diff --git a/build.js b/build.js
new file mode 100644
index 00000000..406cecb1
--- /dev/null
+++ b/build.js
@@ -0,0 +1,54 @@
+#!/usr/bin/env node
+"use strict";
+
+var fs = require("fs");
+var browserify = require("browserify");
+var timers = require("./src/fake-timers-src.js");
+
+function makeBundle(entryPoint, config, done) {
+    browserify(entryPoint, config).bundle(function(err, buffer) {
+        if (err) {
+            throw err;
+        }
+        done(buffer.toString());
+    });
+}
+
+makeBundle(
+    "./src/fake-timers-src.js",
+    {
+        standalone: "FakeTimers",
+        detectGlobals: false
+    },
+    function(bundle) {
+        fs.writeFileSync("fake-timers.js", bundle);
+    }
+);
+
+makeBundle(
+    "./src/fake-timers-esm.js",
+    {
+        detectGlobals: false
+    },
+    function(bundle) {
+        var source = "let FakeTimers;\n";
+        source += bundle;
+        source += Object.keys(timers)
+            .map(function(key) {
+                return (
+                    "const _" +
+                    key +
+                    " = FakeTimers." +
+                    key +
+                    "\nexport { _" +
+                    key +
+                    " as " +
+                    key +
+                    " };"
+                );
+            })
+            .join("\n");
+
+        fs.writeFileSync("fake-timers-esm.js", source);
+    }
+);
diff --git a/fake-timers-esm.js b/fake-timers-esm.js
new file mode 100644
index 00000000..b1c92a27
--- /dev/null
+++ b/fake-timers-esm.js
@@ -0,0 +1,1985 @@
+let FakeTimers;
+(function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){
+"use strict";
+
+var every = require("./prototypes/array").every;
+
+function hasCallsLeft(callMap, spy) {
+    if (callMap[spy.id] === undefined) {
+        callMap[spy.id] = 0;
+    }
+
+    return callMap[spy.id] < spy.callCount;
+}
+
+function checkAdjacentCalls(callMap, spy, index, spies) {
+    var calledBeforeNext = true;
+
+    if (index !== spies.length - 1) {
+        calledBeforeNext = spy.calledBefore(spies[index + 1]);
+    }
+
+    if (hasCallsLeft(callMap, spy) && calledBeforeNext) {
+        callMap[spy.id] += 1;
+        return true;
+    }
+
+    return false;
+}
+
+module.exports = function calledInOrder(spies) {
+    var callMap = {};
+    // eslint-disable-next-line no-underscore-dangle
+    var _spies = arguments.length > 1 ? arguments : spies;
+
+    return every(_spies, checkAdjacentCalls.bind(null, callMap));
+};
+
+},{"./prototypes/array":9}],2:[function(require,module,exports){
+"use strict";
+
+var functionName = require("./function-name");
+
+module.exports = function className(value) {
+    return (
+        (value.constructor && value.constructor.name) ||
+        // The next branch is for IE11 support only:
+        // Because the name property is not set on the prototype
+        // of the Function object, we finally try to grab the
+        // name from its definition. This will never be reached
+        // in node, so we are not able to test this properly.
+        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/name
+        (typeof value.constructor === "function" &&
+            /* istanbul ignore next */
+            functionName(value.constructor)) ||
+        null
+    );
+};
+
+},{"./function-name":5}],3:[function(require,module,exports){
+/* eslint-disable no-console */
+"use strict";
+
+// wrap returns a function that will invoke the supplied function and print a deprecation warning to the console each
+// time it is called.
+exports.wrap = function(func, msg) {
+    var wrapped = function() {
+        exports.printWarning(msg);
+        return func.apply(this, arguments);
+    };
+    if (func.prototype) {
+        wrapped.prototype = func.prototype;
+    }
+    return wrapped;
+};
+
+// defaultMsg returns a string which can be supplied to `wrap()` to notify the user that a particular part of the
+// sinon API has been deprecated.
+exports.defaultMsg = function(packageName, funcName) {
+    return (
+        packageName +
+        "." +
+        funcName +
+        " is deprecated and will be removed from the public API in a future version of " +
+        packageName +
+        "."
+    );
+};
+
+exports.printWarning = function(msg) {
+    // Watch out for IE7 and below! :(
+    /* istanbul ignore next */
+    if (typeof console !== "undefined") {
+        if (console.info) {
+            console.info(msg);
+        } else {
+            console.log(msg);
+        }
+    }
+};
+
+},{}],4:[function(require,module,exports){
+"use strict";
+
+// This is an `every` implementation that works for all iterables
+module.exports = function every(obj, fn) {
+    var pass = true;
+
+    try {
+        /* eslint-disable-next-line local-rules/no-prototype-methods */
+        obj.forEach(function() {
+            if (!fn.apply(this, arguments)) {
+                // Throwing an error is the only way to break `forEach`
+                throw new Error();
+            }
+        });
+    } catch (e) {
+        pass = false;
+    }
+
+    return pass;
+};
+
+},{}],5:[function(require,module,exports){
+"use strict";
+
+module.exports = function functionName(func) {
+    if (!func) {
+        return "";
+    }
+
+    return (
+        func.displayName ||
+        func.name ||
+        // Use function decomposition as a last resort to get function
+        // name. Does not rely on function decomposition to work - if it
+        // doesn't debugging will be slightly less informative
+        // (i.e. toString will say 'spy' rather than 'myFunc').
+        (String(func).match(/function ([^\s(]+)/) || [])[1]
+    );
+};
+
+},{}],6:[function(require,module,exports){
+"use strict";
+
+var globalObject;
+/* istanbul ignore else */
+if (typeof global !== "undefined") {
+    // Node
+    globalObject = global;
+} else if (typeof window !== "undefined") {
+    // Browser
+    globalObject = window;
+} else {
+    // WebWorker
+    globalObject = self;
+}
+
+module.exports = globalObject;
+
+},{}],7:[function(require,module,exports){
+"use strict";
+
+module.exports = {
+    global: require("./global"),
+    calledInOrder: require("./called-in-order"),
+    className: require("./class-name"),
+    deprecated: require("./deprecated"),
+    every: require("./every"),
+    functionName: require("./function-name"),
+    orderByFirstCall: require("./order-by-first-call"),
+    prototypes: require("./prototypes"),
+    typeOf: require("./type-of"),
+    valueToString: require("./value-to-string")
+};
+
+},{"./called-in-order":1,"./class-name":2,"./deprecated":3,"./every":4,"./function-name":5,"./global":6,"./order-by-first-call":8,"./prototypes":12,"./type-of":17,"./value-to-string":18}],8:[function(require,module,exports){
+"use strict";
+
+var sort = require("./prototypes/array").sort;
+var slice = require("./prototypes/array").slice;
+
+function comparator(a, b) {
+    // uuid, won't ever be equal
+    var aCall = a.getCall(0);
+    var bCall = b.getCall(0);
+    var aId = (aCall && aCall.callId) || -1;
+    var bId = (bCall && bCall.callId) || -1;
+
+    return aId < bId ? -1 : 1;
+}
+
+module.exports = function orderByFirstCall(spies) {
+    return sort(slice(spies), comparator);
+};
+
+},{"./prototypes/array":9}],9:[function(require,module,exports){
+"use strict";
+
+var copyPrototype = require("./copy-prototype");
+
+module.exports = copyPrototype(Array.prototype);
+
+},{"./copy-prototype":10}],10:[function(require,module,exports){
+"use strict";
+
+var call = Function.call;
+
+module.exports = function copyPrototypeMethods(prototype) {
+    /* eslint-disable local-rules/no-prototype-methods */
+    return Object.getOwnPropertyNames(prototype).reduce(function(result, name) {
+        // ignore size because it throws from Map
+        if (
+            name !== "size" &&
+            name !== "caller" &&
+            name !== "callee" &&
+            name !== "arguments" &&
+            typeof prototype[name] === "function"
+        ) {
+            result[name] = call.bind(prototype[name]);
+        }
+
+        return result;
+    }, Object.create(null));
+};
+
+},{}],11:[function(require,module,exports){
+"use strict";
+
+var copyPrototype = require("./copy-prototype");
+
+module.exports = copyPrototype(Function.prototype);
+
+},{"./copy-prototype":10}],12:[function(require,module,exports){
+"use strict";
+
+module.exports = {
+    array: require("./array"),
+    function: require("./function"),
+    map: require("./map"),
+    object: require("./object"),
+    set: require("./set"),
+    string: require("./string")
+};
+
+},{"./array":9,"./function":11,"./map":13,"./object":14,"./set":15,"./string":16}],13:[function(require,module,exports){
+"use strict";
+
+var copyPrototype = require("./copy-prototype");
+
+module.exports = copyPrototype(Map.prototype);
+
+},{"./copy-prototype":10}],14:[function(require,module,exports){
+"use strict";
+
+var copyPrototype = require("./copy-prototype");
+
+module.exports = copyPrototype(Object.prototype);
+
+},{"./copy-prototype":10}],15:[function(require,module,exports){
+"use strict";
+
+var copyPrototype = require("./copy-prototype");
+
+module.exports = copyPrototype(Set.prototype);
+
+},{"./copy-prototype":10}],16:[function(require,module,exports){
+"use strict";
+
+var copyPrototype = require("./copy-prototype");
+
+module.exports = copyPrototype(String.prototype);
+
+},{"./copy-prototype":10}],17:[function(require,module,exports){
+"use strict";
+
+var type = require("type-detect");
+
+module.exports = function typeOf(value) {
+    return type(value).toLowerCase();
+};
+
+},{"type-detect":19}],18:[function(require,module,exports){
+"use strict";
+
+function valueToString(value) {
+    if (value && value.toString) {
+        /* eslint-disable-next-line local-rules/no-prototype-methods */
+        return value.toString();
+    }
+    return String(value);
+}
+
+module.exports = valueToString;
+
+},{}],19:[function(require,module,exports){
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
+	typeof define === 'function' && define.amd ? define(factory) :
+	(global.typeDetect = factory());
+}(this, (function () { 'use strict';
+
+/* !
+ * type-detect
+ * Copyright(c) 2013 jake luer <jake@alogicalparadox.com>
+ * MIT Licensed
+ */
+var promiseExists = typeof Promise === 'function';
+
+/* eslint-disable no-undef */
+var globalObject = typeof self === 'object' ? self : global; // eslint-disable-line id-blacklist
+
+var symbolExists = typeof Symbol !== 'undefined';
+var mapExists = typeof Map !== 'undefined';
+var setExists = typeof Set !== 'undefined';
+var weakMapExists = typeof WeakMap !== 'undefined';
+var weakSetExists = typeof WeakSet !== 'undefined';
+var dataViewExists = typeof DataView !== 'undefined';
+var symbolIteratorExists = symbolExists && typeof Symbol.iterator !== 'undefined';
+var symbolToStringTagExists = symbolExists && typeof Symbol.toStringTag !== 'undefined';
+var setEntriesExists = setExists && typeof Set.prototype.entries === 'function';
+var mapEntriesExists = mapExists && typeof Map.prototype.entries === 'function';
+var setIteratorPrototype = setEntriesExists && Object.getPrototypeOf(new Set().entries());
+var mapIteratorPrototype = mapEntriesExists && Object.getPrototypeOf(new Map().entries());
+var arrayIteratorExists = symbolIteratorExists && typeof Array.prototype[Symbol.iterator] === 'function';
+var arrayIteratorPrototype = arrayIteratorExists && Object.getPrototypeOf([][Symbol.iterator]());
+var stringIteratorExists = symbolIteratorExists && typeof String.prototype[Symbol.iterator] === 'function';
+var stringIteratorPrototype = stringIteratorExists && Object.getPrototypeOf(''[Symbol.iterator]());
+var toStringLeftSliceLength = 8;
+var toStringRightSliceLength = -1;
+/**
+ * ### typeOf (obj)
+ *
+ * Uses `Object.prototype.toString` to determine the type of an object,
+ * normalising behaviour across engine versions & well optimised.
+ *
+ * @param {Mixed} object
+ * @return {String} object type
+ * @api public
+ */
+function typeDetect(obj) {
+  /* ! Speed optimisation
+   * Pre:
+   *   string literal     x 3,039,035 ops/sec ±1.62% (78 runs sampled)
+   *   boolean literal    x 1,424,138 ops/sec ±4.54% (75 runs sampled)
+   *   number literal     x 1,653,153 ops/sec ±1.91% (82 runs sampled)
+   *   undefined          x 9,978,660 ops/sec ±1.92% (75 runs sampled)
+   *   function           x 2,556,769 ops/sec ±1.73% (77 runs sampled)
+   * Post:
+   *   string literal     x 38,564,796 ops/sec ±1.15% (79 runs sampled)
+   *   boolean literal    x 31,148,940 ops/sec ±1.10% (79 runs sampled)
+   *   number literal     x 32,679,330 ops/sec ±1.90% (78 runs sampled)
+   *   undefined          x 32,363,368 ops/sec ±1.07% (82 runs sampled)
+   *   function           x 31,296,870 ops/sec ±0.96% (83 runs sampled)
+   */
+  var typeofObj = typeof obj;
+  if (typeofObj !== 'object') {
+    return typeofObj;
+  }
+
+  /* ! Speed optimisation
+   * Pre:
+   *   null               x 28,645,765 ops/sec ±1.17% (82 runs sampled)
+   * Post:
+   *   null               x 36,428,962 ops/sec ±1.37% (84 runs sampled)
+   */
+  if (obj === null) {
+    return 'null';
+  }
+
+  /* ! Spec Conformance
+   * Test: `Object.prototype.toString.call(window)``
+   *  - Node === "[object global]"
+   *  - Chrome === "[object global]"
+   *  - Firefox === "[object Window]"
+   *  - PhantomJS === "[object Window]"
+   *  - Safari === "[object Window]"
+   *  - IE 11 === "[object Window]"
+   *  - IE Edge === "[object Window]"
+   * Test: `Object.prototype.toString.call(this)``
+   *  - Chrome Worker === "[object global]"
+   *  - Firefox Worker === "[object DedicatedWorkerGlobalScope]"
+   *  - Safari Worker === "[object DedicatedWorkerGlobalScope]"
+   *  - IE 11 Worker === "[object WorkerGlobalScope]"
+   *  - IE Edge Worker === "[object WorkerGlobalScope]"
+   */
+  if (obj === globalObject) {
+    return 'global';
+  }
+
+  /* ! Speed optimisation
+   * Pre:
+   *   array literal      x 2,888,352 ops/sec ±0.67% (82 runs sampled)
+   * Post:
+   *   array literal      x 22,479,650 ops/sec ±0.96% (81 runs sampled)
+   */
+  if (
+    Array.isArray(obj) &&
+    (symbolToStringTagExists === false || !(Symbol.toStringTag in obj))
+  ) {
+    return 'Array';
+  }
+
+  // Not caching existence of `window` and related properties due to potential
+  // for `window` to be unset before tests in quasi-browser environments.
+  if (typeof window === 'object' && window !== null) {
+    /* ! Spec Conformance
+     * (https://html.spec.whatwg.org/multipage/browsers.html#location)
+     * WhatWG HTML$7.7.3 - The `Location` interface
+     * Test: `Object.prototype.toString.call(window.location)``
+     *  - IE <=11 === "[object Object]"
+     *  - IE Edge <=13 === "[object Object]"
+     */
+    if (typeof window.location === 'object' && obj === window.location) {
+      return 'Location';
+    }
+
+    /* ! Spec Conformance
+     * (https://html.spec.whatwg.org/#document)
+     * WhatWG HTML$3.1.1 - The `Document` object
+     * Note: Most browsers currently adher to the W3C DOM Level 2 spec
+     *       (https://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-26809268)
+     *       which suggests that browsers should use HTMLTableCellElement for
+     *       both TD and TH elements. WhatWG separates these.
+     *       WhatWG HTML states:
+     *         > For historical reasons, Window objects must also have a
+     *         > writable, configurable, non-enumerable property named
+     *         > HTMLDocument whose value is the Document interface object.
+     * Test: `Object.prototype.toString.call(document)``
+     *  - Chrome === "[object HTMLDocument]"
+     *  - Firefox === "[object HTMLDocument]"
+     *  - Safari === "[object HTMLDocument]"
+     *  - IE <=10 === "[object Document]"
+     *  - IE 11 === "[object HTMLDocument]"
+     *  - IE Edge <=13 === "[object HTMLDocument]"
+     */
+    if (typeof window.document === 'object' && obj === window.document) {
+      return 'Document';
+    }
+
+    if (typeof window.navigator === 'object') {
+      /* ! Spec Conformance
+       * (https://html.spec.whatwg.org/multipage/webappapis.html#mimetypearray)
+       * WhatWG HTML$8.6.1.5 - Plugins - Interface MimeTypeArray
+       * Test: `Object.prototype.toString.call(navigator.mimeTypes)``
+       *  - IE <=10 === "[object MSMimeTypesCollection]"
+       */
+      if (typeof window.navigator.mimeTypes === 'object' &&
+          obj === window.navigator.mimeTypes) {
+        return 'MimeTypeArray';
+      }
+
+      /* ! Spec Conformance
+       * (https://html.spec.whatwg.org/multipage/webappapis.html#pluginarray)
+       * WhatWG HTML$8.6.1.5 - Plugins - Interface PluginArray
+       * Test: `Object.prototype.toString.call(navigator.plugins)``
+       *  - IE <=10 === "[object MSPluginsCollection]"
+       */
+      if (typeof window.navigator.plugins === 'object' &&
+          obj === window.navigator.plugins) {
+        return 'PluginArray';
+      }
+    }
+
+    if ((typeof window.HTMLElement === 'function' ||
+        typeof window.HTMLElement === 'object') &&
+        obj instanceof window.HTMLElement) {
+      /* ! Spec Conformance
+      * (https://html.spec.whatwg.org/multipage/webappapis.html#pluginarray)
+      * WhatWG HTML$4.4.4 - The `blockquote` element - Interface `HTMLQuoteElement`
+      * Test: `Object.prototype.toString.call(document.createElement('blockquote'))``
+      *  - IE <=10 === "[object HTMLBlockElement]"
+      */
+      if (obj.tagName === 'BLOCKQUOTE') {
+        return 'HTMLQuoteElement';
+      }
+
+      /* ! Spec Conformance
+       * (https://html.spec.whatwg.org/#htmltabledatacellelement)
+       * WhatWG HTML$4.9.9 - The `td` element - Interface `HTMLTableDataCellElement`
+       * Note: Most browsers currently adher to the W3C DOM Level 2 spec
+       *       (https://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-82915075)
+       *       which suggests that browsers should use HTMLTableCellElement for
+       *       both TD and TH elements. WhatWG separates these.
+       * Test: Object.prototype.toString.call(document.createElement('td'))
+       *  - Chrome === "[object HTMLTableCellElement]"
+       *  - Firefox === "[object HTMLTableCellElement]"
+       *  - Safari === "[object HTMLTableCellElement]"
+       */
+      if (obj.tagName === 'TD') {
+        return 'HTMLTableDataCellElement';
+      }
+
+      /* ! Spec Conformance
+       * (https://html.spec.whatwg.org/#htmltableheadercellelement)
+       * WhatWG HTML$4.9.9 - The `td` element - Interface `HTMLTableHeaderCellElement`
+       * Note: Most browsers currently adher to the W3C DOM Level 2 spec
+       *       (https://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-82915075)
+       *       which suggests that browsers should use HTMLTableCellElement for
+       *       both TD and TH elements. WhatWG separates these.
+       * Test: Object.prototype.toString.call(document.createElement('th'))
+       *  - Chrome === "[object HTMLTableCellElement]"
+       *  - Firefox === "[object HTMLTableCellElement]"
+       *  - Safari === "[object HTMLTableCellElement]"
+       */
+      if (obj.tagName === 'TH') {
+        return 'HTMLTableHeaderCellElement';
+      }
+    }
+  }
+
+  /* ! Speed optimisation
+  * Pre:
+  *   Float64Array       x 625,644 ops/sec ±1.58% (80 runs sampled)
+  *   Float32Array       x 1,279,852 ops/sec ±2.91% (77 runs sampled)
+  *   Uint32Array        x 1,178,185 ops/sec ±1.95% (83 runs sampled)
+  *   Uint16Array        x 1,008,380 ops/sec ±2.25% (80 runs sampled)
+  *   Uint8Array         x 1,128,040 ops/sec ±2.11% (81 runs sampled)
+  *   Int32Array         x 1,170,119 ops/sec ±2.88% (80 runs sampled)
+  *   Int16Array         x 1,176,348 ops/sec ±5.79% (86 runs sampled)
+  *   Int8Array          x 1,058,707 ops/sec ±4.94% (77 runs sampled)
+  *   Uint8ClampedArray  x 1,110,633 ops/sec ±4.20% (80 runs sampled)
+  * Post:
+  *   Float64Array       x 7,105,671 ops/sec ±13.47% (64 runs sampled)
+  *   Float32Array       x 5,887,912 ops/sec ±1.46% (82 runs sampled)
+  *   Uint32Array        x 6,491,661 ops/sec ±1.76% (79 runs sampled)
+  *   Uint16Array        x 6,559,795 ops/sec ±1.67% (82 runs sampled)
+  *   Uint8Array         x 6,463,966 ops/sec ±1.43% (85 runs sampled)
+  *   Int32Array         x 5,641,841 ops/sec ±3.49% (81 runs sampled)
+  *   Int16Array         x 6,583,511 ops/sec ±1.98% (80 runs sampled)
+  *   Int8Array          x 6,606,078 ops/sec ±1.74% (81 runs sampled)
+  *   Uint8ClampedArray  x 6,602,224 ops/sec ±1.77% (83 runs sampled)
+  */
+  var stringTag = (symbolToStringTagExists && obj[Symbol.toStringTag]);
+  if (typeof stringTag === 'string') {
+    return stringTag;
+  }
+
+  var objPrototype = Object.getPrototypeOf(obj);
+  /* ! Speed optimisation
+  * Pre:
+  *   regex literal      x 1,772,385 ops/sec ±1.85% (77 runs sampled)
+  *   regex constructor  x 2,143,634 ops/sec ±2.46% (78 runs sampled)
+  * Post:
+  *   regex literal      x 3,928,009 ops/sec ±0.65% (78 runs sampled)
+  *   regex constructor  x 3,931,108 ops/sec ±0.58% (84 runs sampled)
+  */
+  if (objPrototype === RegExp.prototype) {
+    return 'RegExp';
+  }
+
+  /* ! Speed optimisation
+  * Pre:
+  *   date               x 2,130,074 ops/sec ±4.42% (68 runs sampled)
+  * Post:
+  *   date               x 3,953,779 ops/sec ±1.35% (77 runs sampled)
+  */
+  if (objPrototype === Date.prototype) {
+    return 'Date';
+  }
+
+  /* ! Spec Conformance
+   * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-promise.prototype-@@tostringtag)
+   * ES6$25.4.5.4 - Promise.prototype[@@toStringTag] should be "Promise":
+   * Test: `Object.prototype.toString.call(Promise.resolve())``
+   *  - Chrome <=47 === "[object Object]"
+   *  - Edge <=20 === "[object Object]"
+   *  - Firefox 29-Latest === "[object Promise]"
+   *  - Safari 7.1-Latest === "[object Promise]"
+   */
+  if (promiseExists && objPrototype === Promise.prototype) {
+    return 'Promise';
+  }
+
+  /* ! Speed optimisation
+  * Pre:
+  *   set                x 2,222,186 ops/sec ±1.31% (82 runs sampled)
+  * Post:
+  *   set                x 4,545,879 ops/sec ±1.13% (83 runs sampled)
+  */
+  if (setExists && objPrototype === Set.prototype) {
+    return 'Set';
+  }
+
+  /* ! Speed optimisation
+  * Pre:
+  *   map                x 2,396,842 ops/sec ±1.59% (81 runs sampled)
+  * Post:
+  *   map                x 4,183,945 ops/sec ±6.59% (82 runs sampled)
+  */
+  if (mapExists && objPrototype === Map.prototype) {
+    return 'Map';
+  }
+
+  /* ! Speed optimisation
+  * Pre:
+  *   weakset            x 1,323,220 ops/sec ±2.17% (76 runs sampled)
+  * Post:
+  *   weakset            x 4,237,510 ops/sec ±2.01% (77 runs sampled)
+  */
+  if (weakSetExists && objPrototype === WeakSet.prototype) {
+    return 'WeakSet';
+  }
+
+  /* ! Speed optimisation
+  * Pre:
+  *   weakmap            x 1,500,260 ops/sec ±2.02% (78 runs sampled)
+  * Post:
+  *   weakmap            x 3,881,384 ops/sec ±1.45% (82 runs sampled)
+  */
+  if (weakMapExists && objPrototype === WeakMap.prototype) {
+    return 'WeakMap';
+  }
+
+  /* ! Spec Conformance
+   * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-dataview.prototype-@@tostringtag)
+   * ES6$24.2.4.21 - DataView.prototype[@@toStringTag] should be "DataView":
+   * Test: `Object.prototype.toString.call(new DataView(new ArrayBuffer(1)))``
+   *  - Edge <=13 === "[object Object]"
+   */
+  if (dataViewExists && objPrototype === DataView.prototype) {
+    return 'DataView';
+  }
+
+  /* ! Spec Conformance
+   * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-%mapiteratorprototype%-@@tostringtag)
+   * ES6$23.1.5.2.2 - %MapIteratorPrototype%[@@toStringTag] should be "Map Iterator":
+   * Test: `Object.prototype.toString.call(new Map().entries())``
+   *  - Edge <=13 === "[object Object]"
+   */
+  if (mapExists && objPrototype === mapIteratorPrototype) {
+    return 'Map Iterator';
+  }
+
+  /* ! Spec Conformance
+   * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-%setiteratorprototype%-@@tostringtag)
+   * ES6$23.2.5.2.2 - %SetIteratorPrototype%[@@toStringTag] should be "Set Iterator":
+   * Test: `Object.prototype.toString.call(new Set().entries())``
+   *  - Edge <=13 === "[object Object]"
+   */
+  if (setExists && objPrototype === setIteratorPrototype) {
+    return 'Set Iterator';
+  }
+
+  /* ! Spec Conformance
+   * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-%arrayiteratorprototype%-@@tostringtag)
+   * ES6$22.1.5.2.2 - %ArrayIteratorPrototype%[@@toStringTag] should be "Array Iterator":
+   * Test: `Object.prototype.toString.call([][Symbol.iterator]())``
+   *  - Edge <=13 === "[object Object]"
+   */
+  if (arrayIteratorExists && objPrototype === arrayIteratorPrototype) {
+    return 'Array Iterator';
+  }
+
+  /* ! Spec Conformance
+   * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-%stringiteratorprototype%-@@tostringtag)
+   * ES6$21.1.5.2.2 - %StringIteratorPrototype%[@@toStringTag] should be "String Iterator":
+   * Test: `Object.prototype.toString.call(''[Symbol.iterator]())``
+   *  - Edge <=13 === "[object Object]"
+   */
+  if (stringIteratorExists && objPrototype === stringIteratorPrototype) {
+    return 'String Iterator';
+  }
+
+  /* ! Speed optimisation
+  * Pre:
+  *   object from null   x 2,424,320 ops/sec ±1.67% (76 runs sampled)
+  * Post:
+  *   object from null   x 5,838,000 ops/sec ±0.99% (84 runs sampled)
+  */
+  if (objPrototype === null) {
+    return 'Object';
+  }
+
+  return Object
+    .prototype
+    .toString
+    .call(obj)
+    .slice(toStringLeftSliceLength, toStringRightSliceLength);
+}
+
+return typeDetect;
+
+})));
+
+},{}],20:[function(require,module,exports){
+// eslint-disable-next-line no-undef
+FakeTimers = require("./fake-timers-src");
+
+},{"./fake-timers-src":21}],21:[function(require,module,exports){
+"use strict";
+
+var globalObject = require("@sinonjs/commons").global;
+
+// eslint-disable-next-line complexity
+function withGlobal(_global) {
+    var userAgent = _global.navigator && _global.navigator.userAgent;
+    var isRunningInIE = userAgent && userAgent.indexOf("MSIE ") > -1;
+    var maxTimeout = Math.pow(2, 31) - 1; //see https://heycam.github.io/webidl/#abstract-opdef-converttoint
+    var NOOP = function() {
+        return undefined;
+    };
+    var NOOP_ARRAY = function() {
+        return [];
+    };
+    var timeoutResult = _global.setTimeout(NOOP, 0);
+    var addTimerReturnsObject = typeof timeoutResult === "object";
+    var hrtimePresent =
+        _global.process && typeof _global.process.hrtime === "function";
+    var hrtimeBigintPresent =
+        hrtimePresent && typeof _global.process.hrtime.bigint === "function";
+    var nextTickPresent =
+        _global.process && typeof _global.process.nextTick === "function";
+    var performancePresent =
+        _global.performance && typeof _global.performance.now === "function";
+    var hasPerformancePrototype =
+        _global.Performance &&
+        (typeof _global.Performance).match(/^(function|object)$/);
+    var queueMicrotaskPresent = _global.hasOwnProperty("queueMicrotask");
+    var requestAnimationFramePresent =
+        _global.requestAnimationFrame &&
+        typeof _global.requestAnimationFrame === "function";
+    var cancelAnimationFramePresent =
+        _global.cancelAnimationFrame &&
+        typeof _global.cancelAnimationFrame === "function";
+    var requestIdleCallbackPresent =
+        _global.requestIdleCallback &&
+        typeof _global.requestIdleCallback === "function";
+    var cancelIdleCallbackPresent =
+        _global.cancelIdleCallback &&
+        typeof _global.cancelIdleCallback === "function";
+    var setImmediatePresent =
+        _global.setImmediate && typeof _global.setImmediate === "function";
+
+    // Make properties writable in IE, as per
+    // http://www.adequatelygood.com/Replacing-setTimeout-Globally.html
+    /* eslint-disable no-self-assign */
+    if (isRunningInIE) {
+        _global.setTimeout = _global.setTimeout;
+        _global.clearTimeout = _global.clearTimeout;
+        _global.setInterval = _global.setInterval;
+        _global.clearInterval = _global.clearInterval;
+        _global.Date = _global.Date;
+    }
+
+    // setImmediate is not a standard function
+    // avoid adding the prop to the window object if not present
+    if (setImmediatePresent) {
+        _global.setImmediate = _global.setImmediate;
+        _global.clearImmediate = _global.clearImmediate;
+    }
+    /* eslint-enable no-self-assign */
+
+    _global.clearTimeout(timeoutResult);
+
+    var NativeDate = _global.Date;
+    var uniqueTimerId = 1;
+
+    function isNumberFinite(num) {
+        if (Number.isFinite) {
+            return Number.isFinite(num);
+        }
+
+        if (typeof num !== "number") {
+            return false;
+        }
+
+        return isFinite(num);
+    }
+
+    /**
+     * Parse strings like "01:10:00" (meaning 1 hour, 10 minutes, 0 seconds) into
+     * number of milliseconds. This is used to support human-readable strings passed
+     * to clock.tick()
+     */
+    function parseTime(str) {
+        if (!str) {
+            return 0;
+        }
+
+        var strings = str.split(":");
+        var l = strings.length;
+        var i = l;
+        var ms = 0;
+        var parsed;
+
+        if (l > 3 || !/^(\d\d:){0,2}\d\d?$/.test(str)) {
+            throw new Error(
+                "tick only understands numbers, 'm:s' and 'h:m:s'. Each part must be two digits"
+            );
+        }
+
+        while (i--) {
+            parsed = parseInt(strings[i], 10);
+
+            if (parsed >= 60) {
+                throw new Error("Invalid time " + str);
+            }
+
+            ms += parsed * Math.pow(60, l - i - 1);
+        }
+
+        return ms * 1000;
+    }
+
+    /**
+     * Get the decimal part of the millisecond value as nanoseconds
+     *
+     * @param {Number} msFloat the number of milliseconds
+     * @returns {Number} an integer number of nanoseconds in the range [0,1e6)
+     *
+     * Example: nanoRemainer(123.456789) -> 456789
+     */
+    function nanoRemainder(msFloat) {
+        var modulo = 1e6;
+        var remainder = (msFloat * 1e6) % modulo;
+        var positiveRemainder = remainder < 0 ? remainder + modulo : remainder;
+
+        return Math.floor(positiveRemainder);
+    }
+
+    /**
+     * Used to grok the `now` parameter to createClock.
+     * @param epoch {Date|number} the system time
+     */
+    function getEpoch(epoch) {
+        if (!epoch) {
+            return 0;
+        }
+        if (typeof epoch.getTime === "function") {
+            return epoch.getTime();
+        }
+        if (typeof epoch === "number") {
+            return epoch;
+        }
+        throw new TypeError("now should be milliseconds since UNIX epoch");
+    }
+
+    function inRange(from, to, timer) {
+        return timer && timer.callAt >= from && timer.callAt <= to;
+    }
+
+    function mirrorDateProperties(target, source) {
+        var prop;
+        for (prop in source) {
+            if (source.hasOwnProperty(prop)) {
+                target[prop] = source[prop];
+            }
+        }
+
+        // set special now implementation
+        if (source.now) {
+            target.now = function now() {
+                return target.clock.now;
+            };
+        } else {
+            delete target.now;
+        }
+
+        // set special toSource implementation
+        if (source.toSource) {
+            target.toSource = function toSource() {
+                return source.toSource();
+            };
+        } else {
+            delete target.toSource;
+        }
+
+        // set special toString implementation
+        target.toString = function toString() {
+            return source.toString();
+        };
+
+        target.prototype = source.prototype;
+        target.parse = source.parse;
+        target.UTC = source.UTC;
+        target.prototype.toUTCString = source.prototype.toUTCString;
+
+        return target;
+    }
+
+    function createDate() {
+        function ClockDate(year, month, date, hour, minute, second, ms) {
+            // the Date constructor called as a function, ref Ecma-262 Edition 5.1, section 15.9.2.
+            // This remains so in the 10th edition of 2019 as well.
+            if (!(this instanceof ClockDate)) {
+                return new NativeDate(ClockDate.clock.now).toString();
+            }
+
+            // if Date is called as a constructor with 'new' keyword
+            // Defensive and verbose to avoid potential harm in passing
+            // explicit undefined when user does not pass argument
+            switch (arguments.length) {
+                case 0:
+                    return new NativeDate(ClockDate.clock.now);
+                case 1:
+                    return new NativeDate(year);
+                case 2:
+                    return new NativeDate(year, month);
+                case 3:
+                    return new NativeDate(year, month, date);
+                case 4:
+                    return new NativeDate(year, month, date, hour);
+                case 5:
+                    return new NativeDate(year, month, date, hour, minute);
+                case 6:
+                    return new NativeDate(
+                        year,
+                        month,
+                        date,
+                        hour,
+                        minute,
+                        second
+                    );
+                default:
+                    return new NativeDate(
+                        year,
+                        month,
+                        date,
+                        hour,
+                        minute,
+                        second,
+                        ms
+                    );
+            }
+        }
+
+        return mirrorDateProperties(ClockDate, NativeDate);
+    }
+
+    function enqueueJob(clock, job) {
+        // enqueues a microtick-deferred task - ecma262/#sec-enqueuejob
+        if (!clock.jobs) {
+            clock.jobs = [];
+        }
+        clock.jobs.push(job);
+    }
+
+    function runJobs(clock) {
+        // runs all microtick-deferred tasks - ecma262/#sec-runjobs
+        if (!clock.jobs) {
+            return;
+        }
+        for (var i = 0; i < clock.jobs.length; i++) {
+            var job = clock.jobs[i];
+            job.func.apply(null, job.args);
+            if (clock.loopLimit && i > clock.loopLimit) {
+                throw new Error(
+                    "Aborting after running " +
+                        clock.loopLimit +
+                        " timers, assuming an infinite loop!"
+                );
+            }
+        }
+        clock.jobs = [];
+    }
+
+    function addTimer(clock, timer) {
+        if (timer.func === undefined) {
+            throw new Error("Callback must be provided to timer calls");
+        }
+
+        timer.type = timer.immediate ? "Immediate" : "Timeout";
+
+        if (timer.hasOwnProperty("delay")) {
+            if (!isNumberFinite(timer.delay)) {
+                timer.delay = 0;
+            }
+            timer.delay = timer.delay > maxTimeout ? 1 : timer.delay;
+            timer.delay = Math.max(0, timer.delay);
+        }
+
+        if (timer.hasOwnProperty("interval")) {
+            timer.type = "Interval";
+            timer.interval = timer.interval > maxTimeout ? 1 : timer.interval;
+        }
+
+        if (timer.hasOwnProperty("animation")) {
+            timer.type = "AnimationFrame";
+            timer.animation = true;
+        }
+
+        if (!clock.timers) {
+            clock.timers = {};
+        }
+
+        timer.id = uniqueTimerId++;
+        timer.createdAt = clock.now;
+        timer.callAt =
+            clock.now + (parseInt(timer.delay) || (clock.duringTick ? 1 : 0));
+
+        clock.timers[timer.id] = timer;
+
+        if (addTimerReturnsObject) {
+            var res = {
+                id: timer.id,
+                ref: function() {
+                    return res;
+                },
+                unref: function() {
+                    return res;
+                },
+                refresh: function() {
+                    return res;
+                }
+            };
+            return res;
+        }
+
+        return timer.id;
+    }
+
+    /* eslint consistent-return: "off" */
+    function compareTimers(a, b) {
+        // Sort first by absolute timing
+        if (a.callAt < b.callAt) {
+            return -1;
+        }
+        if (a.callAt > b.callAt) {
+            return 1;
+        }
+
+        // Sort next by immediate, immediate timers take precedence
+        if (a.immediate && !b.immediate) {
+            return -1;
+        }
+        if (!a.immediate && b.immediate) {
+            return 1;
+        }
+
+        // Sort next by creation time, earlier-created timers take precedence
+        if (a.createdAt < b.createdAt) {
+            return -1;
+        }
+        if (a.createdAt > b.createdAt) {
+            return 1;
+        }
+
+        // Sort next by id, lower-id timers take precedence
+        if (a.id < b.id) {
+            return -1;
+        }
+        if (a.id > b.id) {
+            return 1;
+        }
+
+        // As timer ids are unique, no fallback `0` is necessary
+    }
+
+    function firstTimerInRange(clock, from, to) {
+        var timers = clock.timers;
+        var timer = null;
+        var id, isInRange;
+
+        for (id in timers) {
+            if (timers.hasOwnProperty(id)) {
+                isInRange = inRange(from, to, timers[id]);
+
+                if (
+                    isInRange &&
+                    (!timer || compareTimers(timer, timers[id]) === 1)
+                ) {
+                    timer = timers[id];
+                }
+            }
+        }
+
+        return timer;
+    }
+
+    function firstTimer(clock) {
+        var timers = clock.timers;
+        var timer = null;
+        var id;
+
+        for (id in timers) {
+            if (timers.hasOwnProperty(id)) {
+                if (!timer || compareTimers(timer, timers[id]) === 1) {
+                    timer = timers[id];
+                }
+            }
+        }
+
+        return timer;
+    }
+
+    function lastTimer(clock) {
+        var timers = clock.timers;
+        var timer = null;
+        var id;
+
+        for (id in timers) {
+            if (timers.hasOwnProperty(id)) {
+                if (!timer || compareTimers(timer, timers[id]) === -1) {
+                    timer = timers[id];
+                }
+            }
+        }
+
+        return timer;
+    }
+
+    function callTimer(clock, timer) {
+        if (typeof timer.interval === "number") {
+            clock.timers[timer.id].callAt += timer.interval;
+        } else {
+            delete clock.timers[timer.id];
+        }
+
+        if (typeof timer.func === "function") {
+            timer.func.apply(null, timer.args);
+        } else {
+            /* eslint no-eval: "off" */
+            eval(timer.func);
+        }
+    }
+
+    function clearTimer(clock, timerId, ttype) {
+        if (!timerId) {
+            // null appears to be allowed in most browsers, and appears to be
+            // relied upon by some libraries, like Bootstrap carousel
+            return;
+        }
+
+        if (!clock.timers) {
+            clock.timers = {};
+        }
+
+        // in Node, timerId is an object with .ref()/.unref(), and
+        // its .id field is the actual timer id.
+        var id = typeof timerId === "object" ? timerId.id : timerId;
+
+        if (clock.timers.hasOwnProperty(id)) {
+            // check that the ID matches a timer of the correct type
+            var timer = clock.timers[id];
+            if (timer.type === ttype) {
+                delete clock.timers[id];
+            } else {
+                var clear =
+                    ttype === "AnimationFrame"
+                        ? "cancelAnimationFrame"
+                        : "clear" + ttype;
+                var schedule =
+                    timer.type === "AnimationFrame"
+                        ? "requestAnimationFrame"
+                        : "set" + timer.type;
+                throw new Error(
+                    "Cannot clear timer: timer created with " +
+                        schedule +
+                        "() but cleared with " +
+                        clear +
+                        "()"
+                );
+            }
+        }
+    }
+
+    function uninstall(clock, target, config) {
+        var method, i, l;
+        var installedHrTime = "_hrtime";
+        var installedNextTick = "_nextTick";
+
+        for (i = 0, l = clock.methods.length; i < l; i++) {
+            method = clock.methods[i];
+            if (method === "hrtime" && target.process) {
+                target.process.hrtime = clock[installedHrTime];
+            } else if (method === "nextTick" && target.process) {
+                target.process.nextTick = clock[installedNextTick];
+            } else if (method === "performance") {
+                var originalPerfDescriptor = Object.getOwnPropertyDescriptor(
+                    clock,
+                    "_" + method
+                );
+                if (
+                    originalPerfDescriptor &&
+                    originalPerfDescriptor.get &&
+                    !originalPerfDescriptor.set
+                ) {
+                    Object.defineProperty(
+                        target,
+                        method,
+                        originalPerfDescriptor
+                    );
+                } else if (originalPerfDescriptor.configurable) {
+                    target[method] = clock["_" + method];
+                }
+            } else {
+                if (target[method] && target[method].hadOwnProperty) {
+                    target[method] = clock["_" + method];
+                    if (
+                        method === "clearInterval" &&
+                        config.shouldAdvanceTime === true
+                    ) {
+                        target[method](clock.attachedInterval);
+                    }
+                } else {
+                    try {
+                        delete target[method];
+                    } catch (ignore) {
+                        /* eslint no-empty: "off" */
+                    }
+                }
+            }
+        }
+
+        // Prevent multiple executions which will completely remove these props
+        clock.methods = [];
+
+        // return pending timers, to enable checking what timers remained on uninstall
+        if (!clock.timers) {
+            return [];
+        }
+        return Object.keys(clock.timers).map(function mapper(key) {
+            return clock.timers[key];
+        });
+    }
+
+    function hijackMethod(target, method, clock) {
+        var prop;
+        clock[method].hadOwnProperty = Object.prototype.hasOwnProperty.call(
+            target,
+            method
+        );
+        clock["_" + method] = target[method];
+
+        if (method === "Date") {
+            var date = mirrorDateProperties(clock[method], target[method]);
+            target[method] = date;
+        } else if (method === "performance") {
+            var originalPerfDescriptor = Object.getOwnPropertyDescriptor(
+                target,
+                method
+            );
+            // JSDOM has a read only performance field so we have to save/copy it differently
+            if (
+                originalPerfDescriptor &&
+                originalPerfDescriptor.get &&
+                !originalPerfDescriptor.set
+            ) {
+                Object.defineProperty(
+                    clock,
+                    "_" + method,
+                    originalPerfDescriptor
+                );
+
+                var perfDescriptor = Object.getOwnPropertyDescriptor(
+                    clock,
+                    method
+                );
+                Object.defineProperty(target, method, perfDescriptor);
+            } else {
+                target[method] = clock[method];
+            }
+        } else {
+            target[method] = function() {
+                return clock[method].apply(clock, arguments);
+            };
+
+            for (prop in clock[method]) {
+                if (clock[method].hasOwnProperty(prop)) {
+                    target[method][prop] = clock[method][prop];
+                }
+            }
+        }
+
+        target[method].clock = clock;
+    }
+
+    function doIntervalTick(clock, advanceTimeDelta) {
+        clock.tick(advanceTimeDelta);
+    }
+
+    var timers = {
+        setTimeout: _global.setTimeout,
+        clearTimeout: _global.clearTimeout,
+        setInterval: _global.setInterval,
+        clearInterval: _global.clearInterval,
+        Date: _global.Date
+    };
+
+    if (setImmediatePresent) {
+        timers.setImmediate = _global.setImmediate;
+        timers.clearImmediate = _global.clearImmediate;
+    }
+
+    if (hrtimePresent) {
+        timers.hrtime = _global.process.hrtime;
+    }
+
+    if (nextTickPresent) {
+        timers.nextTick = _global.process.nextTick;
+    }
+
+    if (performancePresent) {
+        timers.performance = _global.performance;
+    }
+
+    if (requestAnimationFramePresent) {
+        timers.requestAnimationFrame = _global.requestAnimationFrame;
+    }
+
+    if (queueMicrotaskPresent) {
+        timers.queueMicrotask = true;
+    }
+
+    if (cancelAnimationFramePresent) {
+        timers.cancelAnimationFrame = _global.cancelAnimationFrame;
+    }
+
+    if (requestIdleCallbackPresent) {
+        timers.requestIdleCallback = _global.requestIdleCallback;
+    }
+
+    if (cancelIdleCallbackPresent) {
+        timers.cancelIdleCallback = _global.cancelIdleCallback;
+    }
+
+    var keys =
+        Object.keys ||
+        function(obj) {
+            var ks = [];
+            var key;
+
+            for (key in obj) {
+                if (obj.hasOwnProperty(key)) {
+                    ks.push(key);
+                }
+            }
+
+            return ks;
+        };
+
+    var originalSetTimeout = _global.setImmediate || _global.setTimeout;
+
+    /**
+     * @param start {Date|number} the system time - non-integer values are floored
+     * @param loopLimit {number}  maximum number of timers that will be run when calling runAll()
+     */
+    function createClock(start, loopLimit) {
+        // eslint-disable-next-line no-param-reassign
+        start = Math.floor(getEpoch(start));
+        // eslint-disable-next-line no-param-reassign
+        loopLimit = loopLimit || 1000;
+        var nanos = 0;
+        var adjustedSystemTime = [0, 0]; // [millis, nanoremainder]
+
+        if (NativeDate === undefined) {
+            throw new Error(
+                "The global scope doesn't have a `Date` object" +
+                    " (see https://github.com/sinonjs/sinon/issues/1852#issuecomment-419622780)"
+            );
+        }
+
+        var clock = {
+            now: start,
+            timeouts: {},
+            Date: createDate(),
+            loopLimit: loopLimit
+        };
+
+        clock.Date.clock = clock;
+
+        function getTimeToNextFrame() {
+            return 16 - ((clock.now - start) % 16);
+        }
+
+        function hrtime(prev) {
+            var millisSinceStart = clock.now - adjustedSystemTime[0] - start;
+            var secsSinceStart = Math.floor(millisSinceStart / 1000);
+            var remainderInNanos =
+                (millisSinceStart - secsSinceStart * 1e3) * 1e6 +
+                nanos -
+                adjustedSystemTime[1];
+
+            if (Array.isArray(prev)) {
+                if (prev[1] > 1e9) {
+                    throw new TypeError(
+                        "Number of nanoseconds can't exceed a billion"
+                    );
+                }
+
+                var oldSecs = prev[0];
+                var nanoDiff = remainderInNanos - prev[1];
+                var secDiff = secsSinceStart - oldSecs;
+
+                if (nanoDiff < 0) {
+                    nanoDiff += 1e9;
+                    secDiff -= 1;
+                }
+
+                return [secDiff, nanoDiff];
+            }
+            return [secsSinceStart, remainderInNanos];
+        }
+
+        if (hrtimeBigintPresent) {
+            hrtime.bigint = function() {
+                var parts = hrtime();
+                return BigInt(parts[0]) * BigInt(1e9) + BigInt(parts[1]); // eslint-disable-line
+            };
+        }
+
+        clock.requestIdleCallback = function requestIdleCallback(
+            func,
+            timeout
+        ) {
+            var timeToNextIdlePeriod = 0;
+
+            if (clock.countTimers() > 0) {
+                timeToNextIdlePeriod = 50; // const for now
+            }
+
+            var result = addTimer(clock, {
+                func: func,
+                args: Array.prototype.slice.call(arguments, 2),
+                delay:
+                    typeof timeout === "undefined"
+                        ? timeToNextIdlePeriod
+                        : Math.min(timeout, timeToNextIdlePeriod)
+            });
+
+            return result.id || result;
+        };
+
+        clock.cancelIdleCallback = function cancelIdleCallback(timerId) {
+            return clearTimer(clock, timerId, "Timeout");
+        };
+
+        clock.setTimeout = function setTimeout(func, timeout) {
+            return addTimer(clock, {
+                func: func,
+                args: Array.prototype.slice.call(arguments, 2),
+                delay: timeout
+            });
+        };
+
+        clock.clearTimeout = function clearTimeout(timerId) {
+            return clearTimer(clock, timerId, "Timeout");
+        };
+
+        clock.nextTick = function nextTick(func) {
+            return enqueueJob(clock, {
+                func: func,
+                args: Array.prototype.slice.call(arguments, 1)
+            });
+        };
+
+        clock.queueMicrotask = function queueMicrotask(func) {
+            return clock.nextTick(func); // explicitly drop additional arguments
+        };
+
+        clock.setInterval = function setInterval(func, timeout) {
+            // eslint-disable-next-line no-param-reassign
+            timeout = parseInt(timeout, 10);
+            return addTimer(clock, {
+                func: func,
+                args: Array.prototype.slice.call(arguments, 2),
+                delay: timeout,
+                interval: timeout
+            });
+        };
+
+        clock.clearInterval = function clearInterval(timerId) {
+            return clearTimer(clock, timerId, "Interval");
+        };
+
+        if (setImmediatePresent) {
+            clock.setImmediate = function setImmediate(func) {
+                return addTimer(clock, {
+                    func: func,
+                    args: Array.prototype.slice.call(arguments, 1),
+                    immediate: true
+                });
+            };
+
+            clock.clearImmediate = function clearImmediate(timerId) {
+                return clearTimer(clock, timerId, "Immediate");
+            };
+        }
+
+        clock.countTimers = function countTimers() {
+            return (
+                Object.keys(clock.timers || {}).length +
+                (clock.jobs || []).length
+            );
+        };
+
+        clock.requestAnimationFrame = function requestAnimationFrame(func) {
+            var result = addTimer(clock, {
+                func: func,
+                delay: getTimeToNextFrame(),
+                args: [clock.now + getTimeToNextFrame()],
+                animation: true
+            });
+
+            return result.id || result;
+        };
+
+        clock.cancelAnimationFrame = function cancelAnimationFrame(timerId) {
+            return clearTimer(clock, timerId, "AnimationFrame");
+        };
+
+        clock.runMicrotasks = function runMicrotasks() {
+            runJobs(clock);
+        };
+
+        function doTick(tickValue, isAsync, resolve, reject) {
+            var msFloat =
+                typeof tickValue === "number"
+                    ? tickValue
+                    : parseTime(tickValue);
+            var ms = Math.floor(msFloat);
+            var remainder = nanoRemainder(msFloat);
+            var nanosTotal = nanos + remainder;
+            var tickTo = clock.now + ms;
+
+            if (msFloat < 0) {
+                throw new TypeError("Negative ticks are not supported");
+            }
+
+            // adjust for positive overflow
+            if (nanosTotal >= 1e6) {
+                tickTo += 1;
+                nanosTotal -= 1e6;
+            }
+
+            nanos = nanosTotal;
+            var tickFrom = clock.now;
+            var previous = clock.now;
+            var timer,
+                firstException,
+                oldNow,
+                nextPromiseTick,
+                compensationCheck,
+                postTimerCall;
+
+            clock.duringTick = true;
+
+            // perform microtasks
+            oldNow = clock.now;
+            runJobs(clock);
+            if (oldNow !== clock.now) {
+                // compensate for any setSystemTime() call during microtask callback
+                tickFrom += clock.now - oldNow;
+                tickTo += clock.now - oldNow;
+            }
+
+            function doTickInner() {
+                // perform each timer in the requested range
+                timer = firstTimerInRange(clock, tickFrom, tickTo);
+                // eslint-disable-next-line no-unmodified-loop-condition
+                while (timer && tickFrom <= tickTo) {
+                    if (clock.timers[timer.id]) {
+                        tickFrom = timer.callAt;
+                        clock.now = timer.callAt;
+                        oldNow = clock.now;
+                        try {
+                            runJobs(clock);
+                            callTimer(clock, timer);
+                        } catch (e) {
+                            firstException = firstException || e;
+                        }
+
+                        if (isAsync) {
+                            // finish up after native setImmediate callback to allow
+                            // all native es6 promises to process their callbacks after
+                            // each timer fires.
+                            originalSetTimeout(nextPromiseTick);
+                            return;
+                        }
+
+                        compensationCheck();
+                    }
+
+                    postTimerCall();
+                }
+
+                // perform process.nextTick()s again
+                oldNow = clock.now;
+                runJobs(clock);
+                if (oldNow !== clock.now) {
+                    // compensate for any setSystemTime() call during process.nextTick() callback
+                    tickFrom += clock.now - oldNow;
+                    tickTo += clock.now - oldNow;
+                }
+                clock.duringTick = false;
+
+                // corner case: during runJobs new timers were scheduled which could be in the range [clock.now, tickTo]
+                timer = firstTimerInRange(clock, tickFrom, tickTo);
+                if (timer) {
+                    try {
+                        clock.tick(tickTo - clock.now); // do it all again - for the remainder of the requested range
+                    } catch (e) {
+                        firstException = firstException || e;
+                    }
+                } else {
+                    // no timers remaining in the requested range: move the clock all the way to the end
+                    clock.now = tickTo;
+
+                    // update nanos
+                    nanos = nanosTotal;
+                }
+                if (firstException) {
+                    throw firstException;
+                }
+
+                if (isAsync) {
+                    resolve(clock.now);
+                } else {
+                    return clock.now;
+                }
+            }
+
+            nextPromiseTick =
+                isAsync &&
+                function() {
+                    try {
+                        compensationCheck();
+                        postTimerCall();
+                        doTickInner();
+                    } catch (e) {
+                        reject(e);
+                    }
+                };
+
+            compensationCheck = function() {
+                // compensate for any setSystemTime() call during timer callback
+                if (oldNow !== clock.now) {
+                    tickFrom += clock.now - oldNow;
+                    tickTo += clock.now - oldNow;
+                    previous += clock.now - oldNow;
+                }
+            };
+
+            postTimerCall = function() {
+                timer = firstTimerInRange(clock, previous, tickTo);
+                previous = tickFrom;
+            };
+
+            return doTickInner();
+        }
+
+        /**
+         * @param {tickValue} {String|Number} number of milliseconds or a human-readable value like "01:11:15"
+         */
+        clock.tick = function tick(tickValue) {
+            return doTick(tickValue, false);
+        };
+
+        if (typeof _global.Promise !== "undefined") {
+            clock.tickAsync = function tickAsync(ms) {
+                return new _global.Promise(function(resolve, reject) {
+                    originalSetTimeout(function() {
+                        try {
+                            doTick(ms, true, resolve, reject);
+                        } catch (e) {
+                            reject(e);
+                        }
+                    });
+                });
+            };
+        }
+
+        clock.next = function next() {
+            runJobs(clock);
+            var timer = firstTimer(clock);
+            if (!timer) {
+                return clock.now;
+            }
+
+            clock.duringTick = true;
+            try {
+                clock.now = timer.callAt;
+                callTimer(clock, timer);
+                runJobs(clock);
+                return clock.now;
+            } finally {
+                clock.duringTick = false;
+            }
+        };
+
+        if (typeof _global.Promise !== "undefined") {
+            clock.nextAsync = function nextAsync() {
+                return new _global.Promise(function(resolve, reject) {
+                    originalSetTimeout(function() {
+                        try {
+                            var timer = firstTimer(clock);
+                            if (!timer) {
+                                resolve(clock.now);
+                                return;
+                            }
+
+                            var err;
+                            clock.duringTick = true;
+                            clock.now = timer.callAt;
+                            try {
+                                callTimer(clock, timer);
+                            } catch (e) {
+                                err = e;
+                            }
+                            clock.duringTick = false;
+
+                            originalSetTimeout(function() {
+                                if (err) {
+                                    reject(err);
+                                } else {
+                                    resolve(clock.now);
+                                }
+                            });
+                        } catch (e) {
+                            reject(e);
+                        }
+                    });
+                });
+            };
+        }
+
+        clock.runAll = function runAll() {
+            var numTimers, i;
+            runJobs(clock);
+            for (i = 0; i < clock.loopLimit; i++) {
+                if (!clock.timers) {
+                    return clock.now;
+                }
+
+                numTimers = keys(clock.timers).length;
+                if (numTimers === 0) {
+                    return clock.now;
+                }
+
+                clock.next();
+            }
+
+            throw new Error(
+                "Aborting after running " +
+                    clock.loopLimit +
+                    " timers, assuming an infinite loop!"
+            );
+        };
+
+        clock.runToFrame = function runToFrame() {
+            return clock.tick(getTimeToNextFrame());
+        };
+
+        if (typeof _global.Promise !== "undefined") {
+            clock.runAllAsync = function runAllAsync() {
+                return new _global.Promise(function(resolve, reject) {
+                    var i = 0;
+                    function doRun() {
+                        originalSetTimeout(function() {
+                            try {
+                                var numTimers;
+                                if (i < clock.loopLimit) {
+                                    if (!clock.timers) {
+                                        resolve(clock.now);
+                                        return;
+                                    }
+
+                                    numTimers = Object.keys(clock.timers)
+                                        .length;
+                                    if (numTimers === 0) {
+                                        resolve(clock.now);
+                                        return;
+                                    }
+
+                                    clock.next();
+
+                                    i++;
+
+                                    doRun();
+                                    return;
+                                }
+
+                                reject(
+                                    new Error(
+                                        "Aborting after running " +
+                                            clock.loopLimit +
+                                            " timers, assuming an infinite loop!"
+                                    )
+                                );
+                            } catch (e) {
+                                reject(e);
+                            }
+                        });
+                    }
+                    doRun();
+                });
+            };
+        }
+
+        clock.runToLast = function runToLast() {
+            var timer = lastTimer(clock);
+            if (!timer) {
+                runJobs(clock);
+                return clock.now;
+            }
+
+            return clock.tick(timer.callAt - clock.now);
+        };
+
+        if (typeof _global.Promise !== "undefined") {
+            clock.runToLastAsync = function runToLastAsync() {
+                return new _global.Promise(function(resolve, reject) {
+                    originalSetTimeout(function() {
+                        try {
+                            var timer = lastTimer(clock);
+                            if (!timer) {
+                                resolve(clock.now);
+                            }
+
+                            resolve(clock.tickAsync(timer.callAt));
+                        } catch (e) {
+                            reject(e);
+                        }
+                    });
+                });
+            };
+        }
+
+        clock.reset = function reset() {
+            nanos = 0;
+            clock.timers = {};
+            clock.jobs = [];
+            clock.now = start;
+        };
+
+        clock.setSystemTime = function setSystemTime(systemTime) {
+            // determine time difference
+            var newNow = getEpoch(systemTime);
+            var difference = newNow - clock.now;
+            var id, timer;
+
+            adjustedSystemTime[0] = adjustedSystemTime[0] + difference;
+            adjustedSystemTime[1] = adjustedSystemTime[1] + nanos;
+            // update 'system clock'
+            clock.now = newNow;
+            nanos = 0;
+
+            // update timers and intervals to keep them stable
+            for (id in clock.timers) {
+                if (clock.timers.hasOwnProperty(id)) {
+                    timer = clock.timers[id];
+                    timer.createdAt += difference;
+                    timer.callAt += difference;
+                }
+            }
+        };
+
+        if (performancePresent) {
+            clock.performance = Object.create(null);
+
+            if (hasPerformancePrototype) {
+                var proto = _global.Performance.prototype;
+
+                Object.getOwnPropertyNames(proto).forEach(function(name) {
+                    if (name.indexOf("getEntries") === 0) {
+                        // match expected return type for getEntries functions
+                        clock.performance[name] = NOOP_ARRAY;
+                    } else {
+                        clock.performance[name] = NOOP;
+                    }
+                });
+            }
+
+            clock.performance.now = function FakeTimersNow() {
+                var hrt = hrtime();
+                var millis = hrt[0] * 1000 + hrt[1] / 1e6;
+                return millis;
+            };
+        }
+
+        if (hrtimePresent) {
+            clock.hrtime = hrtime;
+        }
+
+        return clock;
+    }
+
+    /**
+     * @param config {Object} optional config
+     * @param config.target {Object} the target to install timers in (default `window`)
+     * @param config.now {number|Date}  a number (in milliseconds) or a Date object (default epoch)
+     * @param config.toFake {string[]} names of the methods that should be faked.
+     * @param config.loopLimit {number} the maximum number of timers that will be run when calling runAll()
+     * @param config.shouldAdvanceTime {Boolean} tells FakeTimers to increment mocked time automatically (default false)
+     * @param config.advanceTimeDelta {Number} increment mocked time every <<advanceTimeDelta>> ms (default: 20ms)
+     */
+    // eslint-disable-next-line complexity
+    function install(config) {
+        if (
+            arguments.length > 1 ||
+            config instanceof Date ||
+            Array.isArray(config) ||
+            typeof config === "number"
+        ) {
+            throw new TypeError(
+                "FakeTimers.install called with " +
+                    String(config) +
+                    " install requires an object parameter"
+            );
+        }
+
+        // eslint-disable-next-line no-param-reassign
+        config = typeof config !== "undefined" ? config : {};
+        config.shouldAdvanceTime = config.shouldAdvanceTime || false;
+        config.advanceTimeDelta = config.advanceTimeDelta || 20;
+
+        var i, l;
+        var target = config.target || _global;
+        var clock = createClock(config.now, config.loopLimit);
+
+        clock.uninstall = function() {
+            return uninstall(clock, target, config);
+        };
+
+        clock.methods = config.toFake || [];
+
+        if (clock.methods.length === 0) {
+            // do not fake nextTick by default - GitHub#126
+            clock.methods = keys(timers).filter(function(key) {
+                return key !== "nextTick" && key !== "queueMicrotask";
+            });
+        }
+
+        for (i = 0, l = clock.methods.length; i < l; i++) {
+            if (clock.methods[i] === "hrtime") {
+                if (
+                    target.process &&
+                    typeof target.process.hrtime === "function"
+                ) {
+                    hijackMethod(target.process, clock.methods[i], clock);
+                }
+            } else if (clock.methods[i] === "nextTick") {
+                if (
+                    target.process &&
+                    typeof target.process.nextTick === "function"
+                ) {
+                    hijackMethod(target.process, clock.methods[i], clock);
+                }
+            } else {
+                if (
+                    clock.methods[i] === "setInterval" &&
+                    config.shouldAdvanceTime === true
+                ) {
+                    var intervalTick = doIntervalTick.bind(
+                        null,
+                        clock,
+                        config.advanceTimeDelta
+                    );
+                    var intervalId = target[clock.methods[i]](
+                        intervalTick,
+                        config.advanceTimeDelta
+                    );
+                    clock.attachedInterval = intervalId;
+                }
+                hijackMethod(target, clock.methods[i], clock);
+            }
+        }
+
+        return clock;
+    }
+
+    return {
+        timers: timers,
+        createClock: createClock,
+        install: install,
+        withGlobal: withGlobal
+    };
+}
+
+var defaultImplementation = withGlobal(globalObject);
+
+exports.timers = defaultImplementation.timers;
+exports.createClock = defaultImplementation.createClock;
+exports.install = defaultImplementation.install;
+exports.withGlobal = withGlobal;
+
+},{"@sinonjs/commons":7}]},{},[20]);
+const _timers = FakeTimers.timers;
+export { _timers as timers };
+const _createClock = FakeTimers.createClock;
+export { _createClock as createClock };
+const _install = FakeTimers.install;
+export { _install as install };
+const _withGlobal = FakeTimers.withGlobal;
+export { _withGlobal as withGlobal };
\ No newline at end of file
diff --git a/package.json b/package.json
index eab7d6c4..f0cc62d4 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
     "test-cloud": "mochify --wd --no-detect-globals --timeout=10000",
     "test-coverage": "nyc --all --reporter text --reporter html --reporter lcovonly npm run test-node",
     "test": "npm run lint && npm run test-node && npm run test-headless",
-    "bundle": "browserify --no-detect-globals -s FakeTimers -o fake-timers.js src/fake-timers-src.js",
+    "bundle": "node ./build.js",
     "prepublishOnly": "npm run bundle",
     "preversion": "./scripts/preversion.sh",
     "version": "./scripts/version.sh",
@@ -32,7 +32,8 @@
   },
   "files": [
     "src/",
-    "fake-timers.js"
+    "fake-timers.js",
+    "fake-timers-esm.js"
   ],
   "devDependencies": {
     "@sinonjs/referee-sinon": "6.0.1",
@@ -72,7 +73,7 @@
       ]
     }
   },
-  "module": "./fake-timers.js",
+  "module": "./fake-timers-esm.js",
   "main": "./src/fake-timers-src.js",
   "dependencies": {
     "@sinonjs/commons": "^1.7.0"
@@ -90,7 +91,8 @@
     "exclude": [
       "**/*-test.js",
       "coverage/**",
-      "fake-timers.js"
+      "fake-timers.js",
+      "fake-timers-esm.js"
     ]
   }
 }
diff --git a/src/fake-timers-esm.js b/src/fake-timers-esm.js
new file mode 100644
index 00000000..28124ecc
--- /dev/null
+++ b/src/fake-timers-esm.js
@@ -0,0 +1,3 @@
+"use strict";
+// eslint-disable-next-line no-undef
+FakeTimers = require("./fake-timers-src");