Parallel Test Logger

The biggest pain when running parallel tests is messy, spaghetti-like logs. Let’s fix this!

Supported for TestNG.

Install

Add to your pom:

<dependency>
    <groupId>io.github.amerousful</groupId>
    <artifactId>parallel-test-logger</artifactId>
    <version>1.4.5</version>
</dependency>

Import:

import static logger.LoggerFactory.log;

How does it work?

Before the test begins, the logger is initialized based on the thread ID and the test name. During the test, all logs are appended to a buffer. Once the test ends, the logs are retrieved from the buffer.

Example:

Let's define a simple test class with multiple tests and execute them in parallel.

import static logger.LoggerFactory.log;

public class ParallelTestSample {


    @Test
    void firstTest() {
        log().info("first 1");
        log().info("first 2");
        log().info("first 3");
    }

    @Test
    void secondTest() {
        log().info("second 1");
        log().info("second 2");
        log().info("second 3");
    }

    @Test
    void third() {
        log().info("third 1");
        log().info("third 2");
        log().info("third 3");
    }

}

Run the xml with parallel="methods" thread-count="3"

---

Stdout will be chaotic and mixed:

[INFO] 14:18:42 ParallelTestSample.third()- third 1
[INFO] 14:18:42 ParallelTestSample.secondTest()- second 1
[INFO] 14:18:42 ParallelTestSample.firstTest()- first 1
[INFO] 14:18:42 ParallelTestSample.secondTest()- second 2
[INFO] 14:18:42 ParallelTestSample.third()- third 2
[INFO] 14:18:42 ParallelTestSample.secondTest()- second 3
[INFO] 14:18:42 ParallelTestSample.firstTest()- first 2
[INFO] 14:18:42 ParallelTestSample.third()- third 3
[INFO] 14:18:42 ParallelTestSample.firstTest()- first 3

Ok, now we define the parallel listener and run it again.

import listeners.ParallelListener;

@Listeners({ParallelListener.class})
public class ParallelTestSample {

}

Result:

--- [START] Test: third | Thread id: 14] ---
t:14 [INFO] 15:47:33 ParallelTestSample.third()- third 1
t:14 [INFO] 15:47:33 ParallelTestSample.third()- third 2
t:14 [INFO] 15:47:33 ParallelTestSample.third()- third 3
--- [END] Test: third | Thread id: 14] ---

 --- [START] Test: firstTest | Thread id: 12] ---
t:12 [INFO] 15:47:33 ParallelTestSample.firstTest()- first 1
t:12 [INFO] 15:47:33 ParallelTestSample.firstTest()- first 2
t:12 [INFO] 15:47:33 ParallelTestSample.firstTest()- first 3
--- [END] Test: firstTest | Thread id: 12] ---

 --- [START] Test: secondTest | Thread id: 13] ---
t:13 [INFO] 15:47:33 ParallelTestSample.secondTest()- second 1
t:13 [INFO] 15:47:33 ParallelTestSample.secondTest()- second 2
t:13 [INFO] 15:47:33 ParallelTestSample.secondTest()- second 3
--- [END] Test: secondTest | Thread id: 13] ---

---

Don't initial the logger for a class and use in static methods!
Call log() in static methods and tests.

Bad:

import logger.LoggerFactory;
import org.apache.log4j.Logger;

public class Utils {

   static Logger logger = LoggerFactory.log();

    static void staticMethod() {
        logger.info("bad...");
    }
}

Good:

import static logger.LoggerFactory.log;

public class Utils {
    
    static void staticMethod() {
        log().info("yeap!");
    }
}

---

The Logger can be configured using a properties file. Just create a file src/test/resources/parallel_log.properties Available options:

• pattern [for parallel]
• single_pattern
• allure [true | false]

Example:

pattern=t:%X{threadId} [%p] %d{HH:mm:ss} [%C{1} L:%L]- %m%n
allure=true