DZone
Thanks for visiting DZone today,
Edit Profile
  • Manage Email Subscriptions
  • How to Post to DZone
  • Article Submission Guidelines
Sign Out View Profile
  • Post an Article
  • Manage My Drafts
Over 2 million developers have joined DZone.
Log In / Join
Refcards Trend Reports Events Over 2 million developers have joined DZone. Join Today! Thanks for visiting DZone today,
Edit Profile Manage Email Subscriptions Moderation Admin Console How to Post to DZone Article Submission Guidelines
View Profile
Sign Out
Refcards
Trend Reports
Events
Zones
Culture and Methodologies Agile Career Development Methodologies Team Management
Data Engineering AI/ML Big Data Data Databases IoT
Software Design and Architecture Cloud Architecture Containers Integration Microservices Performance Security
Coding Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Partner Zones AWS Cloud
by AWS Developer Relations
Culture and Methodologies
Agile Career Development Methodologies Team Management
Data Engineering
AI/ML Big Data Data Databases IoT
Software Design and Architecture
Cloud Architecture Containers Integration Microservices Performance Security
Coding
Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance
Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Partner Zones
AWS Cloud
by AWS Developer Relations
Securing Your Software Supply Chain with JFrog and Azure
Register Today

Trending

  • Decoding ChatGPT: The Concerns We All Should Be Aware Of
  • Extending Java APIs: Add Missing Features Without the Hassle
  • New ORM Framework for Kotlin
  • Observability Architecture: Financial Payments Introduction

Trending

  • Decoding ChatGPT: The Concerns We All Should Be Aware Of
  • Extending Java APIs: Add Missing Features Without the Hassle
  • New ORM Framework for Kotlin
  • Observability Architecture: Financial Payments Introduction
  1. DZone
  2. Testing, Deployment, and Maintenance
  3. Testing, Tools, and Frameworks
  4. Unit testing : Asserting that a line was logged by Logback

Unit testing : Asserting that a line was logged by Logback

Aurelien Broszniowski user avatar by
Aurelien Broszniowski
·
Dec. 02, 11 · Interview
Like (1)
Save
Tweet
Share
73.23K Views

Join the DZone community and get the full member experience.

Join For Free

I encountered a tricky problem today, I was writing a test for which the assertion was onto some function called or not. I couldn’t mock that function as it was part of an external API for which I couldn’t change the real Object to a mocked Object.

There was a solution, checking that this function was logging a particular event or not. So in order to assert that this specific line was logged or not, I added a mocked Appender. (Note: The Appender is the class that will actually do the logging, e.g. ConsoleAppender to log to the console)

I’m using two great libraries here: Mockito and Logback, please refer to my other post explaining how to configure Logback.

Here is the code:

package com.jsoft.test;

import ch.qos.logback.classic.spi.LoggingEvent;
import ch.qos.logback.core.Appender;
import org.mockito.ArgumentMatcher;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.junit.Test;

import static org.mockito.Matchers.argThat;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

public class MyTest {
  private static Logger logger = LoggerFactory.getLogger(MyTest.class);

    @Test
    public void testSomething() {
    ch.qos.logback.classic.Logger root = (ch.qos.logback.classic.Logger) LoggerFactory.getLogger(ch.qos.logback.classic.Logger.ROOT_LOGGER_NAME);
    final Appender mockAppender = mock(Appender.class);
    when(mockAppender.getName()).thenReturn("MOCK");
    root.addAppender(mockAppender);

    //... do whatever you need to trigger the log

    verify(mockAppender).doAppend(argThat(new ArgumentMatcher() {
      @Override
      public boolean matches(final Object argument) {
        return ((LoggingEvent)argument).getFormattedMessage().contains("Hey this is the message I want to see");
      }
    }));
  }
}

 

From http://jsoftbiz.wordpress.com/2011/11/29/unit-testing-asserting-that-a-line-was-logged-by-logback/

unit test

Opinions expressed by DZone contributors are their own.

Trending

  • Decoding ChatGPT: The Concerns We All Should Be Aware Of
  • Extending Java APIs: Add Missing Features Without the Hassle
  • New ORM Framework for Kotlin
  • Observability Architecture: Financial Payments Introduction

Comments

Partner Resources

X

ABOUT US

  • About DZone
  • Send feedback
  • Careers
  • Sitemap

ADVERTISE

  • Advertise with DZone

CONTRIBUTE ON DZONE

  • Article Submission Guidelines
  • Become a Contributor
  • Visit the Writers' Zone

LEGAL

  • Terms of Service
  • Privacy Policy

CONTACT US

  • 600 Park Offices Drive
  • Suite 300
  • Durham, NC 27709
  • support@dzone.com

Let's be friends: