@typescript-eslint/eslint-plugin
Version:
TypeScript plugin for ESLint
224 lines (223 loc) • 10.5 kB
JavaScript
;
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Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
o["default"] = v;
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var __importStar = (this && this.__importStar) || (function () {
var ownKeys = function(o) {
ownKeys = Object.getOwnPropertyNames || function (o) {
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return result;
};
})();
Object.defineProperty(exports, "__esModule", { value: true });
const utils_1 = require("@typescript-eslint/utils");
const tsutils = __importStar(require("ts-api-utils"));
const util_1 = require("../util");
const getForStatementHeadLoc_1 = require("../util/getForStatementHeadLoc");
const isPromiseAggregatorMethod_1 = require("../util/isPromiseAggregatorMethod");
exports.default = (0, util_1.createRule)({
name: 'await-thenable',
meta: {
type: 'problem',
docs: {
description: 'Disallow awaiting a value that is not a Thenable',
recommended: 'recommended',
requiresTypeChecking: true,
},
hasSuggestions: true,
messages: {
await: 'Unexpected `await` of a non-Promise (non-"Thenable") value.',
awaitUsingOfNonAsyncDisposable: 'Unexpected `await using` of a value that is not async disposable.',
convertToOrdinaryFor: 'Convert to an ordinary `for...of` loop.',
forAwaitOfNonAsyncIterable: 'Unexpected `for await...of` of a value that is not async iterable.',
invalidPromiseAggregatorInput: 'Unexpected iterable of non-Promise (non-"Thenable") values passed to promise aggregator.',
removeAwait: 'Remove unnecessary `await`.',
},
schema: [],
},
defaultOptions: [],
create(context) {
const services = (0, util_1.getParserServices)(context);
const checker = services.program.getTypeChecker();
return {
AwaitExpression(node) {
const awaitArgumentEsNode = node.argument;
const awaitArgumentType = services.getTypeAtLocation(awaitArgumentEsNode);
const awaitArgumentTsNode = services.esTreeNodeToTSNodeMap.get(awaitArgumentEsNode);
const certainty = (0, util_1.needsToBeAwaited)(checker, awaitArgumentTsNode, awaitArgumentType);
if (certainty === util_1.Awaitable.Never) {
context.report({
node,
messageId: 'await',
suggest: [
{
messageId: 'removeAwait',
fix(fixer) {
const awaitKeyword = (0, util_1.nullThrows)(context.sourceCode.getFirstToken(node, util_1.isAwaitKeyword), util_1.NullThrowsReasons.MissingToken('await', 'await expression'));
return fixer.remove(awaitKeyword);
},
},
],
});
}
},
CallExpression(node) {
if (!(0, isPromiseAggregatorMethod_1.isPromiseAggregatorMethod)(context, services, node)) {
return;
}
const argument = node.arguments.at(0);
if (argument == null) {
return;
}
if (argument.type === utils_1.TSESTree.AST_NODE_TYPES.ArrayExpression) {
for (const element of argument.elements) {
if (element == null) {
continue;
}
const type = (0, util_1.getConstrainedTypeAtLocation)(services, element);
const tsNode = services.esTreeNodeToTSNodeMap.get(element);
if (containsNonAwaitableType(type, tsNode, checker)) {
context.report({
node: element,
messageId: 'invalidPromiseAggregatorInput',
});
}
}
return;
}
const type = (0, util_1.getConstrainedTypeAtLocation)(services, argument);
if (isInvalidPromiseAggregatorInput(checker, services.esTreeNodeToTSNodeMap.get(argument), type)) {
context.report({
node: argument,
messageId: 'invalidPromiseAggregatorInput',
});
}
},
'ForOfStatement[await=true]'(node) {
const type = services.getTypeAtLocation(node.right);
if ((0, util_1.isTypeAnyType)(type)) {
return;
}
const hasAsyncIteratorSymbol = tsutils
.unionConstituents(type)
.some(typePart => tsutils.getWellKnownSymbolPropertyOfType(typePart, 'asyncIterator', checker) != null);
if (!hasAsyncIteratorSymbol) {
context.report({
loc: (0, getForStatementHeadLoc_1.getForStatementHeadLoc)(context.sourceCode, node),
messageId: 'forAwaitOfNonAsyncIterable',
suggest: [
// Note that this suggestion causes broken code for sync iterables
// of promises, since the loop variable is not awaited.
{
messageId: 'convertToOrdinaryFor',
fix(fixer) {
const awaitToken = (0, util_1.nullThrows)(context.sourceCode.getFirstToken(node, util_1.isAwaitKeyword), util_1.NullThrowsReasons.MissingToken('await', 'for await loop'));
return fixer.remove(awaitToken);
},
},
],
});
}
},
'VariableDeclaration[kind="await using"]'(node) {
for (const declarator of node.declarations) {
const init = declarator.init;
if (init == null) {
continue;
}
const type = services.getTypeAtLocation(init);
if ((0, util_1.isTypeAnyType)(type)) {
continue;
}
const hasAsyncDisposeSymbol = tsutils
.unionConstituents(type)
.some(typePart => tsutils.getWellKnownSymbolPropertyOfType(typePart, 'asyncDispose', checker) != null);
if (!hasAsyncDisposeSymbol) {
context.report({
node: init,
messageId: 'awaitUsingOfNonAsyncDisposable',
// let the user figure out what to do if there's
// await using a = b, c = d, e = f;
// it's rare and not worth the complexity to handle.
...(0, util_1.getFixOrSuggest)({
fixOrSuggest: node.declarations.length === 1 ? 'suggest' : 'none',
suggestion: {
messageId: 'removeAwait',
fix(fixer) {
const awaitToken = (0, util_1.nullThrows)(context.sourceCode.getFirstToken(node, util_1.isAwaitKeyword), util_1.NullThrowsReasons.MissingToken('await', 'await using'));
return fixer.remove(awaitToken);
},
},
}),
});
}
}
},
};
},
});
function isInvalidPromiseAggregatorInput(checker, node, type) {
// non array/tuple/iterable types already show up as a type error
if (!isIterable(type, checker)) {
return false;
}
for (const part of tsutils.unionConstituents(type)) {
const valueTypes = getValueTypesOfArrayLike(part, checker);
if (valueTypes != null) {
for (const typeArgument of valueTypes) {
if (containsNonAwaitableType(typeArgument, node, checker)) {
return true;
}
}
}
}
return false;
}
function getValueTypesOfArrayLike(type, checker) {
if (checker.isTupleType(type)) {
return checker.getTypeArguments(type);
}
if (checker.isArrayLikeType(type)) {
return [
(0, util_1.nullThrows)(type.getNumberIndexType(), 'number index type should exist on an array-like'),
];
}
// `Iterable<...>`
if (tsutils.isTypeReference(type)) {
return checker.getTypeArguments(type).slice(0, 1);
}
return null;
}
function containsNonAwaitableType(type, node, checker) {
return tsutils
.unionConstituents(type)
.some(typeArgumentPart => (0, util_1.needsToBeAwaited)(checker, node, typeArgumentPart) === util_1.Awaitable.Never);
}
function isIterable(type, checker) {
return tsutils
.unionConstituents(type)
.every(part => !!tsutils.getWellKnownSymbolPropertyOfType(part, 'iterator', checker));
}