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Fix issue #1218: Arrange, Act, Assert pattern (#1221)

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* add AAA pattern

* reformat comment

* use Testing in readme tags in stead of Unit Test
This commit is contained in:
Zhang WH
2020-05-18 02:44:53 +08:00
committed by GitHub
parent 845da1fa16
commit 1c26bd7416
7 changed files with 301 additions and 0 deletions
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57
arrange-act-assert/src/main/java/com/iluwatar/arrangeactassert/Cash.java Normal file
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/*
* The MIT License
* Copyright © 2014-2019 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.arrangeactassert;
/**
* Arrange/Act/Assert (AAA) is a unit test pattern. In this simple example, we have a ({@link Cash})
* object for plus, minus and counting amount.
*/
public class Cash {
private int amount;
Cash(int amount) {
this.amount = amount;
}
//plus
void plus(int addend) {
amount += addend;
}
//minus
boolean minus(int subtrahend) {
if (amount >= subtrahend) {
amount -= subtrahend;
return true;
} else {
return false;
}
}
//count
int count() {
return amount;
}
}

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arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAAATest.java Normal file
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/*
* The MIT License
* Copyright © 2014-2019 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.arrangeactassert;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import org.junit.Test;
/**
* Arrange/Act/Assert (AAA) is a pattern for organizing unit tests. It is a way to structure your
* tests so they're easier to read, maintain and enhance.
*
* <p>It breaks tests down into three clear and distinct steps:
* <p>1. Arrange: Perform the setup and initialization required for the test.
* <p>2. Act: Take action(s) required for the test.
* <p>3. Assert: Verify the outcome(s) of the test.
*
* <p>This pattern has several significant benefits. It creates a clear separation between a test's
* setup, operations, and results. This structure makes the code easier to read and understand. If
* you place the steps in order and format your code to separate them, you can scan a test and
* quickly comprehend what it does.
*
* <p>It also enforces a certain degree of discipline when you write your tests. You have to think
* clearly about the three steps your test will perform. But it makes tests more natural to write at
* the same time since you already have an outline.
*
* <p>In ({@link CashAAATest}) we have four test methods. Each of them has only one reason to
* change and one reason to fail. In a large and complicated code base, tests that honor the single
* responsibility principle are much easier to troubleshoot.
*/
public class CashAAATest {
@Test
public void testPlus() {
//Arrange
var cash = new Cash(3);
//Act
cash.plus(4);
//Assert
assertEquals(cash.count(), 7);
}
@Test
public void testMinus() {
//Arrange
var cash = new Cash(8);
//Act
var result = cash.minus(5);
//Assert
assertTrue(result);
assertEquals(cash.count(), 3);
}
@Test
public void testInsufficientMinus() {
//Arrange
var cash = new Cash(1);
//Act
var result = cash.minus(6);
//Assert
assertFalse(result);
assertEquals(cash.count(), 1);
}
@Test
public void testUpdate() {
//Arrange
var cash = new Cash(5);
//Act
cash.plus(6);
var result = cash.minus(3);
//Assert
assertTrue(result);
assertEquals(cash.count(), 8);
}
}

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arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAntiAAATest.java Normal file
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/*
* The MIT License
* Copyright © 2014-2019 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.arrangeactassert;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import org.junit.Test;
/**
* ({@link CashAAATest}) is an anti-example of AAA pattern. This test is functionally correct, but
* with the addition of new feature, it needs refactoring. There are an awful lot of steps in that
* test method, but it verifies the class' important behavior in just eleven lines. It violates the
* single responsibility principle. If this test method failed after a small code change, it might
* take some digging to discover why.
*/
public class CashAntiAAATest {
@Test
public void testCash() {
//initialize
var cash = new Cash(3);
//test plus
cash.plus(4);
assertEquals(cash.count(), 7);
//test minus
cash = new Cash(8);
assertTrue(cash.minus(5));
assertEquals(cash.count(), 3);
assertFalse(cash.minus(6));
assertEquals(cash.count(), 3);
//test update
cash.plus(5);
assertTrue(cash.minus(5));
assertEquals(cash.count(), 3);
}
}