Add sinon package for mocking

node_modules/sinon/lib/sinon/fake.js

@@ -0,0 +1,106 @@
+"use strict";
+
+var arrayProto = require("@sinonjs/commons").prototypes.array;
+var createProxy = require("./proxy");
+var nextTick = require("./util/core/next-tick");
+
+var slice = arrayProto.slice;
+
+function getError(value) {
+    return value instanceof Error ? value : new Error(value);
+}
+
+var uuid = 0;
+function wrapFunc(f) {
+    var proxy;
+    var fakeInstance = function() {
+        var firstArg, lastArg;
+
+        if (arguments.length > 0) {
+            firstArg = arguments[0];
+            lastArg = arguments[arguments.length - 1];
+        }
+
+        var callback = lastArg && typeof lastArg === "function" ? lastArg : undefined;
+
+        proxy.firstArg = firstArg;
+        proxy.lastArg = lastArg;
+        proxy.callback = callback;
+
+        return f && f.apply(this, arguments);
+    };
+    proxy = createProxy(fakeInstance, f || fakeInstance);
+
+    proxy.displayName = "fake";
+    proxy.id = "fake#" + uuid++;
+
+    return proxy;
+}
+
+function fake(f) {
+    if (arguments.length > 0 && typeof f !== "function") {
+        throw new TypeError("Expected f argument to be a Function");
+    }
+
+    return wrapFunc(f);
+}
+
+fake.returns = function returns(value) {
+    function f() {
+        return value;
+    }
+
+    return wrapFunc(f);
+};
+
+fake.throws = function throws(value) {
+    function f() {
+        throw getError(value);
+    }
+
+    return wrapFunc(f);
+};
+
+fake.resolves = function resolves(value) {
+    function f() {
+        return Promise.resolve(value);
+    }
+
+    return wrapFunc(f);
+};
+
+fake.rejects = function rejects(value) {
+    function f() {
+        return Promise.reject(getError(value));
+    }
+
+    return wrapFunc(f);
+};
+
+function yieldInternal(async, values) {
+    function f() {
+        var callback = arguments[arguments.length - 1];
+        if (typeof callback !== "function") {
+            throw new TypeError("Expected last argument to be a function");
+        }
+        if (async) {
+            nextTick(function() {
+                callback.apply(null, values);
+            });
+        } else {
+            callback.apply(null, values);
+        }
+    }
+
+    return wrapFunc(f);
+}
+
+fake.yields = function yields() {
+    return yieldInternal(false, slice(arguments));
+};
+
+fake.yieldsAsync = function yieldsAsync() {
+    return yieldInternal(true, slice(arguments));
+};
+
+module.exports = fake;