Week 4 exercise 3

Retrieved from SWE 437 In Class Exercise #5 JUnit. Code available in the end of the blogpost.

Question 1

Given the 4 @Test methods shown, how many times does the @Before method execute?

Just one time, it will setup the environment for the class we want to test.

Question 2

The contract for equals() states that no exceptions may be thrown. Instead, equals() is supposed to return false if passed a null argument. Write a JUnit test that verifies this property for the EH class.

@Test public void noNPE() {
assertEquals(false, eh1.equals(null));
assertEquals(false, eh2.equals(null));

Question 3

Using the given EH objects, write a test that verifies that equals() returns false if the objects are, in fact, not equal.

@Test public void equalsFalse() {
assertEquals(false, eh1.equals(eh2));
assertEquals(false, eh2.equals(eh3));

Question 4

Using the given EH objects, write a test that verifies that equals() returns true if the objects are, in fact, equal.

@Test public void equalsTrue() {
assertEquals(true, eh1.equals(eh1));
assertEquals(true, eh2.equals(eh2));
assertEquals(true, eh3.equals(eh3));

Question 5

Using the given EH objects, write a test to verify that hashCode() is consistent with equals. This test should fail if hashCode() is commented out (as shown), but pass if hashCode() is implemented.

public void hashConsistent() {
assertEquals(false, eh1.hashCode() == eh2.hashCode());
assertEquals(true, eh2.hashCode() == eh2.hashCode());
assertEquals(true, eh3.hashCode() == eh1.hashCode());

Code repository

4 of 4 test passed


Week 4 Delivery

In this week we didn’t do anything related to the project, otherwise we focused more on the part of getting more involved in testing and we did choose the technologies for testing in JavaScript: Mocha and Chai.

“Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun.”


“Chai is a BDD / TDD assertion library for nodeand the browser that can be delightfully paired with any javascript testing framework.”

Resultado de imagen para chaijs

On the other hand, we did meet up and did the team homework, research about testing and its techniques and best practices.

Chapter 3 Team Exercise

Why do testers automate tests? What are the limitations of automation?

Because it reduces the cost of testing and human error, also it makes regression testing easier because it allows a test to be run repeatedly. Excise tasks are candidates for automation.

Although this is an essential process, it has limitations:

  • Continuous adjustment to testing code
  • Cannot be used for testing UX
  • Script reliability depends on programmer
  • Requires silo elimination

How the inheritance hierarchy can affect controllability and observability?

Having a deep inheritance tree of classes could become more complex to test, because the sub classes are dependent of its father, that means, if we modify or update something in the super class, it will affect all its respective children, which means that every test affected by the modification have to be updated for the sub classes. Therefore, inheritance does not guarantee that a method tested in the context of the super class will work correctly or in the same way that in the context of the sub class or sub classes. Thus, this affects controllability because we will need to control every super class and its sub classes, and if wee have a deep inheritance tree, it will be very complicated. On the other hand, it affects observability becase we need to observe a large number of sub classes that actually are doing the same work as the super class.

Develop JUnit tests for the BoundedQueue class.

You can find the code here.

Delete the explicit throw of NullPointerException in the Min program. Verify that the JUnit test for a list with a single null element now fails.

If we delete the line

if (result == null) throw new NullPointerException ("Min.min");

We can see that the test testForSoloNullElement() fails.

6. Consider the following example class. PrimeNumbers has three methods…

(a) A test that does not reach the fault

void testComputePrimesA() {
PrimeNumbers primeNumbers = new PrimeNumbers();

assertEquals("[]", primeNumbers.toString());
// it never enters the while loop

(b) A test that reaches the fault, but does not infect

void testComputePrimesB() {
PrimeNumbers primeNumbers = new PrimeNumbers();

  assertEquals("[2, 3, 5, 7, 11, 13, 17]",

(c) A test that infects the state, but does not propagate

void testComputePrimesC() {
PrimeNumbers primeNumbers = new PrimeNumbers();

assertEquals("[2, 3, 5, 7, 11, 13, 17, 19]",
// it is affected because it doesn't include 19

(d) A test that propagates, but does not reveal

This test is not possible because the faults starts at the 19 (we’re not taking in consideration 9, because it is not prime), all of subsequent primes that ends in ‘9’ won’t be in the result value.

(e) A test that reveals the fault

void testComputePrimesE() {
PrimeNumbers primeNumbers = new PrimeNumbers();

  assertEquals("[2, 3, 5, 7, 11, 13, 17, 19]",

Exercise 7.

The computePrimes is now using the Sieve of Eratosthenes to find the primes. The first false positive result is again 9, it doesn’t print it, to reach the fault it has to compute the first 7 prime numbers. The RIPR model should be used to know if there’s a fault in our system, on the contrary, we could think that our program is running correctly, but we have so many false positives waiting to be propagated.

JUnit and Intelli-J (mac os)

What is Intelli-j? it is basically and IDE for software development, its first release was in the year 2001. It was developed by JetBrains and it’s not based on Eclipse. But i’m pretty sure you aren’t here for this but to to learn how to do a basic setup for J-Unit and Intelli-j community edition. Here is what you’ll need:

  • Mac Os X 10.5 or superior
  • 1GB of RAM as minimum.
  • JDK 1.8

The steps to follow can be found in the next video:

Quick configuration video

If link is broken go here: https://www.youtube.com/watch?v=Z8V7rnvDeB4

Detailed configuration setup video

Link: https://www.youtube.com/watch?v=6k-AA1uR5jY&feature=youtu.be

In general IntelliJ and JUnit 5 configuration is really simple. Mostly because a lot of the Maven integration is done automatically by IntelliJ. So if your goal is to learn how to set up Maven into a Java project, this is not the best method. But if you are looking for simplicity this is a very good choice.

Git repository: https://github.com/kevintroko/JUnitTest

JUnit 5 documentation:https://junit.org/junit5/docs/current/user-guide/

Test && Commit || Revert ?

About two weeks ago I started an internship in a Software company. They like to use this relatively new framework known as Agile. But it isn’t only used where I work, it seems that a lot of companies are trying to migrate to an Agile approach (or some kind of distorted version of it 🙄).

In other words, they like using the SCRUM mindset.

In other words, Ken Beck has influence my work days and probably a lot of many other people.

So after doing a lazy Google research I found out that the Agile roots (extreme programing) were mostly developed by a smart guy named Ken Beck. He did not just worked on this awesome methodology, but also contributed to Test driven developmentSmalltalk, helped popularized the CRC cards along Ward Cunningham, and made the unit testing framework JUnit. It’s incredible all the work this guy has contributed into the Software industry.

Kent Beck (right image) Was one of 17 authors of the Agile manifesto which shaped the constant changing software industry

So what about TCR?

Kent Beck proposes: TEST && Commit||Revert which basically consist in:

If my test pass then I want to commit it!

If I fell that something wrong happened in my code then I can go back to the last time it worked. Therefore, the incentive is to make small changes, all in a stable way. It’s better to have many smaller commits than a big commit with all the different changes.

This doesn’t mean you will have to write more tests. But if you are going to make 3 tests at once maybe it’s better to test one by one so the code of the 3 don’t fully disappear. As Kent Beck says:

How could you make progress if the tests always have to work? Don’t you make mistakes sometimes? What if you write a bunch of code and it just gets wiped out? Won’t you get frustrated?

Kent Beck

And yes, the mistakes will be made, we are humans and the human factor will never assure to have working code 100% of the times. But it is better to instantly wipe out all the bad code. So if you don’t want for big chumps of your work to be sent to the forgiveness then don’t make really big commits between the successful tests.

I guess most of us, university students that hadn’t finish a Testing course, program either by submitting the whole code project until the end, until it’s working as a whole. I’m not counting much the team projects because we commit occasionally, but, it’s a different reason. I think we commit to share code, not to have it safe for testing. And even deeper I guess we don’t do any formal testing.


Test Driven Development: Also created by Kent Beck (is there anything this guy can’t do?), is basically a programming practice where you have to write test first and then write the code that will pass it. Finally do a refactoring.

I don’t have a lot of experience with TDD to be honest. To be even more honest I wasn’t even sure about what it really meant. I guess my testing before this class was running a program, if something goes wrong fix it. And occasionally throw as many weird inputs to see what happens. But I want to change this. Maybe TDD is the solution, maybe not.

TDD workflow

Test Commit Revert: It’s an alternative workflow. TCR is chaotic in a sense that there will be different problems. Maybe TCR will be very weird in Github. To have a lot of tiny commits, for 12 line of code seems incorrect. But there are some solutions as squash commits. If all test passes then commit to master, if anything fails use the the revert button, Life is too short for waterfall planning.


You can read the whole Agile manifesto (all along the early 2000’s web pages experience) in here: https://agilemanifesto.org .

First Personal Post 2.0 #TC3045

Image taken from Diyfail.com

Hello my name is Kevin Oswaldo Cabrera Navarro. In the next 3 months I’ll be writing about Software testing, verification and quality. So why does Testing and quality matter?

Quick example of why quality is important sometimes

The emoji movie had a 8% score at rotten tomatoes. Photo credits to Michael Steber

I wonder if there was any quality department inside Sony pictures that didn’t realized about how bad does the idea of this movie actually is. This is the equivalent to the story about how small testing can save tons of money to a company. Probably the correlation is so arbitrary, but it is a good example of why everything should have a quality measurement (it doesn’t matter if it is a movie, a book or a software system)

No bugs in here! 🦗

One of the main goals in this blog is to prevent the usage of the word bug to refer to a fault, error or failure in a program. Maybe it is a word rich in history but in this blog I will try to follow the advices of Paul Ammann and Jeff Offutt writers of the Introduction to Software Testing book to don’t encapsulate all the different meanings into only one word.

But that’s another history for a different post. See you later

The Deadline

Mr. Tompkins, a ReSOE “Released to Seek Opportunities Elsewhere” is the protagonist of the Tom Demarco book about Project Management, if you are looking for a new way to learn about PM this book is perfect, it is a novel! so from the beginning of the story, you are transport into the world of a Gant Charts, SCRUM, changes and management risks.

If your english is not really good, there can be some hard words, but in these days there is nothing that google translate can’t resolve.

Some of my favorite Quotes from the book:

“Let me answer that question with a question. What’s the hardest job in management?”
“People,” Tompkins replied automatically. He knew exactly where he stood on this subject. “Getting the right people for the right job. That’s what makes the difference between a good manager and a drone” (DeMarco, T., 1997).

Metascore 88/100 🌕🌕🌕🌕🌗

More info in: http://www.goodreads.com/book/show/123716.The_Deadline


DeMarco, T., (1997) The Deadline, Dorset House Publishing, New York: USA.

Here I go again 🎸

🎼 It’s such a perfect day 

You may be thinking about Whitesnake song (maybe not, should you?*),  It’s the beginning of the finals week, for almost every student in the school, today is the last day of classes, that means we have to think about our performance in the semester, It works like a new year’s eve without twelve grapes or tons of fireworks, did we make all our plans true?, did you get into the new project?, did you change the world around you? did you make all the posts and stayed active on Slack in your #TI2011 class?,



We seem to enjoy to leave everything in the end, we like to do things on unhealthy marathonic ways, just like finishing a serie in one day, going to hackathons to work all day and night, do 30 post in one day, study for a final and arrive at the school without any sleep, test the slides 3 minutes before the presentation and realize it does not work, reading a complete book in one sitting, .

Hope you are not a Peter Gibbons in this life

🎼 But I didn’t have time to do it

“You know I’m sooooo busy to go to class, I have to study” “I have a lot of outside work, school is not for me, I can learn everything from an internet tutorial”


“Finals are here, I can’t do anything but study/make a project” Even the trendy Luis Fonci’s Despacito song isn’t heard as much as these phrases on finals. But of course my horse, when they meet with their teams or friends to study,  80% of the times is wasted on chatting, complaining that they have to do a lot of work, procrastinating, eat and look for memes on Facebook/Twitter/KevintrocoWordpressSite, so maybe these phrases are just a way of saying, I did have time to do it, but I spend it on videogames/partys. I kind of describe my finals week anyways.

Don’t: Be this guy After the Finals (SO)

To be honest, I enjoy to write about different things that involves the Project Management, and avoid those posts that are just resumes of the book (literally), having 2 good posts instead of 14 Mcconnell awesome mixtape, although in the end, they are necessary to fill the blog and make it to seem full of posts, we learned from the book that the amount of time you spent on planning is truly valuable in the last phases of the project.

🎼 Inevitable things of the Finals

  • Marring the “maquinita” for a week and only eat cookies and chips since you can’t go to eat something made with love or without a wrap.
  • Have eye-bags big enough to be confused with a zombie, sponsored by those large nights of studying without sleeping.
  • Make the Tec or your foreign friend house your second home, If you are not a foreign student you will not see you’re parents, which result in the next point.
  • “This ain’t a Hotel” scold by your parents when they realize you only go to sleep or eat to your house in the lately days.
  • Going crazy because you left everything at the end, and then tell yourself you will NEVER do that again.

All these things can be avoid if you have CONTROL OF YOUR TIME, procrastination is an enemy we must face.

Remember about the estimations that Mcconnell wrote in the book, following a systematic estimation procedure is effective when they are realistic, I will read these 100 books at the end of the month is not going to be completed if you have never read more than 10 pages without sleeping in the couch. In the end GOOD LUCK IN THE FINALS! show what you can do.

Captura de pantalla 2017-05-03 18.49.25

**Of course this is my opinion and it is okay if you don’t think the same, there is a lot of exceptions in students, not everybody is lazy.

Why is ITerm Open Source? Good Question


George Nachman @gnachman the creator of the ITerm project describes himself in his twitter bio as “the iTerm2 guy. I eat, sleep, and breathe terminal emulation. It is my everything.”, but what is ITerm exactly? ITerm is a GNU licensed terminal for MacOS, it supports a terminal with new features and even viewing images (for some reason).  but why is it open source? I couldn’t find a exact answer anywhere in the internet, but, I think the reason is the lack of Terminal alternatives on MacOS.

Examining under the GNU License it specifies how the software is made to share, to give you the freedom to do whatever you want, share it and change it, free to all users.

Captura de pantalla 2017-03-29 16.03.18

Looking at some responses in Quora.com, I found that the reasons why the users choose to have this terminal over the standard app, are the COLORS and mouse support,

Preliminary Planning & Football

To win the Football* league is not so different as managing a software project, at least in the planning factors, let’s talk about Chapter 7 of the book. 🥅  ⚽️💨  🏃🏻


In booth cases you have to got a Coach who manages the team, the tactics and formations before/during/after the matches, just like any software project, the project manager has to make with the given resources the best teams and put together the ones who has the best chemistry of work, the team cohesion has a very important impact on the productivity of the team. You also need resources, players (programmers), trainers, investors and more. Different  areas unite to make a good result, this means that there should be a project vision of where the project is going in order to don’t exceed the budget or fail, some soccer teams have in mind to win the league, others to avoid the relegation, having a vision helps to build a common goal that makes trust among the team towards the same objective, the team needs to be motivated and need to have a challenge or mission to achieved, sometimes the Champions League or a new revolutionary social network to compete with Facebook and will take the market share for the first months, anyways, it is important to have a real goal, you will not make a League 4 Sunday league team to win the FA CUP, or have 2 developers to make a new Call of Duty in one month, it may be uncommonly possible but not realistic, McConnell says:

A common and damaging dynamic occurs when the development team begins to realize its goals are unachievable before management does. If management continues to insist that the goals are achievable after the team has figured out that they are not, team motivation and morale can sink fast.

Executive Sponsorship 

Executive sponsorship is the support given to the person or group who has the final authority over the project wide decisions (ask Barça or any of those multimillionaire teams or tech companies like Sony), The Coach may be in charge of the players to be fit and win matches, but his boss is the one who is in charge of the team, just like a PM is responsible for committing to a project, but the release to its users is in other authority chair, they are also the ones who give the money to buy those fancy players that will win the league for them.


Risk management

A risk is a possibility of loss or injury, Software development involves risk, football involves risk, changing the battery of your computer involves risk, everything has a chance of risk or loss, sometimes there are star players that get injuries or that don’t fulfill the expectations, this is where the manager will decide what to do, in a football team or in a software project, if you find a difficult persons, works as quickly as possible, because the negativity and the effects in the team will be lowered, sometimes teams just lose finals because the aggressively plays that leads to red cards.


Because the project manager as the coach are the ones who give the face of success or failure in a project, projects needs to reduce risk, they are faced into the risk management, there are three approaches that McConnell describe in the book of Software Project Survival Guide.

  1. Project plan must describe a risk.
  2. The budget for the project must include funds for the risk solution.
  3. She risks are assessed, their impacts must be incorporated into project plans.

If a player is injured, there must be a substitute, if a programmer doesn’t give the task on time, there must be a new approach to make him work as desired, sometimes football fans act like the risk officer, who appoint that some players are not in the best shape, although sometimes just like McConnell says, the are just “designated pessimist” that does not like the tactics, the risk officer must have the management point of view and respect too.


Maybe the coach is not playing on the field, but he is the one that is in charge of the tactics to succeed, just like the Project Manager

Successful projects begin planning early, they define the project vision, identify an executive sponsor, set targets for the project scope, manage risks and map out the strategies, which is useful and important.

in the end ProjectManagement == Coach

*✌🏻Soccer✌🏻 for North Americans