ethers.js/packages/providers/lib.esm/base-provider.js

"use strict";
import { ForkEvent, Provider } from "@ethersproject/abstract-provider";
import { BigNumber } from "@ethersproject/bignumber";
import { arrayify, hexDataLength, hexlify, hexValue, isHexString } from "@ethersproject/bytes";
import { namehash } from "@ethersproject/hash";
import { getNetwork } from "@ethersproject/networks";
import { defineReadOnly, getStatic, resolveProperties } from "@ethersproject/properties";
import { toUtf8String } from "@ethersproject/strings";
import { poll } from "@ethersproject/web";
import { Logger } from "@ethersproject/logger";
import { version } from "./_version";
const logger = new Logger(version);
import { Formatter } from "./formatter";
//////////////////////////////
// Event Serializeing
function checkTopic(topic) {
    if (topic == null) {
        return "null";
    }
    if (hexDataLength(topic) !== 32) {
        logger.throwArgumentError("invalid topic", "topic", topic);
    }
    return topic.toLowerCase();
}
function serializeTopics(topics) {
    // Remove trailing null AND-topics; they are redundant
    topics = topics.slice();
    while (topics[topics.length - 1] == null) {
        topics.pop();
    }
    return topics.map((topic) => {
        if (Array.isArray(topic)) {
            // Only track unique OR-topics
            let unique = {};
            topic.forEach((topic) => {
                unique[checkTopic(topic)] = true;
            });
            // The order of OR-topics does not matter
            let sorted = Object.keys(unique);
            sorted.sort();
            return sorted.join("|");
        }
        else {
            return checkTopic(topic);
        }
    }).join("&");
}
function deserializeTopics(data) {
    return data.split(/&/g).map((topic) => {
        return topic.split("|").map((topic) => {
            return ((topic === "null") ? null : topic);
        });
    });
}
function getEventTag(eventName) {
    if (typeof (eventName) === "string") {
        eventName = eventName.toLowerCase();
        if (hexDataLength(eventName) === 32) {
            return "tx:" + eventName;
        }
        if (eventName.indexOf(":") === -1) {
            return eventName;
        }
    }
    else if (Array.isArray(eventName)) {
        return "filter:*:" + serializeTopics(eventName);
    }
    else if (ForkEvent.isForkEvent(eventName)) {
        logger.warn("not implemented");
        throw new Error("not implemented");
    }
    else if (eventName && typeof (eventName) === "object") {
        return "filter:" + (eventName.address || "*") + ":" + serializeTopics(eventName.topics || []);
    }
    throw new Error("invalid event - " + eventName);
}
//////////////////////////////
// Helper Object
function getTime() {
    return (new Date()).getTime();
}
//////////////////////////////
// Provider Object
/**
 *  EventType
 *   - "block"
 *   - "pending"
 *   - "error"
 *   - filter
 *   - topics array
 *   - transaction hash
 */
class Event {
    constructor(tag, listener, once) {
        defineReadOnly(this, "tag", tag);
        defineReadOnly(this, "listener", listener);
        defineReadOnly(this, "once", once);
    }
    pollable() {
        return (this.tag.indexOf(":") >= 0 || this.tag === "block" || this.tag === "pending");
    }
}
let defaultFormatter = null;
let nextPollId = 1;
export class BaseProvider extends Provider {
    constructor(network) {
        logger.checkNew(new.target, Provider);
        super();
        this.formatter = new.target.getFormatter();
        if (network instanceof Promise) {
            defineReadOnly(this, "ready", network.then((network) => {
                defineReadOnly(this, "_network", network);
                return network;
            }));
            // Squash any "unhandled promise" errors; that do not need to be handled
            this.ready.catch((error) => { });
        }
        else {
            let knownNetwork = getStatic((new.target), "getNetwork")(network);
            if (knownNetwork) {
                defineReadOnly(this, "_network", knownNetwork);
                defineReadOnly(this, "ready", Promise.resolve(this._network));
            }
            else {
                logger.throwArgumentError("invalid network", "network", network);
            }
        }
        this._lastBlockNumber = -2;
        // Events being listened to
        this._events = [];
        this._pollingInterval = 4000;
        this._emitted = { block: -2 };
        this._fastQueryDate = 0;
    }
    static getFormatter() {
        if (defaultFormatter == null) {
            defaultFormatter = new Formatter();
        }
        return defaultFormatter;
    }
    static getNetwork(network) {
        return getNetwork((network == null) ? "homestead" : network);
    }
    poll() {
        let pollId = nextPollId++;
        this.emit("willPoll", pollId);
        // Track all running promises, so we can trigger a post-poll once they are complete
        let runners = [];
        this.getBlockNumber().then((blockNumber) => {
            this._setFastBlockNumber(blockNumber);
            // If the block has not changed, meh.
            if (blockNumber === this._lastBlockNumber) {
                return;
            }
            // First polling cycle, trigger a "block" events
            if (this._emitted.block === -2) {
                this._emitted.block = blockNumber - 1;
            }
            // Notify all listener for each block that has passed
            for (let i = this._emitted.block + 1; i <= blockNumber; i++) {
                this.emit("block", i);
            }
            // The emitted block was updated, check for obsolete events
            if (this._emitted.block !== blockNumber) {
                this._emitted.block = blockNumber;
                Object.keys(this._emitted).forEach((key) => {
                    // The block event does not expire
                    if (key === "block") {
                        return;
                    }
                    // The block we were at when we emitted this event
                    let eventBlockNumber = this._emitted[key];
                    // We cannot garbage collect pending transactions or blocks here
                    // They should be garbage collected by the Provider when setting
                    // "pending" events
                    if (eventBlockNumber === "pending") {
                        return;
                    }
                    // Evict any transaction hashes or block hashes over 12 blocks
                    // old, since they should not return null anyways
                    if (blockNumber - eventBlockNumber > 12) {
                        delete this._emitted[key];
                    }
                });
            }
            // First polling cycle
            if (this._lastBlockNumber === -2) {
                this._lastBlockNumber = blockNumber - 1;
            }
            // Find all transaction hashes we are waiting on
            this._events.forEach((event) => {
                let comps = event.tag.split(":");
                switch (comps[0]) {
                    case "tx": {
                        let hash = comps[1];
                        let runner = this.getTransactionReceipt(hash).then((receipt) => {
                            if (!receipt || receipt.blockNumber == null) {
                                return null;
                            }
                            this._emitted["t:" + hash] = receipt.blockNumber;
                            this.emit(hash, receipt);
                            return null;
                        }).catch((error) => { this.emit("error", error); });
                        runners.push(runner);
                        break;
                    }
                    case "filter": {
                        let topics = deserializeTopics(comps[2]);
                        let filter = {
                            address: comps[1],
                            fromBlock: this._lastBlockNumber + 1,
                            toBlock: blockNumber,
                            topics: topics
                        };
                        if (!filter.address) {
                            delete filter.address;
                        }
                        let runner = this.getLogs(filter).then((logs) => {
                            if (logs.length === 0) {
                                return;
                            }
                            logs.forEach((log) => {
                                this._emitted["b:" + log.blockHash] = log.blockNumber;
                                this._emitted["t:" + log.transactionHash] = log.blockNumber;
                                this.emit(filter, log);
                            });
                            return null;
                        }).catch((error) => { this.emit("error", error); });
                        runners.push(runner);
                        break;
                    }
                }
            });
            this._lastBlockNumber = blockNumber;
            return null;
        }).catch((error) => { });
        Promise.all(runners).then(() => {
            this.emit("didPoll", pollId);
        });
    }
    resetEventsBlock(blockNumber) {
        this._lastBlockNumber = blockNumber - 1;
        if (this.polling) {
            this.poll();
        }
    }
    get network() {
        return this._network;
    }
    getNetwork() {
        return this.ready;
    }
    get blockNumber() {
        return this._fastBlockNumber;
    }
    get polling() {
        return (this._poller != null);
    }
    set polling(value) {
        setTimeout(() => {
            if (value && !this._poller) {
                this._poller = setInterval(this.poll.bind(this), this.pollingInterval);
            }
            else if (!value && this._poller) {
                clearInterval(this._poller);
                this._poller = null;
            }
        }, 0);
    }
    get pollingInterval() {
        return this._pollingInterval;
    }
    set pollingInterval(value) {
        if (typeof (value) !== "number" || value <= 0 || parseInt(String(value)) != value) {
            throw new Error("invalid polling interval");
        }
        this._pollingInterval = value;
        if (this._poller) {
            clearInterval(this._poller);
            this._poller = setInterval(() => { this.poll(); }, this._pollingInterval);
        }
    }
    _getFastBlockNumber() {
        let now = getTime();
        // Stale block number, request a newer value
        if ((now - this._fastQueryDate) > 2 * this._pollingInterval) {
            this._fastQueryDate = now;
            this._fastBlockNumberPromise = this.getBlockNumber().then((blockNumber) => {
                if (this._fastBlockNumber == null || blockNumber > this._fastBlockNumber) {
                    this._fastBlockNumber = blockNumber;
                }
                return this._fastBlockNumber;
            });
        }
        return this._fastBlockNumberPromise;
    }
    _setFastBlockNumber(blockNumber) {
        // Older block, maybe a stale request
        if (this._fastBlockNumber != null && blockNumber < this._fastBlockNumber) {
            return;
        }
        // Update the time we updated the blocknumber
        this._fastQueryDate = getTime();
        // Newer block number, use  it
        if (this._fastBlockNumber == null || blockNumber > this._fastBlockNumber) {
            this._fastBlockNumber = blockNumber;
            this._fastBlockNumberPromise = Promise.resolve(blockNumber);
        }
    }
    // @TODO: Add .poller which must be an event emitter with a 'start', 'stop' and 'block' event;
    //        this will be used once we move to the WebSocket or other alternatives to polling
    waitForTransaction(transactionHash, confirmations) {
        if (confirmations == null) {
            confirmations = 1;
        }
        if (confirmations === 0) {
            return this.getTransactionReceipt(transactionHash);
        }
        return new Promise((resolve) => {
            let handler = (receipt) => {
                if (receipt.confirmations < confirmations) {
                    return;
                }
                this.removeListener(transactionHash, handler);
                resolve(receipt);
            };
            this.on(transactionHash, handler);
        });
    }
    _runPerform(method, params) {
        return this.ready.then(() => {
            // Execute all the functions now that we are "ready"
            Object.keys(params).forEach((key) => {
                params[key] = params[key]();
            });
            return resolveProperties(params).then((params) => {
                return this.perform(method, params);
            });
        });
    }
    getBlockNumber() {
        return this._runPerform("getBlockNumber", {}).then((result) => {
            let value = parseInt(result);
            if (value != result) {
                throw new Error("invalid response - getBlockNumber");
            }
            this._setFastBlockNumber(value);
            return value;
        });
    }
    getGasPrice() {
        return this._runPerform("getGasPrice", {}).then((result) => {
            return BigNumber.from(result);
        });
    }
    getBalance(addressOrName, blockTag) {
        return this._runPerform("getBalance", {
            address: () => this._getAddress(addressOrName),
            blockTag: () => this._getBlockTag(blockTag)
        }).then((result) => {
            return BigNumber.from(result);
        });
    }
    getTransactionCount(addressOrName, blockTag) {
        return this._runPerform("getTransactionCount", {
            address: () => this._getAddress(addressOrName),
            blockTag: () => this._getBlockTag(blockTag)
        }).then((result) => {
            return BigNumber.from(result).toNumber();
        });
    }
    getCode(addressOrName, blockTag) {
        return this._runPerform("getCode", {
            address: () => this._getAddress(addressOrName),
            blockTag: () => this._getBlockTag(blockTag)
        }).then((result) => {
            return hexlify(result);
        });
    }
    getStorageAt(addressOrName, position, blockTag) {
        return this._runPerform("getStorageAt", {
            address: () => this._getAddress(addressOrName),
            blockTag: () => this._getBlockTag(blockTag),
            position: () => Promise.resolve(position).then((p) => hexValue(p))
        }).then((result) => {
            return hexlify(result);
        });
    }
    // This should be called by any subclass wrapping a TransactionResponse
    _wrapTransaction(tx, hash) {
        if (hash != null && hexDataLength(hash) !== 32) {
            throw new Error("invalid response - sendTransaction");
        }
        let result = tx;
        // Check the hash we expect is the same as the hash the server reported
        if (hash != null && tx.hash !== hash) {
            logger.throwError("Transaction hash mismatch from Provider.sendTransaction.", Logger.errors.UNKNOWN_ERROR, { expectedHash: tx.hash, returnedHash: hash });
        }
        // @TODO: (confirmations? number, timeout? number)
        result.wait = (confirmations) => {
            // We know this transaction *must* exist (whether it gets mined is
            // another story), so setting an emitted value forces us to
            // wait even if the node returns null for the receipt
            if (confirmations !== 0) {
                this._emitted["t:" + tx.hash] = "pending";
            }
            return this.waitForTransaction(tx.hash, confirmations).then((receipt) => {
                if (receipt == null && confirmations === 0) {
                    return null;
                }
                // No longer pending, allow the polling loop to garbage collect this
                this._emitted["t:" + tx.hash] = receipt.blockNumber;
                if (receipt.status === 0) {
                    logger.throwError("transaction failed", Logger.errors.CALL_EXCEPTION, {
                        transactionHash: tx.hash,
                        transaction: tx,
                        receipt: receipt
                    });
                }
                return receipt;
            });
        };
        return result;
    }
    sendTransaction(signedTransaction) {
        return this._runPerform("sendTransaction", {
            signedTransaction: () => Promise.resolve(signedTransaction).then(t => hexlify(t))
        }).then((result) => {
            return this._wrapTransaction(this.formatter.transaction(signedTransaction), result);
        }, (error) => {
            error.transaction = this.formatter.transaction(signedTransaction);
            if (error.transaction.hash) {
                error.transactionHash = error.transaction.hash;
            }
            throw error;
        });
    }
    _getTransactionRequest(transaction) {
        return Promise.resolve(transaction).then((t) => {
            let tx = {};
            ["from", "to"].forEach((key) => {
                if (t[key] == null) {
                    return;
                }
                tx[key] = Promise.resolve(t[key]).then(a => (a ? this._getAddress(a) : null));
            });
            ["data", "gasLimit", "gasPrice", "value"].forEach((key) => {
                if (t[key] == null) {
                    return;
                }
                tx[key] = t[key];
            });
            return resolveProperties(tx).then((t) => this.formatter.transactionRequest(t));
        });
    }
    _getFilter(filter) {
        return Promise.resolve(filter).then((f) => {
            let filter = {};
            if (f.address != null) {
                filter.address = this._getAddress(f.address);
            }
            if (f.topics) {
                filter.topics = f.topics;
            }
            if (f.blockHash != null) {
                filter.blockHash = f.blockHash;
            }
            ["fromBlock", "toBlock"].forEach((key) => {
                if (f[key] == null) {
                    return;
                }
                filter[key] = this._getBlockTag(f[key]);
            });
            return resolveProperties(filter).then((f) => this.formatter.filter(f));
        });
    }
    call(transaction, blockTag) {
        return this._runPerform("call", {
            transaction: () => this._getTransactionRequest(transaction),
            blockTag: () => this._getBlockTag(blockTag)
        }).then((result) => {
            return hexlify(result);
        });
    }
    estimateGas(transaction) {
        return this._runPerform("estimateGas", {
            transaction: () => this._getTransactionRequest(transaction)
        }).then((result) => {
            return BigNumber.from(result);
        });
    }
    _getAddress(addressOrName) {
        return this.resolveName(addressOrName).then((address) => {
            if (address == null) {
                logger.throwError("ENS name not configured", Logger.errors.UNSUPPORTED_OPERATION, {
                    operation: `resolveName(${JSON.stringify(addressOrName)})`
                });
            }
            return address;
        });
    }
    _getBlock(blockHashOrBlockTag, includeTransactions) {
        if (blockHashOrBlockTag instanceof Promise) {
            return blockHashOrBlockTag.then((b) => this._getBlock(b, includeTransactions));
        }
        return this.ready.then(() => {
            let blockHashOrBlockTagPromise = null;
            if (isHexString(blockHashOrBlockTag, 32)) {
                blockHashOrBlockTagPromise = Promise.resolve(blockHashOrBlockTag);
            }
            else {
                blockHashOrBlockTagPromise = this._getBlockTag(blockHashOrBlockTag);
            }
            return blockHashOrBlockTagPromise.then((blockHashOrBlockTag) => {
                let params = {
                    includeTransactions: !!includeTransactions
                };
                // Exactly one of blockHash or blockTag will be set
                let blockHash = null;
                let blockTag = null;
                // If blockTag is a number (not "latest", etc), this is the block number
                let blockNumber = -128;
                if (isHexString(blockHashOrBlockTag, 32)) {
                    params.blockHash = blockHashOrBlockTag;
                }
                else {
                    try {
                        params.blockTag = this.formatter.blockTag(blockHashOrBlockTag);
                        if (isHexString(params.blockTag)) {
                            blockNumber = parseInt(params.blockTag.substring(2), 16);
                        }
                    }
                    catch (error) {
                        logger.throwArgumentError("invalid block hash or block tag", "blockHashOrBlockTag", blockHashOrBlockTag);
                    }
                }
                return poll(() => {
                    return this.perform("getBlock", params).then((block) => {
                        // Block was not found
                        if (block == null) {
                            // For blockhashes, if we didn't say it existed, that blockhash may
                            // not exist. If we did see it though, perhaps from a log, we know
                            // it exists, and this node is just not caught up yet.
                            if (blockHash) {
                                if (this._emitted["b:" + blockHash] == null) {
                                    return null;
                                }
                            }
                            // For block tags, if we are asking for a future block, we return null
                            if (blockTag) {
                                if (blockNumber > this._emitted.block) {
                                    return null;
                                }
                            }
                            // Retry on the next block
                            return undefined;
                        }
                        // Add transactions
                        if (includeTransactions) {
                            return this.formatter.blockWithTransactions(block);
                        }
                        return this.formatter.block(block);
                    });
                }, { onceBlock: this });
            });
        });
    }
    getBlock(blockHashOrBlockTag) {
        return (this._getBlock(blockHashOrBlockTag, false));
    }
    getBlockWithTransactions(blockHashOrBlockTag) {
        return (this._getBlock(blockHashOrBlockTag, true));
    }
    getTransaction(transactionHash) {
        return this.ready.then(() => {
            return resolveProperties({ transactionHash: transactionHash }).then(({ transactionHash }) => {
                let params = { transactionHash: this.formatter.hash(transactionHash, true) };
                return poll(() => {
                    return this.perform("getTransaction", params).then((result) => {
                        if (result == null) {
                            if (this._emitted["t:" + transactionHash] == null) {
                                return null;
                            }
                            return undefined;
                        }
                        let tx = this.formatter.transactionResponse(result);
                        if (tx.blockNumber == null) {
                            tx.confirmations = 0;
                        }
                        else if (tx.confirmations == null) {
                            return this._getFastBlockNumber().then((blockNumber) => {
                                // Add the confirmations using the fast block number (pessimistic)
                                let confirmations = (blockNumber - tx.blockNumber) + 1;
                                if (confirmations <= 0) {
                                    confirmations = 1;
                                }
                                tx.confirmations = confirmations;
                                return this._wrapTransaction(tx);
                            });
                        }
                        return this._wrapTransaction(tx);
                    });
                }, { onceBlock: this });
            });
        });
    }
    getTransactionReceipt(transactionHash) {
        return this.ready.then(() => {
            return resolveProperties({ transactionHash: transactionHash }).then(({ transactionHash }) => {
                let params = { transactionHash: this.formatter.hash(transactionHash, true) };
                return poll(() => {
                    return this.perform("getTransactionReceipt", params).then((result) => {
                        if (result == null) {
                            if (this._emitted["t:" + transactionHash] == null) {
                                return null;
                            }
                            return undefined;
                        }
                        // "geth-etc" returns receipts before they are ready
                        if (result.blockHash == null) {
                            return undefined;
                        }
                        let receipt = this.formatter.receipt(result);
                        if (receipt.blockNumber == null) {
                            receipt.confirmations = 0;
                        }
                        else if (receipt.confirmations == null) {
                            return this._getFastBlockNumber().then((blockNumber) => {
                                // Add the confirmations using the fast block number (pessimistic)
                                let confirmations = (blockNumber - receipt.blockNumber) + 1;
                                if (confirmations <= 0) {
                                    confirmations = 1;
                                }
                                receipt.confirmations = confirmations;
                                return receipt;
                            });
                        }
                        return receipt;
                    });
                }, { onceBlock: this });
            });
        });
    }
    getLogs(filter) {
        return this._runPerform("getLogs", {
            filter: () => this._getFilter(filter)
        }).then((result) => {
            return Formatter.arrayOf(this.formatter.filterLog.bind(this.formatter))(result);
        });
    }
    getEtherPrice() {
        return this._runPerform("getEtherPrice", {}).then((result) => {
            return result;
        });
    }
    _getBlockTag(blockTag) {
        if (blockTag instanceof Promise) {
            return blockTag.then((b) => this._getBlockTag(b));
        }
        if (typeof (blockTag) === "number" && blockTag < 0) {
            if (blockTag % 1) {
                logger.throwArgumentError("invalid BlockTag", "blockTag", blockTag);
            }
            return this._getFastBlockNumber().then((bn) => {
                bn += blockTag;
                if (bn < 0) {
                    bn = 0;
                }
                return this.formatter.blockTag(bn);
            });
        }
        return Promise.resolve(this.formatter.blockTag(blockTag));
    }
    _getResolver(name) {
        // Get the resolver from the blockchain
        return this.getNetwork().then((network) => {
            // No ENS...
            if (!network.ensAddress) {
                logger.throwError("network does not support ENS", Logger.errors.UNSUPPORTED_OPERATION, { operation: "ENS", network: network.name });
            }
            // keccak256("resolver(bytes32)")
            let data = "0x0178b8bf" + namehash(name).substring(2);
            let transaction = { to: network.ensAddress, data: data };
            return this.call(transaction).then((data) => {
                return this.formatter.callAddress(data);
            });
        });
    }
    resolveName(name) {
        // If it is a promise, resolve it then recurse
        if (name instanceof Promise) {
            return name.then((addressOrName) => this.resolveName(addressOrName));
        }
        // If it is already an address, nothing to resolve
        try {
            return Promise.resolve(this.formatter.address(name));
        }
        catch (error) { }
        // Get the addr from the resovler
        return this._getResolver(name).then((resolverAddress) => {
            if (!resolverAddress) {
                return null;
            }
            // keccak256("addr(bytes32)")
            let data = "0x3b3b57de" + namehash(name).substring(2);
            let transaction = { to: resolverAddress, data: data };
            return this.call(transaction).then((data) => {
                return this.formatter.callAddress(data);
            });
        });
    }
    lookupAddress(address) {
        if (address instanceof Promise) {
            return address.then((address) => this.lookupAddress(address));
        }
        address = this.formatter.address(address);
        let name = address.substring(2) + ".addr.reverse";
        return this._getResolver(name).then((resolverAddress) => {
            if (!resolverAddress) {
                return null;
            }
            // keccak("name(bytes32)")
            let data = "0x691f3431" + namehash(name).substring(2);
            return this.call({ to: resolverAddress, data: data }).then((data) => {
                let bytes = arrayify(data);
                // Strip off the dynamic string pointer (0x20)
                if (bytes.length < 32 || !BigNumber.from(bytes.slice(0, 32)).eq(32)) {
                    return null;
                }
                bytes = bytes.slice(32);
                if (bytes.length < 32) {
                    return null;
                }
                let length = BigNumber.from(bytes.slice(0, 32)).toNumber();
                bytes = bytes.slice(32);
                if (length > bytes.length) {
                    return null;
                }
                let name = toUtf8String(bytes.slice(0, length));
                // Make sure the reverse record matches the foward record
                return this.resolveName(name).then((addr) => {
                    if (addr != address) {
                        return null;
                    }
                    return name;
                });
            });
        });
    }
    perform(method, params) {
        return logger.throwError(method + " not implemented", Logger.errors.NOT_IMPLEMENTED, { operation: method });
    }
    _startPending() {
        console.log("WARNING: this provider does not support pending events");
    }
    _stopPending() {
    }
    // Returns true if there are events that still require polling
    _checkPolling() {
        this.polling = (this._events.filter((e) => e.pollable()).length > 0);
    }
    _addEventListener(eventName, listener, once) {
        this._events.push(new Event(getEventTag(eventName), listener, once));
        if (eventName === "pending") {
            this._startPending();
        }
        // Do we still now have any events that require polling?
        this._checkPolling();
        return this;
    }
    on(eventName, listener) {
        return this._addEventListener(eventName, listener, false);
    }
    once(eventName, listener) {
        return this._addEventListener(eventName, listener, true);
    }
    emit(eventName, ...args) {
        let result = false;
        let eventTag = getEventTag(eventName);
        this._events = this._events.filter((event) => {
            if (event.tag !== eventTag) {
                return true;
            }
            setTimeout(() => {
                event.listener.apply(this, args);
            }, 0);
            result = true;
            return !(event.once);
        });
        // Do we still have any events that require polling? ("once" events remove themselves)
        this._checkPolling();
        return result;
    }
    listenerCount(eventName) {
        if (!eventName) {
            return this._events.length;
        }
        let eventTag = getEventTag(eventName);
        return this._events.filter((event) => {
            return (event.tag === eventTag);
        }).length;
    }
    listeners(eventName) {
        if (eventName == null) {
            return this._events.map((event) => event.listener);
        }
        let eventTag = getEventTag(eventName);
        return this._events
            .filter((event) => (event.tag === eventTag))
            .map((event) => event.listener);
    }
    off(eventName, listener) {
        if (listener == null) {
            return this.removeAllListeners(eventName);
        }
        let found = false;
        let eventTag = getEventTag(eventName);
        this._events = this._events.filter((event) => {
            if (event.tag !== eventTag || event.listener != listener) {
                return true;
            }
            if (found) {
                return true;
            }
            found = true;
            return false;
        });
        if (eventName === "pending" && this.listenerCount("pending") === 0) {
            this._stopPending();
        }
        // Do we still have any events that require polling?
        this._checkPolling();
        return this;
    }
    removeAllListeners(eventName) {
        if (eventName == null) {
            this._events = [];
            this._stopPending();
        }
        else {
            let eventTag = getEventTag(eventName);
            this._events = this._events.filter((event) => {
                return (event.tag !== eventTag);
            });
            if (eventName === "pending") {
                this._stopPending();
            }
        }
        // Do we still have any events that require polling?
        this._checkPolling();
        return this;
    }
}