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Q:
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Consider the following String
array definitions:
private static final String[] ADJECTIVES = {
"red", "green", "yellow", "gray", "solid", // Index 4
"fierce", "friendly", "cowardly", "convenient", "foreign", // Index 9
"national", "tall", "short", "metallic", "golden", // Index 14
"silver", "sweet", "nationwide", "competitive", "stable", // Index 19
"municipal", "famous" }; // Index 21
private static final String[] THINGS = {
"elephant", "bowl", "brick", "spoon", "bunny", // Index 4
"watermelon", "car", "cat", "cup", "desk", // Index 9
"tangerine", "duck", "bottle", "road" , "fork", // Index 14
"physicist", "griffon", "hat", "key", "knife", // Index 19
"lawyer", "llama", "manual", "meat", "monitor", // Index 24
"mouse", "dog", "paper", "pear", "pen", // Index 28
"pencil", "phone", "glass", "planet", "potato", // Index 34
"engineer", "salad", "shoe", "slipper", "soup", // Index 39
"building", "star", "steak", "table", "terminal", // Index 44
"treehouse", "truck", "cake", "window" }; // Index 48
private static final String[] VERBS = {
"plans cease fire against", "expected to sell","expected to buy","speaks to","leases", // Index 4
"signs partnership with", "advances towards","meets with", "seen with","sells", // Index 9
"is authorized to sell", "signs truce with","converts into", "buys", "rents", // Index 14
"allegedly speaks to", "collapses on", "invests on", "warns", "threatens",// Index 19
"reported to have met with","now manages", "starts war with","accuses", "becomes" , // Index 24
"works together with" }; // Index 25
Following the build principle “The {adjective}
{thing} {verb} a {thing}.” we may randomly generate
nonsense phrases like e.g.:
The red meat now manages a bunny.
The metallic duck works together with a duck.
The competitive bottle signs truce with a treehouse.
The nationwide potato buys a monitor. Implement an appropriate phrase generator obeying the
following guidelines:
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Use a random number generator. Test your implementation
by a simple main() method.
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Your solution should still work when extending the
mentioned arrays of verbs, things and adjectives.
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Your solution should be testable. But having a random
number generator in place effectively defies
testability.
Define an appropriate interface which allows for
cheating by replacing a random generator with a
(deterministic) sequence generator. The latter will then be
used for unit testing allowing for predictable results.
Thus you effectively mock a random generator by a
predictable sequence generator:
@Test
public void testApp() {
final NonsenseGenerator nonsenseGenerator = new NonsenseGenerator(
new PredictableSequenceGenerator(new int[]{
//adjective thing verb thing
3, 7, 19, 26, // First sentence fixed index values
6, 20, 7, 15 // Second sentence fixed index values
}));
Assert.assertEquals("The gray cat threatens a dog.",
nonsenseGenerator.generateRandomSentence());
Assert.assertEquals("The friendly lawyer meets with a physicist.",
nonsenseGenerator.generateRandomSentence());
}
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No. 183
