"use strict"; var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) { if (k2 === undefined) k2 = k; var desc = Object.getOwnPropertyDescriptor(m, k); 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 (mod) { if (mod && mod.__esModule) return mod; var result = {}; if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k); __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"); const messageBase = 'Promises must be awaited, end with a call to .catch, or end with a call to .then with a rejection handler.'; const messageBaseVoid = 'Promises must be awaited, end with a call to .catch, end with a call to .then with a rejection handler' + ' or be explicitly marked as ignored with the `void` operator.'; const messageRejectionHandler = 'A rejection handler that is not a function will be ignored.'; const messagePromiseArray = "An array of Promises may be unintentional. Consider handling the promises' fulfillment or rejection with Promise.all or similar."; const messagePromiseArrayVoid = "An array of Promises may be unintentional. Consider handling the promises' fulfillment or rejection with Promise.all or similar," + ' or explicitly marking the expression as ignored with the `void` operator.'; exports.default = (0, util_1.createRule)({ name: 'no-floating-promises', meta: { docs: { description: 'Require Promise-like statements to be handled appropriately', recommended: 'recommended', requiresTypeChecking: true, }, hasSuggestions: true, messages: { floating: messageBase, floatingFixAwait: 'Add await operator.', floatingVoid: messageBaseVoid, floatingFixVoid: 'Add void operator to ignore.', floatingUselessRejectionHandler: messageBase + ' ' + messageRejectionHandler, floatingUselessRejectionHandlerVoid: messageBaseVoid + ' ' + messageRejectionHandler, floatingPromiseArray: messagePromiseArray, floatingPromiseArrayVoid: messagePromiseArrayVoid, }, schema: [ { type: 'object', properties: { ignoreVoid: { description: 'Whether to ignore `void` expressions.', type: 'boolean', }, ignoreIIFE: { description: 'Whether to ignore async IIFEs (Immediately Invoked Function Expressions).', type: 'boolean', }, }, additionalProperties: false, }, ], type: 'problem', }, defaultOptions: [ { ignoreVoid: true, ignoreIIFE: false, }, ], create(context, [options]) { const services = (0, util_1.getParserServices)(context); const checker = services.program.getTypeChecker(); return { ExpressionStatement(node) { if (options.ignoreIIFE && isAsyncIife(node)) { return; } let expression = node.expression; if (expression.type === utils_1.AST_NODE_TYPES.ChainExpression) { expression = expression.expression; } const { isUnhandled, nonFunctionHandler, promiseArray } = isUnhandledPromise(checker, expression); if (isUnhandled) { if (promiseArray) { context.report({ node, messageId: options.ignoreVoid ? 'floatingPromiseArrayVoid' : 'floatingPromiseArray', }); } else if (options.ignoreVoid) { context.report({ node, messageId: nonFunctionHandler ? 'floatingUselessRejectionHandlerVoid' : 'floatingVoid', suggest: [ { messageId: 'floatingFixVoid', fix(fixer) { const tsNode = services.esTreeNodeToTSNodeMap.get(node.expression); if (isHigherPrecedenceThanUnary(tsNode)) { return fixer.insertTextBefore(node, 'void '); } return [ fixer.insertTextBefore(node, 'void ('), fixer.insertTextAfterRange([expression.range[1], expression.range[1]], ')'), ]; }, }, ], }); } else { context.report({ node, messageId: nonFunctionHandler ? 'floatingUselessRejectionHandler' : 'floating', suggest: [ { messageId: 'floatingFixAwait', fix(fixer) { if (expression.type === utils_1.AST_NODE_TYPES.UnaryExpression && expression.operator === 'void') { return fixer.replaceTextRange([expression.range[0], expression.range[0] + 4], 'await'); } const tsNode = services.esTreeNodeToTSNodeMap.get(node.expression); if (isHigherPrecedenceThanUnary(tsNode)) { return fixer.insertTextBefore(node, 'await '); } return [ fixer.insertTextBefore(node, 'await ('), fixer.insertTextAfterRange([expression.range[1], expression.range[1]], ')'), ]; }, }, ], }); } } }, }; function isHigherPrecedenceThanUnary(node) { const operator = ts.isBinaryExpression(node) ? node.operatorToken.kind : ts.SyntaxKind.Unknown; const nodePrecedence = (0, util_1.getOperatorPrecedence)(node.kind, operator); return nodePrecedence > util_1.OperatorPrecedence.Unary; } function isAsyncIife(node) { if (node.expression.type !== utils_1.AST_NODE_TYPES.CallExpression) { return false; } return (node.expression.callee.type === utils_1.AST_NODE_TYPES.ArrowFunctionExpression || node.expression.callee.type === utils_1.AST_NODE_TYPES.FunctionExpression); } function isValidRejectionHandler(rejectionHandler) { return (services.program .getTypeChecker() .getTypeAtLocation(services.esTreeNodeToTSNodeMap.get(rejectionHandler)) .getCallSignatures().length > 0); } function isUnhandledPromise(checker, node) { // First, check expressions whose resulting types may not be promise-like if (node.type === utils_1.AST_NODE_TYPES.SequenceExpression) { // Any child in a comma expression could return a potentially unhandled // promise, so we check them all regardless of whether the final returned // value is promise-like. return (node.expressions .map(item => isUnhandledPromise(checker, item)) .find(result => result.isUnhandled) ?? { isUnhandled: false }); } if (!options.ignoreVoid && node.type === utils_1.AST_NODE_TYPES.UnaryExpression && node.operator === 'void') { // Similarly, a `void` expression always returns undefined, so we need to // see what's inside it without checking the type of the overall expression. return isUnhandledPromise(checker, node.argument); } const tsNode = services.esTreeNodeToTSNodeMap.get(node); // Check the type. At this point it can't be unhandled if it isn't a promise // or array thereof. if (isPromiseArray(checker, tsNode)) { return { isUnhandled: true, promiseArray: true }; } if (!isPromiseLike(checker, tsNode)) { return { isUnhandled: false }; } if (node.type === utils_1.AST_NODE_TYPES.CallExpression) { // If the outer expression is a call, a `.catch()` or `.then()` with // rejection handler handles the promise. const catchRejectionHandler = getRejectionHandlerFromCatchCall(node); if (catchRejectionHandler) { if (isValidRejectionHandler(catchRejectionHandler)) { return { isUnhandled: false }; } return { isUnhandled: true, nonFunctionHandler: true }; } const thenRejectionHandler = getRejectionHandlerFromThenCall(node); if (thenRejectionHandler) { if (isValidRejectionHandler(thenRejectionHandler)) { return { isUnhandled: false }; } return { isUnhandled: true, nonFunctionHandler: true }; } // `x.finally()` is transparent to resolution of the promise, so check `x`. // ("object" in this context is the `x` in `x.finally()`) const promiseFinallyObject = getObjectFromFinallyCall(node); if (promiseFinallyObject) { return isUnhandledPromise(checker, promiseFinallyObject); } // All other cases are unhandled. return { isUnhandled: true }; } else if (node.type === utils_1.AST_NODE_TYPES.ConditionalExpression) { // We must be getting the promise-like value from one of the branches of the // ternary. Check them directly. const alternateResult = isUnhandledPromise(checker, node.alternate); if (alternateResult.isUnhandled) { return alternateResult; } return isUnhandledPromise(checker, node.consequent); } else if (node.type === utils_1.AST_NODE_TYPES.MemberExpression || node.type === utils_1.AST_NODE_TYPES.Identifier || node.type === utils_1.AST_NODE_TYPES.NewExpression) { // If it is just a property access chain or a `new` call (e.g. `foo.bar` or // `new Promise()`), the promise is not handled because it doesn't have the // necessary then/catch call at the end of the chain. return { isUnhandled: true }; } else if (node.type === utils_1.AST_NODE_TYPES.LogicalExpression) { const leftResult = isUnhandledPromise(checker, node.left); if (leftResult.isUnhandled) { return leftResult; } return isUnhandledPromise(checker, node.right); } // We conservatively return false for all other types of expressions because // we don't want to accidentally fail if the promise is handled internally but // we just can't tell. return { isUnhandled: false }; } }, }); function isPromiseArray(checker, node) { const type = checker.getTypeAtLocation(node); for (const ty of tsutils .unionTypeParts(type) .map(t => checker.getApparentType(t))) { if (checker.isArrayType(ty)) { const arrayType = checker.getTypeArguments(ty)[0]; if (isPromiseLike(checker, node, arrayType)) { return true; } } if (checker.isTupleType(ty)) { for (const tupleElementType of checker.getTypeArguments(ty)) { if (isPromiseLike(checker, node, tupleElementType)) { return true; } } } } return false; } // Modified from tsutils.isThenable() to only consider thenables which can be // rejected/caught via a second parameter. Original source (MIT licensed): // // https://github.com/ajafff/tsutils/blob/49d0d31050b44b81e918eae4fbaf1dfe7b7286af/util/type.ts#L95-L125 function isPromiseLike(checker, node, type) { type ??= checker.getTypeAtLocation(node); for (const ty of tsutils.unionTypeParts(checker.getApparentType(type))) { const then = ty.getProperty('then'); if (then === undefined) { continue; } const thenType = checker.getTypeOfSymbolAtLocation(then, node); if (hasMatchingSignature(thenType, signature => signature.parameters.length >= 2 && isFunctionParam(checker, signature.parameters[0], node) && isFunctionParam(checker, signature.parameters[1], node))) { return true; } } return false; } function hasMatchingSignature(type, matcher) { for (const t of tsutils.unionTypeParts(type)) { if (t.getCallSignatures().some(matcher)) { return true; } } return false; } function isFunctionParam(checker, param, node) { const type = checker.getApparentType(checker.getTypeOfSymbolAtLocation(param, node)); for (const t of tsutils.unionTypeParts(type)) { if (t.getCallSignatures().length !== 0) { return true; } } return false; } function getRejectionHandlerFromCatchCall(expression) { if (expression.callee.type === utils_1.AST_NODE_TYPES.MemberExpression && expression.callee.property.type === utils_1.AST_NODE_TYPES.Identifier && expression.callee.property.name === 'catch' && expression.arguments.length >= 1) { return expression.arguments[0]; } return undefined; } function getRejectionHandlerFromThenCall(expression) { if (expression.callee.type === utils_1.AST_NODE_TYPES.MemberExpression && expression.callee.property.type === utils_1.AST_NODE_TYPES.Identifier && expression.callee.property.name === 'then' && expression.arguments.length >= 2) { return expression.arguments[1]; } return undefined; } function getObjectFromFinallyCall(expression) { return expression.callee.type === utils_1.AST_NODE_TYPES.MemberExpression && expression.callee.property.type === utils_1.AST_NODE_TYPES.Identifier && expression.callee.property.name === 'finally' ? expression.callee.object : undefined; } //# sourceMappingURL=no-floating-promises.js.map