Installation

Examples

// lib/myModule.js// With rewire you can change all these variablesvarfs=require("fs"),http=require("http"),someOtherVar="hi",myPrivateVar=1;functionreadSomethingFromFileSystem(cb){// But no scoped variablesvarpath="/somewhere/on/the/disk";console.log("Reading from file system ...");fs.readFile(path,"utf8",cb);}exports.readSomethingFromFileSystem=readSomethingFromFileSystem;

// test/myModule.test.jsvarrewire=require("rewire");// rewire acts exactly like require.varmyModule=rewire("../lib/myModule.js");// Just with one difference:// Your module will now export a special setter and getter for private variables.myModule.__set__("myPrivateVar",123);myModule.__get__("myPrivateVar");// = 123// This allows you to mock almost everything within the module e.g. the fs-module.// Just pass the variable name as first parameter and your mock as second.myModule.__set__("fs",{readFile:function(path,encoding,cb){cb(null,"Success!");}});myModule.readSomethingFromFileSystem(function(err,data){console.log(data);// = Success!});// You can set different variables with one call.myModule.__set__({fs:fsMock,http:httpMock,someOtherVar:"hello"});// You may also override globals. These changes are only within the module, so// you don't have to be concerned that other modules are influenced by your mock.myModule.__set__({console:{log:function(){/* be quiet */}},process:{argv:["testArg1","testArg2"]}});// But be careful, if you do something like this you'll change your global// console instance.myModule.__set__("console.log",function(){/* be quiet */});// There is another difference to require:// Every call of rewire() returns a new instance.rewire("./myModule.js")===rewire("./myModule.js");// = false