Junit 5 Assumptions

While testing our code, we might come across a scenario where some conditions must be true or false, then only we will continue with tests otherwise not. for that JUnit 5 provides assumptions, if our assumption is true, then only proceed further otherwise aborted.

The assumption class provides the following overloaded methods.

• assumeFalse
• assumeTrue
• assumingThat

package com.example.junit5.sujan;

public class AppleCalculator {
    public int addApple(int appleBag1, int appleBag2) {
        return appleBag1 + appleBag2;
    }

    public String getApple() {
        return "apple";
    }
}

package com.example.junit5.sujan;

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assumptions.*;

class AppleCalculatorTest {

    @Test
    void assumeTrueTest() {
        AppleCalculator appleCalculator = new AppleCalculator();
        assumeTrue("apple".equalsIgnoreCase(appleCalculator.getApple()));
        assertEquals(2, appleCalculator.addApple(1, 1), "1 apple + 1 apple is 2 apple");
    }

    @Test
    void assumeTrueMessageTest() {
        AppleCalculator appleCalculator = new AppleCalculator();
        assumeTrue("apple".equalsIgnoreCase(appleCalculator.getApple()), "apple is equal to apple");
        assertEquals(2, appleCalculator.addApple(1, 1), "1 apple + 1 apple is 2 apple");
    }

    @Test
    void assumeTrueLambdaTest() {
        AppleCalculator appleCalculator = new AppleCalculator();
        assumingThat("apple".equalsIgnoreCase(appleCalculator.getApple()), () -> assertEquals(2, appleCalculator.addApple(1, 1), "1 apple + 1 apple is 2 apple"));
    }

    @Test
    void assumeFalseTest() {
        AppleCalculator appleCalculator = new AppleCalculator();
        assumeFalse("oranges".equalsIgnoreCase(appleCalculator.getApple()));
        assertEquals(4, appleCalculator.addApple(2, 2), "2 apple + 2 apple is 4 apple");
    }

    @Test
    void assumeFalseMessageTest() {
        AppleCalculator appleCalculator = new AppleCalculator();
        assumeFalse("oranges".equalsIgnoreCase(appleCalculator.getApple()), "apple is not equal to oranges");
        assertEquals(4, appleCalculator.addApple(2, 2), "2 apple + 2 apple is 4 apple");
    }

    @Test
    void assumeFalseLambdaTest() {
        AppleCalculator appleCalculator = new AppleCalculator();
        assumingThat("orange".equalsIgnoreCase(appleCalculator.getApple()), () -> assertEquals(2, appleCalculator.addApple(1, 1), "1 apple + 1 apple is 2 apple"));
    }
}

plugins {
    id 'java'
}

group 'org.example'
version '1.0-SNAPSHOT'

repositories {
    mavenCentral()
}

dependencies {
    testImplementation('org.junit.jupiter:junit-jupiter:5.6.2')
}