LoggerTest.java

/*
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2026, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v2.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.classic;


import java.util.List;

import org.junit.jupiter.api.Test;
import org.slf4j.LoggerFactory;

import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.read.ListAppender;
import ch.qos.logback.core.status.Status;
import org.slf4j.spi.LoggingEventBuilder;
import org.slf4j.spi.NOPLoggingEventBuilder;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.Assertions.fail;

public class LoggerTest {

    LoggerContext lc = new LoggerContext();
    Logger root = lc.getLogger(Logger.ROOT_LOGGER_NAME);
    Logger loggerTest = lc.getLogger(LoggerTest.class);

    ListAppender<ILoggingEvent> listAppender = new ListAppender<ILoggingEvent>();

    @Test
    public void smoke() {
        ListAppender<ILoggingEvent> listAppender = new ListAppender<ILoggingEvent>();
        listAppender.start();
        root.addAppender(listAppender);
        Logger logger = lc.getLogger(LoggerTest.class);
        assertEquals(0, listAppender.list.size());
        logger.debug("hello");
        assertEquals(1, listAppender.list.size());
    }

    @Test
    public void testNoStart() {
        // listAppender.start();
        listAppender.setContext(lc);
        root.addAppender(listAppender);
        Logger logger = lc.getLogger(LoggerTest.class);
        logger.debug("hello");

        List<Status> statusList = lc.getStatusManager().getCopyOfStatusList();
        Status s0 = statusList.get(0);
        assertEquals(Status.WARN, s0.getLevel());
        assertTrue(s0.getMessage().startsWith("Attempted to append to non started"));
    }

    @Test
    public void testAdditive() {
        listAppender.start();
        root.addAppender(listAppender);
        loggerTest.addAppender(listAppender);
        loggerTest.setAdditive(false);
        loggerTest.debug("hello");
        // 1 instead of two, since logger is not additive
        assertEquals(1, listAppender.list.size());
    }

    @Test
    public void testRootLogger() {
        Logger logger = (Logger) LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME);
        LoggerContext lc = logger.getLoggerContext();

        assertNotNull(logger, "Returned logger is null");
        assertEquals(logger.getName(), Logger.ROOT_LOGGER_NAME, "Return logger isn't named root");
        assertTrue(logger == lc.root, "logger instances should be indentical");
    }

    @Test
    public void testBasicFiltering() throws Exception {
        listAppender.start();
        root.addAppender(listAppender);
        root.setLevel(Level.INFO);
        loggerTest.debug("x");
        assertEquals(0, listAppender.list.size());
        loggerTest.info("x");
        loggerTest.warn("x");
        loggerTest.error("x");
        assertEquals(3, listAppender.list.size());
    }

    void checkLevelThreshold(Logger logger, Level threshold) {

        if (Level.ERROR_INT >= threshold.levelInt) {
            assertTrue(logger.isErrorEnabled());
            assertTrue(logger.isEnabledFor(Level.ERROR));
        } else {
            assertFalse(logger.isErrorEnabled());
            assertFalse(logger.isEnabledFor(Level.ERROR));
        }

        if (Level.WARN_INT >= threshold.levelInt) {
            assertTrue(logger.isWarnEnabled());
            assertTrue(logger.isEnabledFor(Level.WARN));
        } else {
            assertFalse(logger.isWarnEnabled());
            assertFalse(logger.isEnabledFor(Level.WARN));
        }
        if (Level.INFO_INT >= threshold.levelInt) {
            assertTrue(logger.isInfoEnabled());
            assertTrue(logger.isEnabledFor(Level.INFO));
        } else {
            assertFalse(logger.isInfoEnabled());
            assertFalse(logger.isEnabledFor(Level.INFO));
        }
        if (Level.DEBUG_INT >= threshold.levelInt) {
            assertTrue(logger.isDebugEnabled());
            assertTrue(logger.isEnabledFor(Level.DEBUG));
        } else {
            assertFalse(logger.isDebugEnabled());
            assertFalse(logger.isEnabledFor(Level.DEBUG));
        }
        if (Level.TRACE_INT >= threshold.levelInt) {
            assertTrue(logger.isTraceEnabled());
            assertTrue(logger.isEnabledFor(Level.TRACE));
        } else {
            assertFalse(logger.isTraceEnabled());
            assertFalse(logger.isEnabledFor(Level.TRACE));
        }
    }

    @Test
    public void innerClass_I() {
        root.setLevel(Level.DEBUG);
        Logger a = lc.getLogger("a");
        a.setLevel(Level.INFO);
        Logger a_b = lc.getLogger("a$b");
        assertEquals(Level.INFO, a_b.getEffectiveLevel());
    }

    @Test
    public void innerClass_II() {
        root.setLevel(Level.DEBUG);
        Logger a = lc.getLogger(this.getClass());
        a.setLevel(Level.INFO);
        Logger a_b = lc.getLogger(new Inner().getClass());
        assertEquals(Level.INFO, a_b.getEffectiveLevel());
    }

    class Inner {
    }

    @Test
    public void testEnabled_All() throws Exception {
        root.setLevel(Level.TRACE);
        checkLevelThreshold(loggerTest, Level.TRACE);
    }

    @Test
    public void fluentAPIAtDisabledDebugLevelShouldReturnNOPLoggingEventBuilder() throws Exception {
        root.setLevel(Level.INFO);
        LoggingEventBuilder leb = loggerTest.atLevel(org.slf4j.event.Level.DEBUG);
        assertEquals(NOPLoggingEventBuilder.class, leb.getClass());
    }

    @Test
    public void testEnabled_Debug() throws Exception {
        root.setLevel(Level.DEBUG);
        checkLevelThreshold(loggerTest, Level.DEBUG);
    }

    @Test
    public void testEnabled_Info() throws Exception {
        root.setLevel(Level.INFO);
        checkLevelThreshold(loggerTest, Level.INFO);
    }

    @Test
    public void testEnabledX_Warn() throws Exception {
        root.setLevel(Level.WARN);
        checkLevelThreshold(loggerTest, Level.WARN);
    }

    public void testEnabledX_Errror() throws Exception {
        root.setLevel(Level.ERROR);
        checkLevelThreshold(loggerTest, Level.ERROR);
    }

    @Test
    public void testEnabledX_Off() throws Exception {
        root.setLevel(Level.OFF);
        checkLevelThreshold(loggerTest, Level.OFF);
    }

    @Test
    public void setRootLevelToNull() {
        try {
            root.setLevel(null);
            fail("The level of the root logger should not be settable to null");
        } catch (IllegalArgumentException e) {
        }
    }

    @Test
    public void setLevelToNull_A() {
        loggerTest.setLevel(null);
        assertEquals(root.getEffectiveLevel(), loggerTest.getEffectiveLevel());
    }

    @Test
    public void setLevelToNull_B() {
        loggerTest.setLevel(Level.DEBUG);
        loggerTest.setLevel(null);
        assertEquals(root.getEffectiveLevel(), loggerTest.getEffectiveLevel());
    }

    @Test
    public void setLevelToNull_LBCLASSIC_91() {
        loggerTest.setLevel(Level.DEBUG);
        ch.qos.logback.classic.Logger child = lc.getLogger(loggerTest.getName() + ".child");
        loggerTest.setLevel(null);
        assertEquals(root.getEffectiveLevel(), loggerTest.getEffectiveLevel());
        assertEquals(root.getEffectiveLevel(), child.getEffectiveLevel());
    }

}