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improved docs
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‎README.md

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@@ -4,7 +4,7 @@ rewire
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rewire allows you to modify the behaviour of modules for better unit testing. You may
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- provide mocks for other modules
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- introduce mocks for other modules
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- leak private variables
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- override variables within the module
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- inject your own scripts
@@ -32,83 +32,74 @@ Examples
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--------
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```javascript
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var rewire = require("rewire"),
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rewiredModule;
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var rewire = require("rewire");
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// Default
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////////////////////////////////
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// rewire acts exactly like require when omitting all other params
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rewire("./myModuleA.js") === require("./myModuleA.js"); // = true
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```
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// Mocks
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////////////////////////////////
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var mockedModuleB = {},
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mockedFs = {},
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mocks = {
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"fs": mockedFs,
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"path/to/moduleB.js": mockedModuleB
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};
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### Mocks
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```javascript
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// You can introduce your own mocks for modules that are required:
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rewiredModule = rewire("./myModuleA.js", {
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"fs": {
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readFile: function (path, encoding, cb) { cb(null, "Success!"); }
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},
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"../path/to/moduleB.js": myMockForModuleB
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});
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// The rewired module will now use your mocks instead of fs
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// and moduleB.js. Just make sure that the path is exactly as
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// in myModuleA.js required.
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rewiredModule = rewire("./myModuleA.js", mocks);
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```
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// Injections
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////////////////////////////////
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var injections = {
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console: {
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log: function () { /* be quiet */ }
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},
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process: { argv: ["someArgs"] },
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__filename: "some/other/dir"
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};
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### Injections
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```javascript
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// You can inject your own mocks for internal or global objects.
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// These injections are only visible within the module.
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rewiredModule = rewire("./myModuleA.js", null, {
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console: {
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log: function () { /* be quiet */ }
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},
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process: { argv: ["some", "other", "args"] },
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__filename: "some/other/dir"
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});
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// This will inject
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// var console = {log: function () { /* be quiet */ }};
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// var process = {argv: ["someArgs"] };
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// var process = {argv: ["some", "other", "args"]};
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// var __filename = "some/other/dir";
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// at the bottom of the module.
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// This way you can override private variables within the module
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rewiredModule = rewire("./myModuleA.js", null, injections);
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// You can also pass a script to inject
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rewiredModule =
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rewire("./myModuleA.js", null, "console.log('hellooo');"); // prints "hellooo"
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// at the end of the module.
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// You can also pass a script to inject at the end
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rewiredModule = rewire("./myModuleA.js", null, "console.log('hello');");
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// This will print "hello" when the module loads
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```
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// Leaks
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////////////////////////////////
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var leaks = ["myPrivateVar1", "myPrivateVar2"];
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### Leaks
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```javascript
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// You can expose private variables for unit tests
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rewiredModule = rewire("./myModuleA.js", null, null, ["myVar1", "myVar2");
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// This will inject
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// module.exports._ = {myPrivateVar1: myPrivateVar1, myPrivateVar2: myPrivateVar2}
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// at the bottom of the module.
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rewiredModule = rewire("./myModuleA.js", null, null, leaks);
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// You now can access your private varialbes under the special __-object
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rewiredModule.__.myPrivateVar1; // returns former private variable myPrivateVar1
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rewiredModule.__.myPrivateVar2; // returns former private variable myPrivateVar2
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// module.exports.__ = {myVar1: myVar1, myVar2: myVar2}
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// at the end of the module.
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// You can access now your private variables under the special.__-object
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console.log(rewiredModule.__.myVar1);
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console.log(rewiredModule.__.myVar2);
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```
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// Cache
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////////////////////////////////
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// By disabling the module cache the rewired module will not be cached.
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// Any require()-calls will now return the original module again instead
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// of the rewired. Caching is enabled by default.
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rewire("./myModuleA.js", null, null, null, false) !==
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require("./myModuleA.js"); // = true
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### Cache
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```javascript
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// You can disable caching of the rewired module. Any require()-calls will
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// now return the original module again instead of the rewired.
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// Caching is enabled by default.
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rewire("./myModuleA.js", null, null, null, false) === require("./myModuleA.js");
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// = false
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// This removes all rewired modules from require.cache.
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// You can also delete all rewired modules from the cache by one call.
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rewire.reset();
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// IMPORTANT: You should call this before every unit test to ensure
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// a clean test environment.
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// You should call this after every unit test to ensure a clean test environment.
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```
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-----------------------------------------------------------------
@@ -122,7 +113,7 @@ rewire.reset();
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Path to the module that shall be rewired. Use it exactly like require().
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- *{Object} mocks (optional)*: <br/>
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An object with mocks.
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An object with module mocks. Keys should reflect the required path of the module.
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- *{Object|String} injections (optional)*: <br />
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If you pass an object, all keys of the object will be `var`s within the module. You can also eval a string.
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<br />
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## Please note
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### mocks
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Keys should be exactly the same like they're required in the target module.
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### Keys should be exactly the same like they're required in the target module
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So if you write `require("../../myModules/myModuleA.js")` you need to pass
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`{"../../myModules/myModuleA.js": myModuleAMock}`.
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### injections
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All scripts are injected at the end of the module. So if there is any code in your module
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that is executed during `require()`, your injected variables will be undefined at this point.
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### All scripts are injected at the end of the module
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So if there is any code in your module that is executed during `require()`, your
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injected variables will be undefined at this point.
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Imagine `rewire("./myModule.js", null, {console: null});`:
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var console = null;
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```
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### leaks
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Leaks are executed at the end of the module. If a `var` is undefined at this point you
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won't be able to access the leak (because `undefined`-values are [copied by value](http://stackoverflow.com/questions/518000/is-javascript-a-pass-by-reference-or-pass-by-value-language)).
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A good approach to this is:
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### Leaks are executed at the end of the module.
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All variables, that are [copied by value](http://stackoverflow.com/questions/518000/is-javascript-a-pass-by-reference-or-pass-by-value-language)
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will not be updated anymore.
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A good approach to solve this would be:
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```javascript
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var myLeaks = {};
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module.exports = function (someValue) {
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myLeaks.someValue = someValue;
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};
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// End of module ///////////////
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// rewire will inject here
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module.exports.__ = {myLeaks: myLeaks};
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```
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And then: ```rewire("myModuleA.js", null, null, ["myLeaks"]);```
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Because ```myLeaks``` is defined at the end of the module, you're able to access the leak object and all leaks that
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are attached to it later during runtime. Because myLeaks is not exposed under regular circumstances your
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module interface stays clean.
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are attached to it later during runtime.
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### reset
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You should call this before every unit test to ensure a clean test environment.
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### Call rewire.reset() after every unit test
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All ```require()```s will now return the original module again.
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-----------------------------------------------------------------
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<br />

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