Asserting Optionals with AssertJ

內容目錄

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 Optionals 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
       |                       +- optional
       |                           +- AssertingOptionalsTest.java

單元測試

Assertions Optionals in Java 斷言 Optional 的主要目的是取得 Optional 以進行斷言。

matches

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

	@Test
	public void matches() {
		Optional<String> value = Optional.of("AssertJ");
		System.out.println(value);
		assertThat(value).matches(o -> o.isPresent());

		Optional<Integer> intValue = Optional.of(155);
		System.out.println(intValue);
		assertThat(intValue).matches(o -> o.get() != null);
	}

Optional[AssertJ]
Optional[155]

matchesWithDescription

Assertions Optionals 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() {
		Optional<String> value = Optional.of("AssertJ");
		System.out.println(value);
		assertThat(value).matches(o -> o.isPresent(), "isPresent");

		Optional<Integer> intValue = Optional.of(155);
		System.out.println(intValue);
		assertThat(intValue).matches(o -> o.get() != null, "notNull");
	}

Optional[AssertJ]
Optional[155]

matchesThrowError

Assertions Optionals 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(() -> {
			Optional<String> value = Optional.of("AssertJ");
			System.out.println(value);
			assertThat(value).matches(o -> false == o.isPresent(), "isPresent");
		}).isInstanceOf(AssertionError.class);

		assertThatCode(() -> {
			Optional<Integer> intValue = Optional.of(155);
			System.out.println(intValue);
			assertThat(intValue).matches(o -> o.get() == null, "notNull");
		}).isInstanceOf(AssertionError.class);
	}

Optional[AssertJ]
Optional[155]

satisfies

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

	@Test
	public void satisfies() {
		Optional<String> value = Optional.of("AssertJ");
		System.out.println(value);
		assertThat(value).satisfies(o -> {
			assertThat(o).isNotEmpty();
			assertThat(o).hasValue("AssertJ");
		});

		Optional<Integer> intValue = Optional.of(155);
		System.out.println(intValue);
		assertThat(intValue).satisfies(o -> {
			assertThat(o).isNotNull();
		}, o -> {
			assertThat(o).isIn(Optional.of(151), Optional.of(155));
		});
	}

Optional[AssertJ]
Optional[155]

satisfiesAnyOf

Asserting Optionals 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() {
		Optional<String> value = Optional.of("AssertJ");
		System.out.println(value);
		assertThat(value).satisfiesAnyOf(o -> {
			assertThat(o).isNotEmpty();
			assertThat(o).hasValue("AssertJ");
		});

		Optional<Integer> intValue = Optional.of(155);
		System.out.println(intValue);
		assertThat(intValue).satisfiesAnyOf(o -> {
			assertThat(o).isNotNull();
		}, o -> {
			assertThat(o).isIn(Optional.of(0), Optional.of(1));
		});
	}

Optional[AssertJ]
Optional[155]

satisfiesThrowError

Asserting Optionals 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(() -> {
			Optional<String> value = Optional.of("AssertJ");
			System.out.println(value);
			assertThat(value).satisfies(o -> {
				assertThat(o).isNotEmpty();
				assertThat(o).hasValue("155");
			});
		}).isInstanceOf(AssertionError.class);

		assertThatCode(() -> {
			Optional<Integer> intValue = Optional.of(155);
			System.out.println(intValue);
			assertThat(intValue).satisfies(o -> {
				assertThat(o).isNotNull();
			}, o -> {
				assertThat(o).isIn(Optional.of(151), Optional.of(165));
			});
		}).isInstanceOf(AssertionError.class);
	}

Optional[AssertJ]
Optional[155]

AssertingOptionalsTest.java

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

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

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

import java.util.Optional;

import org.junit.jupiter.api.Test;

public class AssertingOptionalsTest {

	@Test
	public void matches() {
		Optional<String> value = Optional.of("AssertJ");
		System.out.println(value);
		assertThat(value).matches(o -> o.isPresent());

		Optional<Integer> intValue = Optional.of(155);
		System.out.println(intValue);
		assertThat(intValue).matches(o -> o.get() != null);
	}

	@Test
	public void matchesWithDescription() {
		Optional<String> value = Optional.of("AssertJ");
		System.out.println(value);
		assertThat(value).matches(o -> o.isPresent(), "isPresent");

		Optional<Integer> intValue = Optional.of(155);
		System.out.println(intValue);
		assertThat(intValue).matches(o -> o.get() != null, "notNull");
	}

	@Test
	public void matchesThrowError() {
		assertThatCode(() -> {
			Optional<String> value = Optional.of("AssertJ");
			System.out.println(value);
			assertThat(value).matches(o -> false == o.isPresent(), "isPresent");
		}).isInstanceOf(AssertionError.class);

		assertThatCode(() -> {
			Optional<Integer> intValue = Optional.of(155);
			System.out.println(intValue);
			assertThat(intValue).matches(o -> o.get() == null, "notNull");
		}).isInstanceOf(AssertionError.class);
	}

	@Test
	public void satisfies() {
		Optional<String> value = Optional.of("AssertJ");
		System.out.println(value);
		assertThat(value).satisfies(o -> {
			assertThat(o).isNotEmpty();
			assertThat(o).hasValue("AssertJ");
		});

		Optional<Integer> intValue = Optional.of(155);
		System.out.println(intValue);
		assertThat(intValue).satisfies(o -> {
			assertThat(o).isNotNull();
		}, o -> {
			assertThat(o).isIn(Optional.of(151), Optional.of(155));
		});
	}

	@Test
	public void satisfiesAnyOf() {
		Optional<String> value = Optional.of("AssertJ");
		System.out.println(value);
		assertThat(value).satisfiesAnyOf(o -> {
			assertThat(o).isNotEmpty();
			assertThat(o).hasValue("AssertJ");
		});

		Optional<Integer> intValue = Optional.of(155);
		System.out.println(intValue);
		assertThat(intValue).satisfiesAnyOf(o -> {
			assertThat(o).isNotNull();
		}, o -> {
			assertThat(o).isIn(Optional.of(0), Optional.of(1));
		});
	}

	@Test
	public void satisfiesThrowError() {
		assertThatCode(() -> {
			Optional<String> value = Optional.of("AssertJ");
			System.out.println(value);
			assertThat(value).satisfies(o -> {
				assertThat(o).isNotEmpty();
				assertThat(o).hasValue("155");
			});
		}).isInstanceOf(AssertionError.class);

		assertThatCode(() -> {
			Optional<Integer> intValue = Optional.of(155);
			System.out.println(intValue);
			assertThat(intValue).satisfies(o -> {
				assertThat(o).isNotNull();
			}, o -> {
				assertThat(o).isIn(Optional.of(151), Optional.of(165));
			});
		}).isInstanceOf(AssertionError.class);
	}
}

心得分享

Testing Java Optionals 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 Optionals with Examples 介紹 matches 、 satisfies 等方法，提供範例參考。