blob: 3bdbc095a2f7b62569d2765873617cbb248f052e [file] [log] [blame]
"use strict";
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
if (k2 === undefined) k2 = k;
Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
}) : (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 experimental_utils_1 = require("@typescript-eslint/experimental-utils");
const tsutils = __importStar(require("tsutils"));
const util = __importStar(require("../util"));
exports.default = util.createRule({
name: 'require-await',
meta: {
type: 'suggestion',
docs: {
description: 'Disallow async functions which have no `await` expression',
category: 'Best Practices',
recommended: 'error',
requiresTypeChecking: true,
extendsBaseRule: true,
},
schema: [],
messages: {
missingAwait: "{{name}} has no 'await' expression.",
},
},
defaultOptions: [],
create(context) {
const parserServices = util.getParserServices(context);
const checker = parserServices.program.getTypeChecker();
const sourceCode = context.getSourceCode();
let scopeInfo = null;
/**
* Push the scope info object to the stack.
*/
function enterFunction(node) {
scopeInfo = {
upper: scopeInfo,
hasAwait: false,
hasAsync: node.async,
isGen: node.generator || false,
isAsyncYield: false,
};
}
/**
* Pop the top scope info object from the stack.
* Also, it reports the function if needed.
*/
function exitFunction(node) {
/* istanbul ignore if */ if (!scopeInfo) {
// this shouldn't ever happen, as we have to exit a function after we enter it
return;
}
if (node.async &&
!scopeInfo.hasAwait &&
!isEmptyFunction(node) &&
!(scopeInfo.isGen && scopeInfo.isAsyncYield)) {
context.report({
node,
loc: getFunctionHeadLoc(node, sourceCode),
messageId: 'missingAwait',
data: {
name: util.upperCaseFirst(util.getFunctionNameWithKind(node)),
},
});
}
scopeInfo = scopeInfo.upper;
}
/**
* Checks if the node returns a thenable type
*/
function isThenableType(node) {
const type = checker.getTypeAtLocation(node);
return tsutils.isThenableType(checker, node, type);
}
/**
* Marks the current scope as having an await
*/
function markAsHasAwait() {
if (!scopeInfo) {
return;
}
scopeInfo.hasAwait = true;
}
/**
* mark `scopeInfo.isAsyncYield` to `true` if its a generator
* function and the delegate is `true`
*/
function markAsHasDelegateGen(node) {
var _a;
if (!scopeInfo || !scopeInfo.isGen || !node.argument) {
return;
}
if (((_a = node === null || node === void 0 ? void 0 : node.argument) === null || _a === void 0 ? void 0 : _a.type) === experimental_utils_1.AST_NODE_TYPES.Literal) {
// making this `false` as for literals we don't need to check the definition
// eg : async function* run() { yield* 1 }
scopeInfo.isAsyncYield = false;
}
const tsNode = parserServices.esTreeNodeToTSNodeMap.get(node === null || node === void 0 ? void 0 : node.argument);
const type = checker.getTypeAtLocation(tsNode);
const symbol = type.getSymbol();
// async function* test1() {yield* asyncGenerator() }
if ((symbol === null || symbol === void 0 ? void 0 : symbol.getName()) === 'AsyncGenerator') {
scopeInfo.isAsyncYield = true;
}
}
return {
FunctionDeclaration: enterFunction,
FunctionExpression: enterFunction,
ArrowFunctionExpression: enterFunction,
'FunctionDeclaration:exit': exitFunction,
'FunctionExpression:exit': exitFunction,
'ArrowFunctionExpression:exit': exitFunction,
AwaitExpression: markAsHasAwait,
'ForOfStatement[await = true]': markAsHasAwait,
'YieldExpression[delegate = true]': markAsHasDelegateGen,
// check body-less async arrow function.
// ignore `async () => await foo` because it's obviously correct
'ArrowFunctionExpression[async = true] > :not(BlockStatement, AwaitExpression)'(node) {
const expression = parserServices.esTreeNodeToTSNodeMap.get(node);
if (expression && isThenableType(expression)) {
markAsHasAwait();
}
},
ReturnStatement(node) {
// short circuit early to avoid unnecessary type checks
if (!scopeInfo || scopeInfo.hasAwait || !scopeInfo.hasAsync) {
return;
}
const { expression } = parserServices.esTreeNodeToTSNodeMap.get(node);
if (expression && isThenableType(expression)) {
markAsHasAwait();
}
},
};
},
});
function isEmptyFunction(node) {
var _a;
return (((_a = node.body) === null || _a === void 0 ? void 0 : _a.type) === experimental_utils_1.AST_NODE_TYPES.BlockStatement &&
node.body.body.length === 0);
}
// https://github.com/eslint/eslint/blob/03a69dbe86d5b5768a310105416ae726822e3c1c/lib/rules/utils/ast-utils.js#L382-L392
/**
* Gets the `(` token of the given function node.
*/
function getOpeningParenOfParams(node, sourceCode) {
return util.nullThrows(node.id
? sourceCode.getTokenAfter(node.id, util.isOpeningParenToken)
: sourceCode.getFirstToken(node, util.isOpeningParenToken), util.NullThrowsReasons.MissingToken('(', node.type));
}
// https://github.com/eslint/eslint/blob/03a69dbe86d5b5768a310105416ae726822e3c1c/lib/rules/utils/ast-utils.js#L1220-L1242
/**
* Gets the location of the given function node for reporting.
*/
function getFunctionHeadLoc(node, sourceCode) {
const parent = util.nullThrows(node.parent, util.NullThrowsReasons.MissingParent);
let start = null;
let end = null;
if (node.type === experimental_utils_1.AST_NODE_TYPES.ArrowFunctionExpression) {
const arrowToken = util.nullThrows(sourceCode.getTokenBefore(node.body, util.isArrowToken), util.NullThrowsReasons.MissingToken('=>', node.type));
start = arrowToken.loc.start;
end = arrowToken.loc.end;
}
else if (parent.type === experimental_utils_1.AST_NODE_TYPES.Property ||
parent.type === experimental_utils_1.AST_NODE_TYPES.MethodDefinition) {
start = parent.loc.start;
end = getOpeningParenOfParams(node, sourceCode).loc.start;
}
else {
start = node.loc.start;
end = getOpeningParenOfParams(node, sourceCode).loc.start;
}
return {
start,
end,
};
}
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