gaspersic/java-design-patterns
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

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

Browse Source 
* 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
Download Patch File Download Diff File Expand all files Collapse all files

30
arrange-act-assert/README.md Normal file
View File

@ -0,0 +1,30 @@
---
layout: pattern
title: Arrange/Act/Assert
folder: arrange-act-assert
permalink: /patterns/arrange-act-assert/
categories: Idiom
tags:
- Testing
---
## Also known as
Given/When/Then
## Intent
The Arrange/Act/Assert (AAA) is a pattern for organizing unit tests.
It breaks tests down into three clear and distinct steps:
1. Arrange: Perform the setup and initialization required for the test.
2. Act: Take action(s) required for the test.
3. Assert: Verify the outcome(s) of the test.
## Applicability
Use Arrange/Act/Assert pattern when
* you need to structure your unit tests so they're easier to read, maintain, and enhance.
## Credits
* [Arrange, Act, Assert: What is AAA Testing?](https://blog.ncrunch.net/post/arrange-act-assert-aaa-testing.aspx)
* [Bill Wake: 3A – Arrange, Act, Assert](https://xp123.com/articles/3a-arrange-act-assert/)
* [Martin Fowler: GivenWhenThen](https://martinfowler.com/bliki/GivenWhenThen.html)

11
arrange-act-assert/etc/arrange-act-assert.urm.puml Normal file
View File

@ -0,0 +1,11 @@
@startuml
package com.iluwatar.arrangeactassert {
class Cash {
- amount : int
~ Cash(amount : int)
~ count() : int
~ minus(subtrahend : int) : boolean
~ plus(addend : int)
}
}
@enduml

44
arrange-act-assert/pom.xml Normal file
View File

@ -0,0 +1,44 @@
<?xml version="1.0" encoding="UTF-8"?>
<!--
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.
-->
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>java-design-patterns</artifactId>
<groupId>com.iluwatar</groupId>
<version>1.23.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>arrange-act-assert</artifactId>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</project>

57
arrange-act-assert/src/main/java/com/iluwatar/arrangeactassert/Cash.java Normal file
View File

@ -0,0 +1,57 @@
/*
* 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;
}
}

99
arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAAATest.java Normal file
View File

@ -0,0 +1,99 @@
/*
* 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);
}
}

59
arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAntiAAATest.java Normal file
View File

@ -0,0 +1,59 @@
/*
* 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);
}
}

1
pom.xml
View File

@ -184,6 +184,7 @@
<module>combinator</module>
<module>update-method</module>
<module>leader-followers</module>
<module>arrange-act-assert</module>
</modules>
<repositories>