Asserting Predicates with AssertJ - AssertJ 155

Asserting Predicates with AssertJ – AssertJ 155

Asserting Predicates with AssertJ

介紹 matches 、 satisfies 驗證是否符合條件,類似的流暢或鍊式寫法,語法跟自然語言相近,對於編寫測試時力求容易閱讀及維護這之上提供了相當大的改進, Assert Predicates in Java 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
       |                       +- predicate
       |                           +- AssertingPredicatesTest.java   

單元測試

Assertions Predicates in Java 斷言 Predicate 的主要目的是取得 Predicate 以進行斷言。

matches

Assertions Predicates in Java 驗證是否符合條件,若不成立,則會拋出 AssertionError 。

	@Test
	public void matches() {
		Predicate<String> lengthGreaterThan = s -> s.length() > 3;
		System.out.println(lengthGreaterThan);
		assertThat(lengthGreaterThan).matches(p -> p.test("AssertJ"));

		Predicate<Integer> greaterThan = i -> i > 10;
		System.out.println(greaterThan);
		assertThat(greaterThan).matches(p -> p.test(155));
	}
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$277/1975546571@1f1c7bf6
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$282/2021707251@5be6e01c

matchesWithDescription

Assertions Predicates in Java 驗證是否符合條件,自訂描述訊息,若不成立,則會拋出 AssertionError 。

	@Test
	public void matchesWithDescription() {
		Predicate<String> lengthGreaterThan = s -> s.length() > 3;
		System.out.println(lengthGreaterThan);
		assertThat(lengthGreaterThan).matches(p -> p.test("AssertJ"), "lengthGreaterThan");

		Predicate<Integer> greaterThan = i -> i > 10;
		System.out.println(greaterThan);
		assertThat(greaterThan).matches(p -> p.test(155), "greaterThan");
	}
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$277/1975546571@1f1c7bf6
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$282/2021707251@5be6e01c

matchesThrowError

Assertions Predicates in Java 驗證是否符合條件,自訂描述訊息,當不成立時,驗證拋出 AssertionError 。

	@Test
	public void matchesThrowError() {
		assertThatCode(() -> {
			Predicate<String> lengthGreaterThan = s -> s.length() < 3;
			System.out.println(lengthGreaterThan);
			assertThat(lengthGreaterThan).matches(p -> p.test("AssertJ"), "lengthGreaterThan");
		}).isInstanceOf(AssertionError.class);

		assertThatCode(() -> {
			Predicate<Integer> greaterThan = i -> i < 10;
			System.out.println(greaterThan);
			assertThat(greaterThan).matches(p -> p.test(155), "greaterThan");
		}).isInstanceOf(AssertionError.class);
	}
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$278/2024453272@5dd6264
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$285/23211803@72a7c7e0

satisfies

Asserting Predicates with Examples 驗證是否符合條件,若不成立,則會拋出 AssertionError 。

	@Test
	public void satisfies() {
		Predicate<String> lengthGreaterThan = s -> s.length() > 3;
		System.out.println(lengthGreaterThan);
		assertThat(lengthGreaterThan).satisfies(p -> {
			assertThat(p).accepts("AssertJ", "JUnit");
			assertThat(p).rejects("155", "151");
		});

		Predicate<Integer> greaterThan = i -> i > 10;
		System.out.println(greaterThan);
		assertThat(greaterThan).satisfies(p -> {
			assertThat(p).accepts(155, 151);
		}, p -> {
			assertThat(p).rejects(1, 2);
		});
	}
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$277/1975546571@1f1c7bf6
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$286/1704629915@76908cc0

satisfiesAnyOf

Asserting Predicates with Examples 驗證是否符合任一條件,若不成立,則會拋出 AssertionError 。

	@Test
	public void satisfiesAnyOf() {
		Predicate<String> lengthGreaterThan = s -> s.length() > 3;
		System.out.println(lengthGreaterThan);
		assertThat(lengthGreaterThan).satisfiesAnyOf(p -> {
			assertThat(p).accepts("AssertJ", "JUnit");
			assertThat(p).rejects("155", "151");
		});

		Predicate<Integer> greaterThan = i -> i > 10;
		System.out.println(greaterThan);
		assertThat(greaterThan).satisfiesAnyOf(p -> {
			assertThat(p).accepts(155, 151);
		}, p -> {
			assertThat(p).rejects(100, 200);
		});
	}
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$277/1975546571@1f1c7bf6
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$286/1704629915@76908cc0

satisfiesThrowError

Asserting Predicates with Examples 驗證是否符合條件,當不成立時,驗證拋出 AssertionError 。

	@Test
	public void satisfiesThrowError() {
		assertThatCode(() -> {
			Predicate<String> lengthGreaterThan = s -> s.length() > 3;
			System.out.println(lengthGreaterThan);
			assertThat(lengthGreaterThan).satisfies(p -> {
				assertThat(p).accepts("AssertJ", "JUnit");
				assertThat(p).rejects("9155", "9151");
			});
		}).isInstanceOf(AssertionError.class);

		assertThatCode(() -> {
			Predicate<Integer> greaterThan = i -> i > 10;
			System.out.println(greaterThan);
			assertThat(greaterThan).satisfies(p -> {
				assertThat(p).accepts(155, 151);
			}, p -> {
				assertThat(p).rejects(91, 92);
			});
		}).isInstanceOf(AssertionError.class);
	}
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$278/2024453272@5dd6264
org.ruoxue.spring_boot_168.test.assertj.predicate.AssertingPredicatesTest$$Lambda$300/820914198@31d7b7bf

AssertingPredicatesTest.java

Asserting Predicates with Examples 新增單元測試,驗證是否符合預期。

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

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

import java.util.function.Predicate;

import org.junit.jupiter.api.Test;

public class AssertingPredicatesTest {

	@Test
	public void matches() {
		Predicate<String> lengthGreaterThan = s -> s.length() > 3;
		System.out.println(lengthGreaterThan);
		assertThat(lengthGreaterThan).matches(p -> p.test("AssertJ"));

		Predicate<Integer> greaterThan = i -> i > 10;
		System.out.println(greaterThan);
		assertThat(greaterThan).matches(p -> p.test(155));
	}

	@Test
	public void matchesWithDescription() {
		Predicate<String> lengthGreaterThan = s -> s.length() > 3;
		System.out.println(lengthGreaterThan);
		assertThat(lengthGreaterThan).matches(p -> p.test("AssertJ"), "lengthGreaterThan");

		Predicate<Integer> greaterThan = i -> i > 10;
		System.out.println(greaterThan);
		assertThat(greaterThan).matches(p -> p.test(155), "greaterThan");
	}

	@Test
	public void matchesThrowError() {
		assertThatCode(() -> {
			Predicate<String> lengthGreaterThan = s -> s.length() < 3;
			System.out.println(lengthGreaterThan);
			assertThat(lengthGreaterThan).matches(p -> p.test("AssertJ"), "lengthGreaterThan");
		}).isInstanceOf(AssertionError.class);

		assertThatCode(() -> {
			Predicate<Integer> greaterThan = i -> i < 10;
			System.out.println(greaterThan);
			assertThat(greaterThan).matches(p -> p.test(155), "greaterThan");
		}).isInstanceOf(AssertionError.class);
	}

	@Test
	public void satisfies() {
		Predicate<String> lengthGreaterThan = s -> s.length() > 3;
		System.out.println(lengthGreaterThan);
		assertThat(lengthGreaterThan).satisfies(p -> {
			assertThat(p).accepts("AssertJ", "JUnit");
			assertThat(p).rejects("155", "151");
		});

		Predicate<Integer> greaterThan = i -> i > 10;
		System.out.println(greaterThan);
		assertThat(greaterThan).satisfies(p -> {
			assertThat(p).accepts(155, 151);
		}, p -> {
			assertThat(p).rejects(1, 2);
		});
	}

	@Test
	public void satisfiesAnyOf() {
		Predicate<String> lengthGreaterThan = s -> s.length() > 3;
		System.out.println(lengthGreaterThan);
		assertThat(lengthGreaterThan).satisfiesAnyOf(p -> {
			assertThat(p).accepts("AssertJ", "JUnit");
			assertThat(p).rejects("155", "151");
		});

		Predicate<Integer> greaterThan = i -> i > 10;
		System.out.println(greaterThan);
		assertThat(greaterThan).satisfiesAnyOf(p -> {
			assertThat(p).accepts(155, 151);
		}, p -> {
			assertThat(p).rejects(100, 200);
		});
	}

	@Test
	public void satisfiesThrowError() {
		assertThatCode(() -> {
			Predicate<String> lengthGreaterThan = s -> s.length() > 3;
			System.out.println(lengthGreaterThan);
			assertThat(lengthGreaterThan).satisfies(p -> {
				assertThat(p).accepts("AssertJ", "JUnit");
				assertThat(p).rejects("9155", "9151");
			});
		}).isInstanceOf(AssertionError.class);

		assertThatCode(() -> {
			Predicate<Integer> greaterThan = i -> i > 10;
			System.out.println(greaterThan);
			assertThat(greaterThan).satisfies(p -> {
				assertThat(p).accepts(155, 151);
			}, p -> {
				assertThat(p).rejects(91, 92);
			});
		}).isInstanceOf(AssertionError.class);
	}
}

心得分享

Testing Java Predicates with AssertJ 快速檢查物件是否滿足所有提供的斷言,搭配使用 Predicate 與 ThrowingConsumer 等接口,根據 lambda 表達式調用,驗證是否成立,若不成立,則會拋出 AssertionError, Asserting Predicates with Examples 介紹 matches 、 satisfies 等方法,提供範例參考。

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