TDD stands for Test-Driven Development, or Test-Driven Design. It is the practice of writing a unit test before writing code to satisfy it, in what is known as the Red-Green-Refactor cycle.

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Writing a gem supporting compiled languages with Rake. How to test?

I want to create a gem that extends the functionality of Rake, creating commands for compiling .NET code.* Basically, I want to be able to write a Rakefile like this: desc "Build main executable" ...
9
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4answers
821 views

How to do Test Driven Development

I have just 2+ years of experience in application development. In those two years my approach towards development was as following Analyze requirements Identity Core component/Objects, Required ...
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5answers
2k views

How do you convince management to “invest” in unit tests?

How did you convince your manager to let you unit test? By "use", I mean being allowed to develop, check-in to source control and maintain the unit tests over time, etc. Typical management ...
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344 views

How to write unit tests for a piece of code that has a data context?

I am new to unit testing and using Microsoft's unit testing library for following piece of code. When I execute the code normally it executes fine, however when I run unit test written for this code I ...
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3answers
1k views

How can I unit test audio?

I have inherited a small project and want to extend it and stabilize it at the same time by writing Unit Tests for all the new code I am adding. The first class, TypedAudioCreator, creates audio files ...
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2answers
178 views

TDD and Writing Tests for File Processing

These questions are very similar: TDD for batch processing: How to do it? and TDD: how to test file outputs? but I'm still left wondering some things The app processes files/pdfs. It takes them from ...
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1answer
113 views

What TDD/BDD tests should be writen to test an ORM

So I'm writing an ORM for NodeJS and using Mocha + Chai to test it. What I want to know is, what tests I should write to it, insertion tests should also have a querying test so I can check if the ...
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2answers
113 views

Refactoring: reducing duplication without creating flags

I don't know how to refactor a piece of code that differs from other in the number of conditions checked on an if clause. Let me show you a real world example I'm facing right now. The only ...
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1answer
90 views

Starting a big application with unit testing [closed]

I am learning test driven develeopment and read some books about TDD. I learned rules of unit testing. How can I write unit test, how can I select test method names, Act, Assert, Action and like this. ...
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2answers
301 views

TDD with repository pattern

In my new project, I decided to try with TDD. And in very beginning I encountered a problem. First thing that I want to do in my application is to give ability to read data from data source. For this ...
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2answers
176 views

Test Driven Development when the specifications change

These days, it's fairly common for me to be tasked to make a change that actually breaks the prior spec. I know that one of the major ideas behind TDD is to have a suite that verifies all your changes ...
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6answers
2k views

How do you keep your unit tests working when refactoring?

In another question, it was revealed that one of the pains with TDD is keeping the testing suite in sync with the codebase during and after refactoring. Now, I'm a big fan of refactoring. I'm not ...
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1answer
181 views

Unit test approaches other than test-first and test-last? And what about variants of them? [closed]

I'm wondering if there are other approaches, old or new, to writing unit tests, and how viable they are, other than the traditional and tdd unit testing approaches. I know there is behavior-driven ...
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3answers
104 views

Generating test data for a search application

I have a general question about testing search applications, and what I'm looking for is pointers to resources on the topic that I can go and research on my own. I've tried semi-informed, ...
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5answers
1k views

How to unit test a function that is refactored to strategy pattern?

If I have a function in my code that goes like: class Employee{ public string calculateTax(string name, int salary) { switch (name) { case "Chris": ...
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2answers
146 views

Should you mock key-value stores/aggregators

I've always been taught that your tests should run in isolation, and other than a db for ActiveRecord etc., your tests should not rely on any external software/services. e.g. I always mock my other ...
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2answers
66 views

Unit testing the variables passed to the view from the controller

Let's say I want to test a controller that gets some value from a service and then pass some of all of those values to the view. Do you test that the view gets the result that the controller took ...
11
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4answers
743 views

Is it OK to introduce methods that are used only during unit tests?

Recently I was TDDing a factory method. The method was to create either a plain object, or an object wrapped in a decorator. The decorated object could be of one of several types all extending ...
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2answers
246 views

Should a class validate argument using external method/service with unit testing?

I have a class that runs as a service and returns html code of a website when supplied with a URL. The code: public interface IHtmlDownloader { IWebProxy Proxy { get; set; } string UserAgent ...
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6answers
553 views

I'm confused about which is the correct way to work with TDD

I'm trying to grasp what's the idea behind TDD and how a team is supposed to work with it. I have the following test case with NUnit + Moq (just writing by memory, it is not assured the example ...
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3answers
197 views

What's the idea behind mocking data access in unit tests [duplicate]

I understand that you're not actually supposed to hit the database or disk when doing unit tests... Why is that? Also, taking something like Moq, what is it actually supposed to mock and where? For ...
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1answer
295 views

2 questions about TDD

I'm just starting to get to grips with TDD, and I have 2 quick questions; I'm assuming that if I were writing software for a software company, that TDD would work alongside the software design? i.e ...
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20answers
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Why does TDD work?

Test-driven development (TDD) is big these days. I often see it recommended as a solution for a wide range of problems here in Programmers SE and other venues. I wonder why it works. From an ...
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1answer
116 views

More appropriate to validate a dependency filter parameter by mock+stub or by expression compile?

My lead is enforcing TDD on our project. He says he's following Uncle Bob (Robert Martin) and SOLID principles. One of the rules he's reinforcing is what I call "the single cog rule"--there should be ...
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2answers
305 views

Whose responsibility is it to create the interface and/or acceptance testing? Developer or QA?

I am a backend developer and always create tests for my applications. Recently I study and apply the interface tests (using selenium), but I doubted whether I who should create these tests, developer ...
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1k views

In TDD should I have to write Test first or Interface first?

I am learning TDD using c#, as far as I know test should drive the development, that is first write a failing test after write the bare minimum code to pass the test then do refactoring. But it is ...
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2answers
84 views

Should I put the name of the method I'm testing in the Unit Test method's name/assert message?

Given that a method's name might change in time, is it a good idea to specify the name of the method whose return value I am asserting as a part of the Unit Test method's name? What about the message ...
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1answer
97 views

Do you spend your effort to reuse obsolete unit tests or rewrite them entirely? [closed]

I have this javascript project which has a unit test suite(about 200unit tests) that covers about 11.31% of the code that it was testing. The project has evolved greatly but the unit tests where never ...
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6answers
1k views

Do you really have to do BDD/TDD in a test first manner?

Even though I haven't been in a TDD or BDD project, or I have been in some that say they are doing TDD but are pretty far from it, these are things that I think about and really try to read as much as ...
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3answers
429 views

Orthogonality of unit tests vs. concision of unit tests

I'm writing unit tests for a steering system for a video game. The system has several behaviours (avoid this area because of reason A, avoid this area because of reason B, each adding a bit of context ...
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5answers
583 views

If we have TDD and BDD why do we need QA for? [duplicate]

If we have TDD and BDD why do we need QA for? Isn't the job of the developer to write bugs or failing tests? If this is true how a QA fit in? Thanks.
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5answers
327 views

TDD: how to test file outputs?

I'm really new to TDD, so I guess this question is pretty basic. We're building a website, and part of the functionality is generating some files (binary files: Excel, PDF, whatever). How should I ...
42
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9answers
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What are the disadvantages of test-first programming?

It's all the rage nowadays. "Everyone" recommends it. That in and of itself makes me suspicious. What are some disadvantages you have found when doing test-first (test-driven) development? I'm ...
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16answers
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When is unit testing inappropriate or unnecessary? [duplicate]

It seems to be generally assumed (on Stack Overflow at least) that there should always be unit tests, and they should be kept up to date. But I suspect the programmers making these assertions ...
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2answers
136 views

In the BDD paradigm why should the “ubiquitous language” be merely semi-formal and not completely formal?

Here's the relevant quote: A common risk with software development includes communication breakdowns between Developers and Business Stakeholders. BDD uses the specification of desired behavior as ...
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2answers
289 views

Test Driven Development for Complex Games

I'm coding a game in my spare time, but I am mostly still a beginner when it comes to programming. I'm sorry if this question is off topic or if it ends up not being helpful to anyone else, but ...
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2answers
239 views

BDD/TDD - exhaustively testing details which are low-level, but still behaviour

We're looking to concentrate more on testing behaviour (as opposed to every class/method individually) in all our automated tests, as espoused by various high-profile online discussions recently. I ...
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0answers
65 views

Mixing newable and injectable in a Callable

I recently read http://misko.hevery.com/2008/09/30/to-new-or-not-to-new/ which discussed newable vs injectable objects. What would you do if you needed to make a Callable that talks to some service ...
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4answers
342 views

Test-Driven Design is not Unit Testing [closed]

Ran across this statement by Martin Fowler circa 2002: Unit testing in XP is often unlike classical unit testing, because in XP you're usually not testing each unit in isolation. You're testing ...
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8answers
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What are good unit tests to cover the use case of rolling a die?

I'm trying to get to grips with unit testing. Say we have a die which can has a default number of sides equal to 6 (but can be 4, 5 sided etc.): import random class Die(): def __init__(self, ...
10
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1answer
466 views

Testing strategy for games

I've inherited a web-based educational game. Over the past year I've worked towards stabilizing the code and adding new features. Most of the logic is in the front-end, so back-end unit tests, while ...
154
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16answers
14k views

Why does automated testing keep failing in my company?

We have tried to introduce developer automated testing several times at my company. Our QA team uses Selenium to automate UI tests, but I always wanted to introduce unit tests and integration tests. ...
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3answers
120 views

Is it anti-pattern to mix unit test and web test? [duplicate]

It is a language agnostic question, e.g. I have a unit test like # Unit test User user = User.create('john'); assertEquals("User name is john", "john", user.getName()); # Web test start from here ...
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2answers
59 views

Isolated Unit Tests and Fine Grained Failures

One of the reasons often given to write unit tests which mock out all dependencies and are thus completely isolated is to ensure that when a bug exists, only the unit tests for that bug will fail. ...
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2answers
553 views

In which cases Robolectric is a relevant solution? [closed]

As you may now, Robolectric is a framework that provides stubs for Android objects, in order to make tests runnable outside the Dalvik environment. My concern is that, by doing this, one can fake a ...
2
votes
1answer
140 views

How is the correct way of writing TDD for a void API?

Ok so my scenario is this: I have a third party component that offers an API for communicating with an external system. The method calls for commanding the external system to do stuff, all return ...
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2answers
160 views

Is it ok to write “extra” unit tests?

My understanding of how TDD should work is that you write a failing test for the next bit of functionality you want to add to a function or object, code until the test passes and then write the next ...
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3answers
259 views

Drawback of using static method [duplicate]

For methods that never access instance variable or static variable and they act just like a function (name-spaced) and they are deterministic base on only the input arguments , I want to ask, are ...
5
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1answer
164 views

Testing that an attribute does not exist cannot fail when writing tests before code

I have been taught to follow the Red->Greeen->Refactor pattern when doing TDD. There have been situations where this pattern have not been applicable though. For instance, a test to make sure that a ...
51
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7answers
5k views

Writing Tests for Existing Code

Suppose one had a relatively large program (say 900k SLOC in C#), all commented/documented thoroughly, well organized and working well. The entire code base was written by a single senior developer ...