readme.md

Proverb

For want of a horseshoe nail, a kingdom was lost, or so the saying goes.

Given a list of inputs, generate the relevant proverb. For example, given the list ["nail", "shoe", "horse", "rider", "message", "battle", "kingdom"], you will output the full text of this proverbial rhyme:

For want of a nail the shoe was lost.
For want of a shoe the horse was lost.
For want of a horse the rider was lost.
For want of a rider the message was lost.
For want of a message the battle was lost.
For want of a battle the kingdom was lost.
And all for the want of a nail.

Note that the list of inputs may vary; your solution should be able to handle lists of arbitrary length and content. No line of the output text should be a static, unchanging string; all should vary according to the input given.

Running the tests You can run all the tests for an exercise by entering

$ gradle test in your terminal.

Source Wikipedia http://en.wikipedia.org/wiki/For_Want_of_a_Nail

Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.

Proverb.java

class Proverb {

    private String[] words;

    Proverb(String[] words) {

        this.words = words;
    }

    String recite() {

        StringBuilder proverb = new StringBuilder();

        if (words.length != 0) {

            for (int i = 0; i < (words.length - 1); i++) {
                    String lost = words[i + 1];
                    proverb.append("For want of a " + words[i] + " the " + lost + " was lost.\n");
                }

            proverb.append("And all for the want of a " + words[0] + ".");

        }
        return proverb.toString();
    }

}

ProverbTest.java

import org.junit.Ignore;
import org.junit.Test;

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

public class ProverbTest {

    @Test
    public void zeroWordsAreGiven() {
        String[] words  = new String[0];
        String proverb  = new Proverb(words).recite(),
               expected = "";

        assertThat(proverb, is(expected));
    }

    @Ignore("Remove to run test")
    @Test
    public void singlePieceOfProverb() {
        String[] words  = new String[]{"nail"};
        String proverb  = new Proverb(words).recite(),
               expected = "And all for the want of a nail.";

        assertThat(proverb, is(expected));
    }

    @Ignore("Remove to run test")
    @Test
    public void twoPiecesOfProverb() {
        String[] words  = new String[]{"nail", "shoe"};
        String proverb  = new Proverb(words).recite(),
               expected = "For want of a nail the shoe was lost.\n" +
                          "And all for the want of a nail.";

        assertThat(proverb, is(expected));
    }

    @Ignore("Remove to run test")
    @Test
    public void shortChainOfConsequences() {
        String[] words  = new String[]{"nail", "shoe", "horse"};
        String proverb  = new Proverb(words).recite(),
               expected = "For want of a nail the shoe was lost.\n" +
                          "For want of a shoe the horse was lost.\n" +
                          "And all for the want of a nail.";

        assertThat(proverb, is(expected));
    }

    @Ignore("Remove to run test")
    @Test
    public void fullProverb() {
        String[] words  = new String[]{"nail", "shoe", "horse", "rider", "message", "battle", "kingdom"};
        String proverb  = new Proverb(words).recite(),
               expected = "For want of a nail the shoe was lost.\n" +
                          "For want of a shoe the horse was lost.\n" +
                          "For want of a horse the rider was lost.\n" +
                          "For want of a rider the message was lost.\n" +
                          "For want of a message the battle was lost.\n" +
                          "For want of a battle the kingdom was lost.\n" +
                          "And all for the want of a nail.";

        assertThat(proverb, is(expected));
    }

    @Ignore("Remove to run test")
    @Test
    public void fourPiecesModernizedProverb() {
        String[] words  = new String[]{"pin", "gun", "soldier", "battle"};
        String proverb  = new Proverb(words).recite(),
               expected = "For want of a pin the gun was lost.\n" +
                          "For want of a gun the soldier was lost.\n" +
                          "For want of a soldier the battle was lost.\n" +
                          "And all for the want of a pin.";

        assertThat(proverb, is(expected));
    }

}