Unit Test String with AssertJ

Table of Contents

提供了一組豐富的斷言和真正有用的錯誤訊息，提高了測試程式碼的可讀性，通常與 JUnit 測試一起使用， Unit Test Java AssertJ String 流式斷言，本篇增加了範例，並透過單元測試來驗證產出結果。

檔案目錄

./
   +- src
       +- test
       |   +- org
       |       +- ruoxue
       |           +- spring_boot_168
       |               +- test
       |                   +- assertj
       |                       +- string
       |                           +- UnitTestStringWithAssertJTest.java

單元測試

Java AssertJ String Unit Test 斷言字串的主要目的是取得字串以進行斷言。

is

驗證是否符合條件，若不成立，則會拋出 AssertionError 。

	@Test
	public void is() {
		String value = "AssertJ 155";
		System.out.println(value);
		Condition<String> length = new Condition<String>(s -> s.length() > 10, "length");
		System.out.println(value);
		assertThat(value).is(length);

		value = "AssertJ";
		System.out.println(value);
		length = new Condition<String>(s -> s.length() > 6, "length");
		System.out.println(value);
		assertThat(value).is(length);

	}

AssertJ 155
AssertJ

isNot

Java AssertJ String Unit Test 驗證是否不符合條件，若不成立，則會拋出 AssertionError 。

	@Test
	public void isNot() {
		String value = "AssertJ 155";
		System.out.println(value);
		Condition<String> length = new Condition<String>(s -> s.length() > 11, "length");
		assertThat(value).isNot(length);

		value = "AssertJ";
		System.out.println(value);
		length = new Condition<String>(s -> s.length() > 7, "length");
		assertThat(value).isNot(length);
	}

AssertJ 155
AssertJ

isIn

Java AssertJ String Unit Test 驗證是否包含於陣列中，若不成立，則會拋出 AssertionError 。

	@Test
	public void isIn() {
		String value = "AssertJ";
		System.out.println(value);
		assertThat(value).isIn("AssertJ", "155");

		value = "155";
		System.out.println(value);
		assertThat(value).isIn("AssertJ", "155");
	}

AssertJ 
155

isNotIn

Java AssertJ String Unit Test 驗證是否不包含於陣列中，若不成立，則會拋出 AssertionError 。

	@Test
	public void isNotIn() {
		String value = "AssertJ";
		System.out.println(value);
		assertThat(value).isNotIn("JUnit", "151");

		value = "155";
		System.out.println(value);
		assertThat(value).isNotIn("JUnit", "151");
	}

AssertJ 
155

isInstanceOf

Java AssertJ String Unit Test 驗證是否為指定類別實例，若不成立，則會拋出 AssertionError 。

	@Test
	public void isInstanceOf() {
		String value = "AssertJ 155";
		System.out.println(value);
		assertThat(value).isInstanceOf(String.class);

		value = new String("AssertJ 155");
		System.out.println(value);
		assertThat(value).isInstanceOf(String.class);

	}

AssertJ 155
AssertJ 155

isNotInstanceOf

Java AssertJ String Unit Test 驗證是否不為指定類別實例，若不成立，則會拋出 AssertionError 。

	@Test
	public void isNotInstanceOf() {
		String value = "AssertJ 155";
		System.out.println(value);
		assertThat(value).isNotInstanceOf(String[].class);

		value = new String("AssertJ 155");
		System.out.println(value);
		assertThat(value).isNotInstanceOf(String[].class);
	}

AssertJ 155
AssertJ 155

startsWith

Java Unit Test AssertJ String 驗證是否為第一個字串，若不成立，則會拋出 AssertionError 。

	@Test
	public void startsWith() {
		String value = "AssertJ 155";
		System.out.println(value);
		assertThat(value).startsWith("AssertJ");

		value = "155 AssertJ";
		System.out.println(value);
		assertThat(value).startsWith("155");
	}

AssertJ 155
155 AssertJ

endsWith

Java Unit Test AssertJ String 驗證是否為最後個字串，若不成立，則會拋出 AssertionError 。

	@Test
	public void endsWith() {
		String value = "AssertJ 155";
		System.out.println(value);
		assertThat(value).endsWith("155");

		value = "155 AssertJ";
		System.out.println(value);
		assertThat(value).endsWith("AssertJ");
	}

AssertJ 155
155 AssertJ

UnitTestStringWithAssertJTest.java

Java Unit Test AssertJ String 新增單元測試，驗證是否符合預期。

package org.ruoxue.spring_boot_168.test.assertj.string;

import static org.assertj.core.api.Assertions.assertThat;

import org.assertj.core.api.Condition;
import org.junit.jupiter.api.Test;

public class UnitTestStringWithAssertJTest {

	@Test
	public void is() {
		String value = "AssertJ 155";
		System.out.println(value);
		Condition<String> length = new Condition<String>(s -> s.length() > 10, "length");
		System.out.println(value);
		assertThat(value).is(length);

		value = "AssertJ";
		System.out.println(value);
		length = new Condition<String>(s -> s.length() > 6, "length");
		System.out.println(value);
		assertThat(value).is(length);

	}

	@Test
	public void isNot() {
		String value = "AssertJ 155";
		System.out.println(value);
		Condition<String> length = new Condition<String>(s -> s.length() > 11, "length");
		assertThat(value).isNot(length);

		value = "AssertJ";
		System.out.println(value);
		length = new Condition<String>(s -> s.length() > 7, "length");
		assertThat(value).isNot(length);
	}

	@Test
	public void isIn() {
		String value = "AssertJ";
		System.out.println(value);
		assertThat(value).isIn("AssertJ", "155");

		value = "155";
		System.out.println(value);
		assertThat(value).isIn("AssertJ", "155");
	}

	@Test
	public void isNotIn() {
		String value = "AssertJ";
		System.out.println(value);
		assertThat(value).isNotIn("JUnit", "151");

		value = "155";
		System.out.println(value);
		assertThat(value).isNotIn("JUnit", "151");
	}

	@Test
	public void isInstanceOf() {
		String value = "AssertJ 155";
		System.out.println(value);
		assertThat(value).isInstanceOf(String.class);

		value = new String("AssertJ 155");
		System.out.println(value);
		assertThat(value).isInstanceOf(String.class);

	}

	@Test
	public void isNotInstanceOf() {
		String value = "AssertJ 155";
		System.out.println(value);
		assertThat(value).isNotInstanceOf(String[].class);

		value = new String("AssertJ 155");
		System.out.println(value);
		assertThat(value).isNotInstanceOf(String[].class);
	}

	@Test
	public void startsWith() {
		String value = "AssertJ 155";
		System.out.println(value);
		assertThat(value).startsWith("AssertJ");

		value = "155 AssertJ";
		System.out.println(value);
		assertThat(value).startsWith("155");
	}

	@Test
	public void endsWith() {
		String value = "AssertJ 155";
		System.out.println(value);
		assertThat(value).endsWith("155");

		value = "155 AssertJ";
		System.out.println(value);
		assertThat(value).endsWith("AssertJ");
	}
}

心得分享

AssertJ String Java Unit Test 斷言的基本方法是 assertThat 方法，提高了測試程式碼的可讀性，並且被設計為在主流 IDE 中易於使用，讓開發者將繁瑣的測試驗證過程，變為更簡單，善用 Java Unit Test AssertJ String 將有助於驗證效率的提升。