Classi Advent Calendar 2017 This is the article on the 13th day. I'm @kasaharu, a front-end engineer. This is the second post for the first time in 12 days.

Recently in-house ["Test Driven Development"](https://www.amazon.co.jp/%E3%83%86%E3%82%B9%E3%83%88%E9%A7%86%E5% 8B% 95% E9% 96% 8B% E7% 99% BA-Kent-Beck / dp / 4274217884) has started a reading party. (It's only once ...) I heard in advance that this book is suitable for sutra copying, so I started with the premise of copying sutras.

At that time, there was one big problem. Yes, no matter what I hide, I don't have an environment where Java runs on my Mac! However, the conflict of not wanting to include an IDE for sutra copying ...

So, today's theme is building an environment for "test-driven development" sutra copying that starts at the terminal!

Insert Java

Put in with Homebrew
Homebrew must be installed * ref. https://brew.sh/index_ja.html

$ brew tap caskroom/cask
$ brew cask install java
$ java -version
java version "9.0.1"
Java(TM) SE Runtime Environment (build 9.0.1+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.1+11, mixed mode)

Java 9 is now available without any concerns: clap:

Insert JUnit

Download the jar file from below (honestly I was wondering where to get it)
- http://repo1.maven.org/maven2/org/junit/jupiter/junit-jupiter-api/5.0.2/
To be honest, I was wondering where to get it ...
** It was the first stumbling block **
When I looked at GitHub, there was something like that and I arrived at it.
Download junit-jupiter-api-5.0.2.jar
I chose this because the first test code imported ʻorg.junit.jupiter.api. * `.
Place it anywhere
Example) $ HOME / sukina / basyo / junit-jupiter-api-5.0.2.jar
Set CLASSPATH

`bash_profile`


export CLASSPATH=$HOME/sukina/basyo/junit-jupiter-api-5.0.2.jar

All you have to do is restart the terminal

Try running the code in Chapter 1

The test code and implementation code are as follows.

`MoneyTest.java`


package money;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class MoneyTest {
  @Test
  public void testMultiplication() {
    Dollar five = new Dollar(5);
    five.times(2);
    assertEquals(10, five.amount);
  }
}

`Dollar.java`


package money;

class Dollar {
  int amount;

  Dollar(int amount) {
  }

  void times(int multiplier) {
  }
}

Run
Although a warning is issued (** 2nd stumbling **), the operation was confirmed.

$ javac Dollar.java MoneyTest.java
warning:Unknown enum constant Status.STABLE
Reason: org.apiguardian.api.API$Status class file not found
warning:Unknown enum constant Status.STABLE
2 warnings

I'm worried if the warning is still issued, so I'll go to erase it
It is said that "the class file of org.apiguardian.api.API $ Status does not exist", so prepare the following file * org/apiguardian/api/API.java

$ javac Dollar.java MoneyTest.java
(It's gone!)

(Although it runs backwards from the flow of books) When I remove the implementation of the amount field in Dollar.java, I get an error when I expected it.

$ javac Dollar.java MoneyTest.java
MoneyTest.java:11:error:Can't find symbol
    assertEquals(10, five.amount);
                         ^
symbol:Variable amount
place:Variable of type Dollar five
1 error

Summary

That's why I was ready to copy sutras without having an IDE. I'm going to have a reading party!

Tomorrow is @ spin13! stay tuned!

[JAVA] Building an environment for "test-driven development" copying sutras starting at the terminal