Beta 7 with some repo names changed.

Client/node_modules/class-is/index.js

@@ -0,0 +1,66 @@
+'use strict';
+
+function withIs(Class, { className, symbolName }) {
+    const symbol = Symbol.for(symbolName);
+
+    const ClassIsWrapper = {
+        // The code below assigns the class wrapper to an object to trick
+        // JavaScript engines to show the name of the extended class when
+        // logging an instances.
+        // We are assigning an anonymous class (class wrapper) to the object
+        // with key `className` to keep the correct name.
+        // If this is not supported it falls back to logging `ClassIsWrapper`.
+        [className]: class extends Class {
+            constructor(...args) {
+                super(...args);
+                Object.defineProperty(this, symbol, { value: true });
+            }
+
+            get [Symbol.toStringTag]() {
+                return className;
+            }
+        },
+    }[className];
+
+    ClassIsWrapper[`is${className}`] = (obj) => !!(obj && obj[symbol]);
+
+    return ClassIsWrapper;
+}
+
+function withIsProto(Class, { className, symbolName, withoutNew }) {
+    const symbol = Symbol.for(symbolName);
+
+    /* eslint-disable object-shorthand */
+    const ClassIsWrapper = {
+        [className]: function (...args) {
+            if (withoutNew && !(this instanceof ClassIsWrapper)) {
+                return new ClassIsWrapper(...args);
+            }
+
+            const _this = Class.call(this, ...args) || this;
+
+            if (_this && !_this[symbol]) {
+                Object.defineProperty(_this, symbol, { value: true });
+            }
+
+            return _this;
+        },
+    }[className];
+    /* eslint-enable object-shorthand */
+
+    ClassIsWrapper.prototype = Object.create(Class.prototype);
+    ClassIsWrapper.prototype.constructor = ClassIsWrapper;
+
+    Object.defineProperty(ClassIsWrapper.prototype, Symbol.toStringTag, {
+        get() {
+            return className;
+        },
+    });
+
+    ClassIsWrapper[`is${className}`] = (obj) => !!(obj && obj[symbol]);
+
+    return ClassIsWrapper;
+}
+
+module.exports = withIs;
+module.exports.proto = withIsProto;