Tomi Daily

Test-driven development

2006-04-17T12:01:00.000-07:00

Simplily speaking, Test-driven development is to write the test plan before writing the code, and implement toe code follow the test plan.

quote from http://en.wikipedia.org/wiki/Test_driven_development#Requirements

Test-Driven Development Cycle

1. Write the test
It begins with writing a test. In order to write a test, the developer must understand the specification and the requirements clearly. This is accomplished through use cases and user stories. The design document covers all the test scenarios and exception conditions.

2. Write the code
The next step is to make the test pass by writing the code. This step forces the programmer to take the perspective of a client by seeing the code through its interfaces. This is the design driven part of test-driven development. As part of test calibration, your code should fail the test meaningfully the first time around.

3. Run the automated tests
The next step is to run the automated test cases and observe if they pass or fail. If they pass, the programmer can be more confident that the code meets the test cases as written. If there are failures, the code did not meet the test cases..

4. Refactor
The final step is the refactoring step and any code clean-up necessary will occur here. The test cases are then re-run and observed.

5. Repeat
The cycle will then repeat itself and start with either adding additional functionality or fixing any errors.

Benefits
Despite the initial requirements, test-driven development can provide great value to building software better and faster. It offers more than just simple validation of correctness, but can also drive the design of a program. By focusing on the test cases first, one must imagine how the functionality will be used by clients (in this case, the test cases). Therefore, the programmer is only concerned with the interface and not the implementation. This benefit is complementary to Design by Contract as approaches it through test cases rather than mathematical assertions.
The power test-driven development offers is the ability to take small steps when required. It allows a programmer to focus on the task at hand and often the first goal is to make the test pass. Exceptional cases and error handling are not considered initially. These extraneous circumstances are implemented after the main functionality has been achieved. Another advantage is that test-driven development, when used properly, ensures that all written code is covered by a test. This can give the programmer a greater level of trust in the code.

Why do software project fails?

2006-04-17T11:41:00.001-07:00

Why do software project fails?
I think there are several cause:
1) Changing/losting of delvelopment teamates
Extra time may be needed to employ new developer, or time needed for other teamate to follow up the case.

2)Dependence to "new" techology
In planning time, team assume that any new techology will be finish at ??? time, and planed to use this technology , however, the "new" technology cannot finish ontime, delay/fail to finish the project may occur.

3)poor testing plan
testing is one of the most important part of the software development, so if the testing plan is poorly planed, the final product may contains lots of unexpected bugs.

4)poor estimation on budget
Extra employment, extra cost of new techology, extra cost of hardware price may cause the out budget case occurs.

Why do software project fails?

2006-04-17T11:41:00.000-07:00

My feeling about the design pattern

2006-04-10T08:01:00.000-07:00

The one I know best: Adapter pattern
Adapter design pattern is used to enable objects/classes with different interfaces to communicate with each other.
It is mainly used to provide a new interface to existing legacy components.

The one I know worst: Proxy pattern
Actually I'm not really know why a proxy is needed to add in the design.

What make coding perfect?

2006-03-17T07:13:00.000-08:00

I think no one will argue that, "A good programmer should write a good program"
but, what is a good program?

Simply specking, a good coding should:
Easy to read, Easy to understand and Easy to modify.

There are thousand of method to solve a problem,
however, not all the solution are high readability.
I will perfer a simple and easy to understand coding,
than a clever but hard to read coding.

Morever, I like some coding that contain detail comment.
This can make me more easy to follow the program.

Finally, I think a good coding need a well orginized.
They should seperate any related method into one class,
then it is very helpful for other programer to modifly the program(EG. testing, add/remove function)

Real meaning behind some software engineering's slogan

2006-02-25T08:37:00.000-08:00

"Will You Pair With Me?"
I think this slogan fits the "Pair Programming" in SE.
From http://www.methodsandtools.com/archive/archive.php?id=10
They breifly expain that the problems may appear in the pair programming
It got grestest benifit if the pairs got similar ability,
but if miss pairing occurs ,
the developement of the program may be affected
So I think "Will You Pair With Me?" can rephrase to "Am I have the ability to pair with you"
or "Do you have the ability to pair with me"

"Don’t Get Stressed, Write A Test"
Testing is one of the most important part in software developement
However, this step is the "nightmare" of software engineer,
During planning the test for programs,
software engineer may feel stress on thinking the test
eg. "Can all the test case prevent all the bugs?","Is there any case we have missed?" etc
It is very heavy for the testing team.

Differences between IEEE Certified Software Development Professional (CSDP) Program and our learning in OUHK Software Engineering

2006-02-25T08:03:00.000-08:00

On the topics list of the CSDP,
the topics covered can mainly divided into 11 main parts:

I. Professionalism and Engineering Economics
II. Software Requirements
III. Software Design
IV. Software Construction
V. Software Testing
VI. Software Maintenance
VII. Software Engineering Management
VIII. Software Configuration Management
IX. Software Engineering Process
X. Software Engineering Tools and Methods
XI. Software Quality

And after my "quick skimming" from the textbook,
I think the areas that textbook haven't contain are:
I. Professionalism and Engineering Economics
XI. Software Quality

Actually these two areas are mainly about some experience of software engineer...
so I think it is resionable that these topics are missing in the textbook.

PS. however, I remember that Pro. Steven has taught these topic in his lectures/tutorials...^^"

辛酸的迪士尼客服,可怕的2月1日

2006-02-01T10:57:00.000-08:00

迪士尼給大家的印象怎樣呢?如童話般的漂亮,美好嗎?

剛在電視上看到有關今天(2月1日)香港迪士尼主題公園(下文簡稱樂園)所發生的事:
樂園入場人數上限為3萬人,但預訂以及即人購票的人仕大約有3萬5千人
因此樂園在早上11時左右停止遊人入場大批未能入場的遊客則在門外聚集
電視片段中,
有人試圖爬過圍欄,
有小孩哭著要進場玩,
有成人就說車站/樂園沒有說明情況...

看到此新聞後,我就開始預電我的女友(她在樂園的guest relationship 客戶服務部工作)
本應在一小時多前下班的她卻遲遲未有接聽
直到半小時前左右,才收到她的通電以及知道樂園內的真實情況

她用了2個字去形容遊客們: 暴徒
電視上的只是冰山一角
遊客們不只爬過圍欄,
而且有人推倒"水馬"(膠做的半身高圍欄,倒水入內以加強重量)
有人爬上燈柱(大約....3-4米高吧)
甚至有人把鐵欄上的"防盜用的矛頭狀設計"(恕小弟不知道它的學名...)拆下來投向工作人員...
甚至有想有進一步的暴力行為

身為客戶服務的女友唯有盡量忍耐及對遊客說明情況
可惜消減不到遊人們的怒氣
她更看到有遊人申手入服務中心的櫃位內搶走鍵盤並破壞
主任/高層卻在袖手旁觀
更加罵小客服們做得不夠好,
事件在警方協助,以及3時左右樂園重開,而輕微的緩和...
一件小插曲是今天"又"有一名客服因為受不住壓力而請辭...好像已經第7-8個了...

我這個"半局外人"只可以說
遊客們一心想到樂園玩一天來到門前卻不能入內的心情...
我都非常明白/同情
但是...可以用和平點的方法表示你們的不滿嗎?

MY feedback of using the UML Tools

2005-10-31T15:26:00.000-08:00

As we are request to try using the UML tools, here are some feedback of my testing.
A)Visal Paradigm
Easy to use:5 (5 points as max)
Size of the program:~155MB
Comment:
Visal Paradigm is very easy to use and userfriendly.
The item icons are placed on the left hand side, which is very easy and very clear for user to use.
Suitable for lastest comer to UML.

B)Poseidon
easy to use: 4
Size of the program: ~40.7MB
Poseidon is the secont program I tried to use.
Comment:
I think that the icon / items are not so many to use, but it is acceptable.
Not so many UML Diagram to use, may be it is because I've try the Trial version...

C)Eclipse
easy to use:2
Size of the program: ~30MB
Comment:
Eclipse is the most difficult program I've test.
The item are poor placed, Difficult to find and use.
I think this program is suitable for the programmer to use,
it can generate java code automatially.

My own idea to software engineering

2005-09-28T22:19:00.000-07:00

Sorry for so late to update this blog... I dont know why I cant use / watch this blog at my home T^T...

Q1) What do you think about the basic software engineering skills?
I remember that Steven (my tutor of Software engineering) has tell us that main idea of S.E. is "to finish the system in limited time and budget". So, I think the most important skill of software engineer is "know how to manage time and money efficiently", on the other words, they should know very well how to finish work.
For why managing time is so important, different from the other techology (e.g. making a car, build a building), the software techology may change every day, and also for the client's requirement.So it is very important to finish the job as soon as possible.
Moreover, since software engineer are work for different customer(s), and the system may use on different area, so the software engineer must get a basic knowledge on every area, or have the ability to learn the knowledge in short time.

(modified at 1 Oct.,2005)

First day to using BLOG...

2005-09-21T23:20:00.000-07:00

It's the first time to using BLOG,
let me say "HI" for all of the visiter~~^^

I'm Tomi Lam from Hongkong, studying in Open University Year3, in IT.

For why I create this BLOG.....
actually it is because my tutor Steven needs our class to own one...=.=
however... I'll try and enjoy to use it ^^"

Today is my third day for me to sudying in Open U, I think tutor ar quite nice, and also for the classmate. Hope that I can have a happy study life here~^^

Tomi Lam 22/9/2005
ICQ#128466502