當比較大字符串時，JUnit assertEquals的更詳細的輸出

Question

我剛完成家庭作業任務，並通過了大學的自動評估。我想爲它做單元測試，現在我知道這是正確的，但練習使用JUnit。

我學會了如何override and read standard output和simulate standard input。我寫我自己的方法：

public static void simulateIn(final String str) { 
    // Simulated STDIN 
    final ByteArrayInputStream in = new ByteArrayInputStream(str.getBytes()); 
    System.setIn(in); 
} 

我用它如下：

@Test 
public void TestOnePlusOne() throws Exception { 
    simulateIn("1 1 1 1"); 
    // Homework assignment executes here 
    new Lab01().homework(); 
    // Expected input. I didn't translate it, but it's just a simple calculator 
    assertEquals("Vyber operaci (1-soucet, 2-rozdil, 3-soucin, 4-podil):\n" + 
       "Zadej scitanec: \n" + 
       "Zadej scitanec: \n" + 
       "Zadej pocet desetinnych mist: \n" + 
       "1.0 + 1.0 = 2.0\n", outContent.toString()); 
} 

我離開了預期的輸出翻譯，它真的什麼都無所謂它現在說。重要的是，測試失敗，我得到的只是這個：

------------------------------------------------------- 
T E S T S 
------------------------------------------------------- 
Running test.TestCalculator 
Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.097 sec <<< FAILURE! 

Results : 

Failed tests: TestOnePlusOne(test.TestCalculator): expected:<...desetinnych mist: 

Tests run: 1, Failures: 1, Errors: 0, Skipped: 0 

這是非常無益的。由於我知道這個分配是正確的，所以這在單元測試中是錯誤的。我可以得到assertEquals失敗的字符串的完整區別嗎？

Answer 1

試圖再現相同的故障，我給這與一試 -

@Test 
public void log() { 
    Assert.assertEquals("Vyber operaci (1-soucet, 2-rozdil, 3-soucin, 4-podil):\n" + 
      "Zadej scitanec: \n" + 
      "Zadej scitanec: \n" + 
      "Zadej pocet desetinnych mist: \n" + 
      "1.0 + 1.0 = 2.0\n", ""); // empty string to make sure this fails 
} 

從含有上述測試類的模塊上的根目錄中的命令行執行命令mvn clean install。這導致以下日誌 - 在日誌中

Running TestOne 
true 
Tests run: 2, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.356 sec <<< FAILURE! - in TestOne 
log on log(TestOne)(TestOne) Time elapsed: 0.007 sec <<< FAILURE! 
org.junit.ComparisonFailure: 
expected:<[Vyber operaci (1-soucet, 2-rozdil, 3-soucin, 4-podil): 
Zadej scitanec: 
Zadej scitanec: 
Zadej pocet desetinnych mist: 
1.0 + 1.0 = 2.0 
]> but was:<[]> 
     at TestOne.log(TestOne.java:17) 

注意幾個細節 -

1. 運行TestOne - 測試類的名稱
2. 日誌（TestOne） - 名的方法
3. org.junit.ComparisonFailure
4. 類型的故障預期和實際.. 但

只是爲了確保一致性，我用Apache Maven 3.3.9和maven-surefire-plugin:2.19.1

<dependencies> 
    ... 
</dependencies> 
<build> 
    <plugins> 
     <plugin> 
      <groupId>org.apache.maven.plugins</groupId> 
      <artifactId>maven-surefire-plugin</artifactId> 
      <version>2.19.1</version> 
     </plugin> 
    </plugins> 
</build>