TimingExtension.java

package org.junit5test

import java.lang.reflect.Method;
import java.util.logging.Logger;

import org.junit.jupiter.api.extension.*;
import org.junit.jupiter.api.extension.ExtensionContext.Namespace;
import org.junit.jupiter.api.extension.ExtensionContext.Store;

public class TimingExtension implements BeforeEachCallback, BeforeTestExecutionCallback, AfterTestExecutionCallback, AfterEachCallback {

    private static final Logger logger = Logger.getLogger(TimingExtension.class.getName());

    private static final String BEFORE_EACH_TIME = "before each";
    private static final String BEFORE_TEST_TIME = "before test";
    private static final String AFTER_TEST_TIME = "after test";

    @Override
    public void beforeEach(ExtensionContext context) {
        getStore(context).put(BEFORE_EACH_TIME, System.currentTimeMillis());
    }

    @Override
    public void beforeTestExecution(ExtensionContext context) {
        getStore(context).put(BEFORE_TEST_TIME, System.currentTimeMillis());
    }

    @Override
    public void afterTestExecution(ExtensionContext context) {
        getStore(context).put(AFTER_TEST_TIME, System.currentTimeMillis());
    }

    @Override
    public void afterEach(ExtensionContext context) {
        Method testMethod = context.getRequiredTestMethod();
        long afterEachTime = System.currentTimeMillis();
        long beforeEachTime = getStore(context).remove(BEFORE_EACH_TIME, long.class);
        long beforeTestTime = getStore(context).remove(BEFORE_TEST_TIME, long.class);
        long afterTestTime = getStore(context).remove(AFTER_TEST_TIME, long.class);
        long beforeEachDuration = beforeTestTime - beforeEachTime;
        long testDuration = afterTestTime - beforeTestTime;
        long afterEachDuration = afterEachTime - afterTestTime;

        logger.info(() ->
            String.format("Method [%s] beforeEach %s ms; test %s ms; after %s ms", testMethod.getName(), beforeEachDuration, testDuration, afterEachDuration));

    }

    private Store getStore(ExtensionContext context) {
        return context.getStore(Namespace.create(getClass(), context.getRequiredTestMethod()));
    }
}