It totally feels like cheating, but since no one else is answering the question, here goes:

- Proxyquire takes over `require` and lets you inject fakes anywhere in the dependency chain.  For `require`s you don&#39;t take over and for methods you don&#39;t define for `require`s you do take over, it&#39;ll fall back to the original. This can be disabled with `noCallThru`. Thus it still loads the original, just replaces things with the things you define.  Unlike Rewire and SandboxedModule, you can&#39;t define global variables for your `require` overloads.

- Rewire takes over `require` and injects `__get__` and `__set__` properties into each module.  If you know the private variable name, you can replace it.  Think dependency injection.

- SandboxedModule is nearly identical to Proxyquire except it runs the entire process in a new V8 vm.  (There is a per-test performance cost to this approach.)  It also has a nasty bug in v 1.0 that makes it fail when something you didn&#39;t replace references a native module it doesn&#39;t support.  See https://github.com/robrich/sandboxed-module-graceful-fs.

- Sinon doesn&#39;t take over `require` like the other 3.  Rather, it&#39;s a more traditional mocking framework.  Replace specified methods with fakes, or create a mock that tracks when it was called.

Trying to create a MongoDB data source with [icCube][1]. The idea is to return the size of an array as a new field. Something like :

    $project:
    { 
     &quot;people&quot;: 1, 
     &quot;Count myFieldArray&quot; : {$size : &quot;$myFieldArray&quot; }
    }

But I&#39;m getting for some records the following error :

    The argument to $size must be an Array, but was of type: EOO

Is there a way that size is 0 if the field is empty or not an array (getting rid of the error) ?


  [1]: http://www.iccube.com

MongoDB - The argument to $size must be an Array, but was of type: EOO / missing

I&#39;m kind of new to batch scripting.
As a newbie I find both both of them useful while scripting
What are the key differences between xcopy and robocopy?



Difference between xcopy and robocopy

When mocking Node dependencies, I&#39;ve happened upon the following libraries:

- [Proxyquire](https://github.com/thlorenz/proxyquire)
- [Rewire](https://github.com/jhnns/rewire)
- [SandboxedModule](https://github.com/felixge/node-sandboxed-module)
- [Sinon](http://sinonjs.org/)

They all seem to do more-or-less the same thing: allow you to mock `require()` calls (with the exception of Sinon which mocks pretty much everything).  They all seem to require some pretty elaborate setup, noting the exact syntax of the string passed to `require` -- not great during refactoring.

What are the pros and cons of each library?  When would I choose one over the other?  What are example use-cases where each library excels?  What are other products in this space that are better?

Proxyquire, rewire, SandboxedModule, and Sinon: pros &amp; cons

When mocking Node dependencies, I've happened upon the following libraries:
<ul>
<li><a href="https://github.com/thlorenz/proxyquire" target="_blank" rel="noopener noreferrer">Proxyquire</a></li>
<li><a href="https://github.com/jhnns/rewire" target="_blank" rel="noopener noreferrer">Rewire</a></li>
<li><a href="https://github.com/felixge/node-sandboxed-module" target="_blank" rel="noopener noreferrer">SandboxedModule</a></li>
<li><a href="http://sinonjs.org/" target="_blank" rel="noopener noreferrer">Sinon</a></li>
</ul>
They all seem to do more-or-less the same thing: allow you to mock <code>require()</code> calls (with the exception of Sinon which mocks pretty much everything). They all seem to require some pretty elaborate setup, noting the exact syntax of the string passed to <code>require</code> -- not great during refactoring.
What are the pros and cons of each library? When would I choose one over the other? What are example use-cases where each library excels? What are other products in this space that are better?

I&#39;ve spent quite a while scouring the internet looking for the best way to properly document callbacks with jsdoc, but unfortunately, I haven&#39;t found a great one yet.

Here&#39;s my question:

I&#39;m writing a Node.js library for developers. This library provides multiple classes, functions, and methods that developers will be working with.

In order to make my code clear and understandable, as well as to (hopefully) auto-generate some API documentation in the future, I&#39;ve started using [jsdoc][1] in my code to self-document what&#39;s happening.

Let&#39;s say I define a function like the following:

    function addStuff(x, y, callback) {
      callback(x+y);
    });

Using jsdoc, I&#39;m currently documenting this function as follows:

    /**
      * Add two numbers together, then pass the results to a callback function.
      *
      * @function addStuff
      * @param {int} x - An integer.
      * @param {int} y - An integer.
      * @param {function} callback - A callback to run whose signature is (sum), where
      *  sum is an integer.
      */
    function addStuff(x, y, callback) {
      callback(x+y);
    });

I feel like the above solution is kinda hack-ish, since there&#39;s no way for me to specify in absolute terms what the callback function should accept.

Ideally, I&#39;d like to do something like:

    /**
      * Add two numbers together, then pass the results to a callback function.
      *
      * @function addStuff
      * @param {int} x - An integer.
      * @param {int} y - An integer.
      * @param {callback} callback - A callback to run.
      * @param {int} callback.sum - An integer.
      */
    function addStuff(x, y, callback) {
      callback(x+y);
    });

The above seems like it&#39;d allow me to more simply convey what my callback needs to accept.  Does that make sense?

I guess my question is simple: what&#39;s the best way to clearly document my callback functions with jsdoc?

Thank you for your time.

  [1]: http://usejsdoc.org/

What&#39;s the proper way to document callbacks with jsdoc?

Does anyone know what **events** are built-in in **Socket.io**?  
For example: `connection`, `disconnect`, `join` etc.

List of Socket.io Events

My node installation is at:

`/usr/local/bin/node`

and I&#39;ve added the shebang:

`#!/usr/local/bin/node`

to the top of the file and given my node app file the permissions 755, but when I try to run:

`&gt; ./my-app`

I get the old:

`-bash: ./my-app: No such file or directory`

What am I doing wrong?

node and shebang : help executing via command line

Following the upgrade to Express 4, and the removal of app.router, I&#39;m struggling to get middleware to execute after routes execute.

e.g. the following code correctly responds with &quot;hello&quot;, but never calls the configured middleware

    var express = require( &quot;express&quot; )();
    
    express.get( &quot;/&quot;, function( req, res ) {
    
    	res.send( &quot;hello&quot; );
    
    } );
    express.use( function( req, res, next ) {
    
    	console.log( &quot;world&quot; );
        next();
    
    } );
    
    express.listen( 8888 );

CLARIFICATION:

the following code shows &quot;before&quot; on the console, but not &quot;after&quot;:

    var express = require( &quot;express&quot; )();
    
    express.use( function( req, res, next ) {
    
    	console.log( &quot;before&quot; );
    	next();
    
    } );
    express.get( &quot;/&quot;, function( req, res ) {
    
    	res.send( &quot;hello&quot; );
    
    } );
    express.use( function( req, res, next ) {
    
    	console.log( &quot;after&quot; );
    	next();
    
    } );
    
    express.listen( 8888 );

Node Express 4 middleware after routes

After [yesterday&#39;s news of Shocker][1], it seems like apps inside a Docker container should not be run as root.  I tried to update my `Dockerfile` to create an app user however changing permissions on app files (while still root) doesn&#39;t seem to work.  I&#39;m guessing this is because some LXC permission is not being granted to the root user maybe?

Here&#39;s my Dockerfile:

    # Node.js app Docker file

    FROM dockerfile/nodejs
    MAINTAINER Thom Nichols &quot;thom@thomnichols.org&quot;

    RUN useradd -ms /bin/bash node

    ADD . /data
    # This next line doesn&#39;t seem to have any effect:
    RUN chown -R node /data 

    ENV HOME /home/node
    USER node

    RUN cd /data &amp;&amp; npm install

    EXPOSE 8888

    WORKDIR /data

    CMD [&quot;npm&quot;, &quot;start&quot;]


Pretty straightforward, but when I `ls -l` everything is still owned by root:

    [ node@ed7ae33e76e1:/data {docker-nonroot-user} ]$ ls -l /data
    total 64K
    -rw-r--r--  1 root root  383 Jun 18 20:32 Dockerfile
    -rw-r--r--  1 root root  862 Jun 18 16:23 Gruntfile.js
    -rw-r--r--  1 root root 1.2K Jun 18 15:48 README.md
    drwxr-xr-x  4 root root 4.0K May 30 14:24 assets/
    -rw-r--r--  1 root root  416 Jun  3 14:22 bower.json
    -rw-r--r--  1 root root  930 May 30 01:50 config.js
    drwxr-xr-x  4 root root 4.0K Jun 18 16:08 lib/
    drwxr-xr-x 42 root root 4.0K Jun 18 16:04 node_modules/
    -rw-r--r--  1 root root 2.0K Jun 18 16:04 package.json
    -rw-r--r--  1 root root  118 May 30 18:35 server.js
    drwxr-xr-x  3 root root 4.0K May 30 02:17 static/
    drwxr-xr-x  3 root root 4.0K Jun 18 20:13 test/
    drwxr-xr-x  3 root root 4.0K Jun  3 17:38 views/


---

[My updated dockerfile works great][2] thanks to @creak&#39;s clarification of how volumes work.  Once the initial files are `chown`ed, `npm install` is run as the non-root user.  And thanks to a `postinstall` hook, npm runs `bower install &amp;&amp; grunt assets` which takes care of the remaining install steps and avoids any need to `npm install -g` any node cli tools like bower, grunt or coffeescript.

  [1]: https://news.ycombinator.com/item?id=7909622
  [2]: https://gist.github.com/thom-nic/5e561e800cbc0f71555c

Running app inside Docker as non-root user

I don&#39;t understand the difference between Mock, Stub, and Spy in Spock testing and the tutorials I have been looking at online don&#39;t explain them in detail. 



Difference between Mock / Stub / Spy in Spock test framework

Joda Time has a nice [DateTimeUtils.setCurrentMillisFixed()][1] to mock time.  

It&#39;s very practical in tests.  

Is there an equivalent in [Java 8&#39;s java.time API][2]?


  [1]: https://www.joda.org/joda-time/apidocs/org/joda/time/DateTimeUtils.html#setCurrentMillisFixed-long-
  [2]: http://docs.oracle.com/javase/8/docs/api/java/time/package-summary.html

Mocking time in Java 8&#39;s java.time API

I am using pythons mock.patch and would like to change the return value for each call.
Here is the caveat:
the function being patched has no inputs, so I can not change the return value based on the input.

Here is my code for reference.

    def get_boolean_response():
        response = io.prompt(&#39;y/n&#39;).lower()
        while response not in (&#39;y&#39;, &#39;n&#39;, &#39;yes&#39;, &#39;no&#39;):
            io.echo(&#39;Not a valid input. Try again&#39;])
            response = io.prompt(&#39;y/n&#39;).lower()
    
        return response in (&#39;y&#39;, &#39;yes&#39;)


My Test code:

    @mock.patch(&#39;io&#39;)
    def test_get_boolean_response(self, mock_io):
        #setup
        mock_io.prompt.return_value = [&#39;x&#39;,&#39;y&#39;]
        result = operations.get_boolean_response()
    
        #test
        self.assertTrue(result)
        self.assertEqual(mock_io.prompt.call_count, 2)


`io.prompt` is just a platform independent (python 2 and 3) version of &quot;input&quot;. So ultimately I am trying to mock out the users input. I have tried using a list for the return value, but that doesn&#39;t seam to work.

You can see that if the return value is something invalid, I will just get an infinite loop here. So I need a way to eventually change the return value, so that my test actually finishes.

(another possible way to answer this question could be to explain how I could mimic user input in a unit-test)

---

Not a dup of [this question][1] mainly because I do not have the ability to vary the inputs.

One of the comments of the Answer on [this question][2] is along the same lines, but no answer/comment has been provided.


  [1]: https://stackoverflow.com/questions/7665682/python-mock-object-with-method-called-multiple-times
  [2]: https://stackoverflow.com/questions/21927057/mock-patch-os-path-exists-with-multiple-return-values

Python mock multiple return values

I have encountered something mysterious, when using patch decorator from mock package integrated with pytest fixture.

I have two modules:

        -----test folder
              -------func.py
              -------test_test.py

in func.py:

        def a():
	        return 1

        def b():
	        return a()     

in test_test.py:

        import pytest
        from func import a,b
        from mock import patch,Mock

        @pytest.fixture(scope=&quot;module&quot;)
        def brands():
	        return 1


        mock_b=Mock()

        @patch(&#39;test_test.b&#39;,mock_b)
        def test_compute_scores(brands):                 
	         a()

It seems that patch decorate is not compatible with pytest fixture. Does anyone have a insight on that? Thanks

@Patch decorator is not compatible with pytest fixture

My usual test case looks like 

    it(&quot;should send get request&quot;, inject(function(someServices) {
         //some test
    }));

And Jasmine 2.0 async test should look like

    it(&quot;should send get request&quot;, function(done) {
         someAsync.then(function(){
             done();
         });
    });

How can I use both done and inject in one test?


Jasmine 2.0 async done() and angular-mocks inject() in same test it()

I want to stub `process.env.FOO` with `bar`.

    var sinon = require(&#39;sinon&#39;);
    var stub = sinon.stub(process.env, &#39;FOO&#39;, &#39;bar&#39;);

I&#39;m confused.
I read document, but still I don&#39;t understand yet.[sinonjs docs](http://sinonjs.org/docs/)

sinonjs is one example, not sinonjs is okay.


How to stub process.env in node.js?

I have a function I am stubbing that gets called with multiple arguments. I want to check **just the first argument**. The rest are callback function, so I want to leave them alone. Thus, I might have the following 2 calls, using ajax as an example:

    method.get = sinon.stub();
    method.get(25,function(){/* success callback */},function(){/* error callback */});         
    method.get(10,function(){/* success callback */},function(){/* error callback */});

I cannot use `method.get.calls...` because then it doesn&#39;t differentiate between the first one `get(25)` and the second `get(10)`. But if I use `method.get.withArgs(25).calls...` then it does not match either, because `withArgs()` matches **all** arguments, which this does not (and never could, with callbacks like that).

How do I get sinon stubs to check and set responses based on just the 1st arg?

Can sinon stub withArgs match some but not all arguments

I want to verify that various date fields were updated properly but I don&#39;t want to mess around with predicting when `new Date()` was called. How do I stub out the Date constructor?

    import sinon = require(&#39;sinon&#39;);
    import should = require(&#39;should&#39;);

    describe(&#39;tests&#39;, () =&gt; {
      var sandbox;
      var now = new Date();

      beforeEach(() =&gt; {
        sandbox = sinon.sandbox.create();
      });

      afterEach(() =&gt; {
        sandbox.restore();
      });

      var now = new Date();

      it(&#39;sets create_date&#39;, done =&gt; {
        sandbox.stub(Date).returns(now); // does not work

        Widget.create((err, widget) =&gt; {
          should.not.exist(err);
          should.exist(widget);
          widget.create_date.should.eql(now);

          done();
        });
      });
    });

In case it is relevant, these tests are running in a node app and we use TypeScript.


How do I stub new Date() using sinon?

I am using Mocha, Chai, Karma, Sinon, Webpack for Unit tests.

I followed this link to configure my testing environment for React-Redux Code.

[How to implement testing + code coverage on React with Karma, Babel, and Webpack][1]

I can successfully test my action and reducers javascript code, but when it comes to testing my components it always throw some error.



    import React from &#39;react&#39;;
    import TestUtils from &#39;react/lib/ReactTestUtils&#39;; //I like using the Test Utils, but you can just use the DOM API instead.
    import chai from &#39;chai&#39;;
    // import sinon from &#39;sinon&#39;;
    import spies from &#39;chai-spies&#39;;
    
    chai.use(spies);
    
    let should = chai.should()
      , expect = chai.expect;
    
    import { PhoneVerification } from &#39;../PhoneVerification&#39;;
    
    let fakeStore = {
    	  &#39;isFetching&#39;: false,
    	  &#39;usernameSettings&#39;: {
    	    &#39;errors&#39;: {},
    	    &#39;username&#39;: &#39;sahil&#39;,
    	    &#39;isEditable&#39;: false
    	  },
    	  &#39;emailSettings&#39;: {
    	    &#39;email&#39;: &#39;test@test.com&#39;,
    	    &#39;isEmailVerified&#39;: false,
    	    &#39;isEditable&#39;: false
    	  },
    	  &#39;passwordSettings&#39;: {
    	    &#39;errors&#39;: {},
    	    &#39;password&#39;: &#39;showsomestarz&#39;,
    	    &#39;isEditable&#39;: false
    	  },
    	  &#39;phoneSettings&#39;: {
    	    &#39;isEditable&#39;: false,
    	    &#39;errors&#39;: {},
    	    &#39;otp&#39;: null,
    	    &#39;isOTPSent&#39;: false,
    	    &#39;isOTPReSent&#39;: false,
    	    &#39;isShowMissedCallNumber&#39;: false,
    	    &#39;isShowMissedCallVerificationLink&#39;: false,
    	    &#39;missedCallNumber&#39;: null,
    	    &#39;timeLeftToVerify&#39;: null,
    	    &#39;_verifiedNumber&#39;: null,
    	    &#39;timers&#39;: [],
    	    &#39;phone&#39;: &#39;&#39;,
    	    &#39;isPhoneVerified&#39;: false
    	  }
    }
    
    function setup () {
    	console.log(PhoneVerification);
    	// PhoneVerification.componentDidMount = chai.spy();
    	let output = TestUtils.renderIntoDocument(&lt;PhoneVerification {...fakeStore}/&gt;);
    	return {
    		output
    	}
    }
    
    describe(&#39;PhoneVerificationComponent&#39;, () =&gt; {
    	it(&#39;should render properly&#39;, (done) =&gt; {
    		const { output } = setup();
    		expect(PhoneVerification.prototype.componentDidMount).to.have.been.called;
    		done();
    	})
    });

This following error comes up with above code.

    FAILED TESTS:
      PhoneVerificationComponent
        ✖ should render properly
          Chrome 48.0.2564 (Mac OS X 10.11.3)
        Error: Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined.

Tried switching from sinon spies to chai-spies.

How should I unit test my React-Redux Connected Components(Smart Components)? 


  [1]: https://medium.com/@scbarrus/how-to-get-test-coverage-on-react-with-karma-babel-and-webpack-c9273d805063#.7kcckz73r

How to Unit Test React-Redux Connected Components?

Though there is a same question here but I could not find answer to my problem so here goes my question: 

I am testing my node js app using mocha and chai. I am using sinion to wrap my function. 

    describe(&#39;App Functions&#39;, function(){

      let mockObj = sinon.stub(testApp, &#39;getObj&#39;, (dbUrl) =&gt; {
         //some stuff
      });
      it(&#39;get results&#39;,function(done) {
         testApp.someFun
      });
    }

    describe(&#39;App Errors&#39;, function(){

      let mockObj = sinon.stub(testApp, &#39;getObj&#39;, (dbUrl) =&gt; {
         //some stuff
      });
      it(&#39;throws errors&#39;,function(done) {
         testApp.someFun
      });
    }

When I try to run this test it gives me error 

    Attempted to wrap getObj which is already wrapped

I also tried putting 

    beforeEach(function () {
      sandbox = sinon.sandbox.create();
    });

    afterEach(function () {
      sandbox.restore();
    });

in each describe, but still giving me same error. 





Content Type	Original Author	Original Content on Stackoverflow
Question	robrich	View Question on Stackoverflow
Solution 1 - node.js	robrich	View Answer on Stackoverflow

Proxyquire, rewire, SandboxedModule, and Sinon: pros & cons

node.js Problem Overview

node.js Solutions

Solution 1 - node.js

Difference between xcopy and robocopy

MongoDB - The argument to $size must be an Array, but was of type: EOO / missing

Attributions