@typescript-eslint/eslint-plugin/dist/rules/no-floating-promises.js

"use strict";
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    if (k2 === undefined) k2 = k;
    Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
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    if (k2 === undefined) k2 = k;
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Object.defineProperty(exports, "__esModule", { value: true });
const tsutils = __importStar(require("tsutils"));
const utils_1 = require("@typescript-eslint/utils");
const util = __importStar(require("../util"));
exports.default = util.createRule({
    name: 'no-floating-promises',
    meta: {
        docs: {
            description: 'Requires Promise-like values to be handled appropriately',
            recommended: 'error',
            suggestion: true,
            requiresTypeChecking: true,
        },
        hasSuggestions: true,
        messages: {
            floating: 'Promises must be awaited, end with a call to .catch, or end with a call to .then with a rejection handler.',
            floatingVoid: '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.',
            floatingFixVoid: 'Add void operator to ignore.',
        },
        schema: [
            {
                type: 'object',
                properties: {
                    ignoreVoid: { type: 'boolean' },
                    ignoreIIFE: { type: 'boolean' },
                },
                additionalProperties: false,
            },
        ],
        type: 'problem',
    },
    defaultOptions: [
        {
            ignoreVoid: true,
            ignoreIIFE: false,
        },
    ],
    create(context, [options]) {
        const parserServices = util.getParserServices(context);
        const checker = parserServices.program.getTypeChecker();
        const sourceCode = context.getSourceCode();
        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;
                }
                if (isUnhandledPromise(checker, expression)) {
                    if (options.ignoreVoid) {
                        context.report({
                            node,
                            messageId: 'floatingVoid',
                            suggest: [
                                {
                                    messageId: 'floatingFixVoid',
                                    fix(fixer) {
                                        let code = sourceCode.getText(node);
                                        code = `void ${code}`;
                                        return fixer.replaceText(node, code);
                                    },
                                },
                            ],
                        });
                    }
                    else {
                        context.report({
                            node,
                            messageId: 'floating',
                        });
                    }
                }
            },
        };
        function isAsyncIife(node) {
            if (node.expression.type !== utils_1.AST_NODE_TYPES.CallExpression) {
                return false;
            }
            return (node.expression.type === utils_1.AST_NODE_TYPES.CallExpression &&
                (node.expression.callee.type ===
                    utils_1.AST_NODE_TYPES.ArrowFunctionExpression ||
                    node.expression.callee.type === utils_1.AST_NODE_TYPES.FunctionExpression));
        }
        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.some(item => isUnhandledPromise(checker, item));
            }
            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);
            }
            // Check the type. At this point it can't be unhandled if it isn't a promise
            if (!isPromiseLike(checker, parserServices.esTreeNodeToTSNodeMap.get(node))) {
                return false;
            }
            if (node.type === utils_1.AST_NODE_TYPES.CallExpression) {
                // If the outer expression is a call, it must be either a `.then()` or
                // `.catch()` that handles the promise.
                return (!isPromiseCatchCallWithHandler(node) &&
                    !isPromiseThenCallWithRejectionHandler(node) &&
                    !isPromiseFinallyCallWithHandler(node));
            }
            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.
                return (isUnhandledPromise(checker, node.alternate) ||
                    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 true;
            }
            // 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 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) {
    const 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 isPromiseCatchCallWithHandler(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 === 'catch' &&
        expression.arguments.length >= 1);
}
function isPromiseThenCallWithRejectionHandler(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 === 'then' &&
        expression.arguments.length >= 2);
}
function isPromiseFinallyCallWithHandler(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.arguments.length >= 1);
}
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