ts.SyntaxKind.VoidKeyword;
return {
dangerous: !thisArgIsVoid &&
!(ignoreStatic &&
tsutils.includesModifier((0, util_1.getModifiers)(valueDeclaration), ts.SyntaxKind.StaticKeyword)),
firstParamIsThis,
};
}
function isSafeUse(node) {
const parent = node.parent;
switch (parent?.type) {
case utils_1.AST_NODE_TYPES.IfStatement:
case utils_1.AST_NODE_TYPES.ForStatement:
case utils_1.AST_NODE_TYPES.MemberExpression:
case utils_1.AST_NODE_TYPES.SwitchStatement:
case utils_1.AST_NODE_TYPES.UpdateExpression:
case utils_1.AST_NODE_TYPES.WhileStatement:
return true;
case utils_1.AST_NODE_TYPES.CallExpression:
return parent.callee === node;
case utils_1.AST_NODE_TYPES.ConditionalExpression:
return parent.test === node;
case utils_1.AST_NODE_TYPES.TaggedTemplateExpression:
return parent.tag === node;
case utils_1.AST_NODE_TYPES.UnaryExpression:
// the first case is safe for obvious
// reasons. The second one is also fine
// since we're returning something falsy
return ['!', 'delete', 'typeof', 'void'].includes(parent.operator);
case utils_1.AST_NODE_TYPES.BinaryExpression:
return ['!=', '!==', '==', '===', 'instanceof'].includes(parent.operator);
case utils_1.AST_NODE_TYPES.AssignmentExpression:
return (parent.operator === '=' &&
(node === parent.left ||
(node.type === utils_1.AST_NODE_TYPES.MemberExpression &&
node.object.type === utils_1.AST_NODE_TYPES.Super &&
parent.left.type === utils_1.AST_NODE_TYPES.MemberExpression &&
parent.left.object.type === utils_1.AST_NODE_TYPES.ThisExpression)));
case utils_1.AST_NODE_TYPES.ChainExpression:
case utils_1.AST_NODE_TYPES.TSNonNullExpression:
case utils_1.AST_NODE_TYPES.TSAsExpression:
case utils_1.AST_NODE_TYPES.TSTypeAssertion:
return isSafeUse(parent);
case utils_1.AST_NODE_TYPES.LogicalExpression:
if (parent.operator === '&&' && parent.left === node) {
// this is safe, as && will return the left if and only if it's falsy
return true;
}
// in all other cases, it's likely the logical expression will return the method ref
// so make sure the parent is a safe usage
return isSafeUse(parent);
}
return false;
}