JaCoCo Maven Plugin

6 분 소요

Maven Lifecycle and Plugins for Test

1. JaCoCo(Java Code Coverage)

Java 기반의 어플리케이션 테스트에 적용할 수 있는 리포트(report) 도구입니다. 코드 커버리지(code coverage)는 테스트 코드가 구현체 코드 전체 중 얼만큼 실행시켰는지에 대한 지표입니다. JaCoCo는 코드 커버리지에 대한 리포트를 만들어 주는 것이 주된 목적입니다.

JaCoCo is a free code coverage library for Java, which has been created by the EclEmma team based on the lessons learned from using and integration existing libraries for many years.

2. Maven Plugin JaCoCo

메이븐 플러그인으로 JaCoCo를 추가한 후 골(goal)을 등록할 수 있습니다. 메이븐 골로 등록하면 CLI(command line interface)를 통해 동작을 자동화시킬 수 있습니다.

2.1. pom.xml

설정 파일의 전체 모습을 보고, 각 설정 별로 자세하게 살펴보겠습니다.

    <plugin>
        <groupId>org.jacoco</groupId>
        <artifactId>jacoco-maven-plugin</artifactId>
        <version>0.8.8</version>
        <configuration>
            <excludes>
                <exclude>**/action/in/blog/*Application.class</exclude>
            </excludes>
        </configuration>
        <executions>
            <execution>
                <id>jacoco-prepare-agent</id>
                <goals>
                    <goal>prepare-agent</goal>
                </goals>
            </execution>
            <execution>
                <id>jacoco-report</id>
                <goals>
                    <goal>report</goal>
                </goals>
            </execution>
            <execution>
                <id>jacoco-check</id>
                <goals>
                    <goal>check</goal>
                </goals>
                <configuration>
                    <rules>
                        <rule>
                            <element>BUNDLE</element>
                            <limits>
                                <limit>
                                    <counter>INSTRUCTION</counter>
                                    <value>COVEREDRATIO</value>
                                    <minimum>0.80</minimum>
                                </limit>
                            </limits>
                        </rule>
                        <rule>
                            <element>METHOD</element>
                            <limits>
                                <limit>
                                    <counter>LINE</counter>
                                    <value>TOTALCOUNT</value>
                                    <maximum>30</maximum>
                                </limit>
                            </limits>
                        </rule>
                    </rules>
                </configuration>
            </execution>
        </executions>
    </plugin>

2.2. Exclude Code

특정 코드를 테스트 커버리지 측정에서 제외할 수 있습니다. 해당 포스트에선 main 메소드가 포함된 ActionInBlogApplication 클래스는 제외하였습니다.

    <configuration>
        <excludes>
            <exclude>**/action/in/blog/*Application.class</exclude>
        </excludes>
    </configuration>

2.3. Goals

JaCoCo 플러그인을 사용하면 다음과 같은 골들을 설정할 수 있습니다.

help
- jacoco-maven-plugin 사용을 위한 도움말을 볼 수 있습니다.
prepare-agent
- JaCoCo 런타임 에이전트에게 테스트 커버리지 측정을 위한 JVM 실행 인수들을 전달합니다.
- 해당 골을 정의해야지 테스트 커버리지를 측정할 수 있습니다.
- maven-surefire-plugin와 함께 사용할 수 있습니다.
prepare-agent-integration
- prepare-agent와 동일하지만, 결합 테스트(integration test)에 적합합니다.
merge
- 실행 데이터 파일 집합을 단일 파일로 병합합니다.
report
- 단일 프로젝트에서 테스트에 대한 코드 커버리지 리포트를 다양한 형식으로 만들어냅니다.
- HTML, XML, CSV
report-integration
- report와 동일하지만, 결합 테스트에 적합합니다.
report-aggregate
- 다중 프로젝트에서 테스트에 대한 코드 커버리지 리포트를 다양한 형식으로 만들어냅니다.
- HTML, XML, CSV
check
- 코드 커버리지 메트릭(metric)이 충족되는지 확인합니다.
- 쉽게 설명하면 코드 커버리지에 대한 기준을 정의합니다.
dump
- TCP 서버 모드에서 실행 중인 JaCoCo 에이전트로부터 덤프(dump)를 요청합니다.
instrument
- 오프라인(offline) 측정을 수행하는 명령입니다.
restore-instrumented-classes
- 오프라인 측정 이전에 원본 파일들을 저장합니다.

2.4. Rules

check 골 하위에 코드 커버리지에 대한 기준을 정의할 수 있습니다. 다음과 같은 기준들이 존재합니다.

Element type
- 코드 커버리지를 체크하는 기준이며 다음과 같은 기준들이 존재합니다.
- BUNDLE(default)
- PACKAGE
- CLASS
- SOURCEFILE
- METHOD
Counter
- 코드 커버리지를 측정할 때 사용하는 지표이며 다음과 같은 지표들이 존재합니다.
- LINE
- BRANCH
- CLASS
- METHOD
- INSTRUCTION(default)
- COMPLEXITY
Value
- 코드 커버리지에 대한 결과를 표시하는 방법입니다.
- TOTALCOUNT
- MISSEDCOUNT
- COVEREDCOUNT
- MISSEDRATIO
- COVEREDRATIO(default)

Example of Rules

1번 기준
- 패키지 번들 단위로 확인합니다.
- 코드 커버리지 비율이 Java 바이트 코드 명령어 개수를 기준으로 80%가 넘지 못하면 실패입니다.
2번 기준
- 메소드 단위로 확인합니다.
- 메소드의 코드 라인이 총 30줄이 넘어가면 실패입니다.

    <execution>
        <id>jacoco-check</id>
        <goals>
            <goal>check</goal>
        </goals>
        <configuration>
            <rules>
                <rule>
                    <element>BUNDLE</element>
                    <limits>
                        <limit>
                            <counter>INSTRUCTION</counter>
                            <value>COVEREDRATIO</value>
                            <minimum>0.80</minimum>
                        </limit>
                    </limits>
                </rule>
                <rule>
                    <element>METHOD</element>
                    <limits>
                        <limit>
                            <counter>LINE</counter>
                            <value>TOTALCOUNT</value>
                            <maximum>30</maximum>
                        </limit>
                    </limits>
                </rule>
            </rules>
        </configuration>
    </execution>

3. Practice

JaCoCo가 정상적으로 동작하는지 확인해보겠습니다.

3.1. System Under Test and Test Codes

간단한 테스트 대상 클래스와 테스트 코드를 준비합니다.

3.1.1. Calculator Class

package action.in.blog.util;

public class Calculator {

    public int sum(int num1, int num2) {
        return num1 + num2;
    }

    public int subtract(int num1, int num2) {
        return num1 - num2;
    }

    public boolean isNull(Object obj) {
        return obj == null;
    }
}

3.1.2. CalculatorTests Class

package action.in.blog.util;

import org.junit.jupiter.api.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.equalTo;

public class CalculatorTests {

    @Test
    void sum() {
        Calculator sut = new Calculator();
        assertThat(sut.sum(1, 2), equalTo(3));
    }

    @Test
    void subtract() {
        Calculator sut = new Calculator();
        assertThat(sut.subtract(1, 2), equalTo(-1));
    }

    @Test
    void isNull() {
        Calculator sut = new Calculator();
        assertThat(sut.isNull(new Object()), equalTo(false));
        assertThat(sut.isNull(null), equalTo(true));
    }
}

3.2. Run Maven Phase

테스트에 대한 코드 커버리지 측정은 테스트 페이즈(phase)를 실행하는 페이즈들부터 가능합니다.

test
package
integration-test
verify
install
deploy

Run Install Phase

실행 중간에 jacoco-maven-plugin에 정의한 골들이 실행되면서 코드 커버리지 리포트를 생성합니다.
initialize 페이즈에서 report 골이 실행됩니다.
test 페이즈에서 report 골이 실행됩니다.
verify 페이즈에서 check 골이 실행됩니다.

$ mvn install

[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------< action.in.blog:action-in-blog >--------------------
[INFO] Building action-in-blog 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- jacoco-maven-plugin:0.8.8:prepare-agent (jacoco-prepare-agent) @ action-in-blog ---
[INFO] argLine set to -javaagent:/Users/junhyunk/.m2/repository/org/jacoco/org.jacoco.agent/0.8.8/org.jacoco.agent-0.8.8-runtime.jar=destfile=/Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/jacoco.exec,excludes=**/action/in/blog/*Application.class
[INFO] 
[INFO] --- maven-resources-plugin:3.3.0:resources (default-resources) @ action-in-blog ---
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO] 
[INFO] --- maven-compiler-plugin:3.10.1:compile (default-compile) @ action-in-blog ---
[INFO] Nothing to compile - all classes are up to date
[INFO] 
[INFO] --- maven-resources-plugin:3.3.0:testResources (default-testResources) @ action-in-blog ---
[INFO] skip non existing resourceDirectory /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/src/test/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.10.1:testCompile (default-testCompile) @ action-in-blog ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/test-classes
[INFO] 
[INFO] --- maven-surefire-plugin:2.22.2:test (default-test) @ action-in-blog ---
[INFO] 
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running action.in.blog.util.CalculatorTests
[INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.034 s - in action.in.blog.util.CalculatorTests
[INFO] 
[INFO] Results:
[INFO] 
[INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0
[INFO] 
[INFO] 
[INFO] --- maven-jar-plugin:3.3.0:jar (default-jar) @ action-in-blog ---
[INFO] Building jar: /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/action-in-blog-0.0.1-SNAPSHOT.jar
[INFO] 
[INFO] --- spring-boot-maven-plugin:3.0.4:repackage (repackage) @ action-in-blog ---
[INFO] Replacing main artifact with repackaged archive
[INFO] 
[INFO] --- jacoco-maven-plugin:0.8.8:report (jacoco-report) @ action-in-blog ---
[INFO] Loading execution data file /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/jacoco.exec
[INFO] Analyzed bundle 'action-in-blog' with 1 classes
[INFO] 
[INFO] --- jacoco-maven-plugin:0.8.8:check (jacoco-check) @ action-in-blog ---
[INFO] Loading execution data file /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/jacoco.exec
[INFO] Analyzed bundle 'action-in-blog' with 1 classes
[INFO] All coverage checks have been met.
[INFO] 
[INFO] --- maven-install-plugin:3.0.1:install (default-install) @ action-in-blog ---
[INFO] Installing /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/pom.xml to /Users/junhyunk/.m2/repository/action/in/blog/action-in-blog/0.0.1-SNAPSHOT/action-in-blog-0.0.1-SNAPSHOT.pom
[INFO] Installing /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/action-in-blog-0.0.1-SNAPSHOT.jar to /Users/junhyunk/.m2/repository/action/in/blog/action-in-blog/0.0.1-SNAPSHOT/action-in-blog-0.0.1-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  3.442 s
[INFO] Finished at: 2023-03-18T22:37:34+09:00
[INFO] ------------------------------------------------------------------------

Code Coverage Report

프로젝트 /target/site/jacoco 경로에 index.html 파일로 리포트가 생성된 것을 확인할 수 있습니다.

Result of Code Coverage

CLOSING

코드 커버리지에 대한 기준을 변경하거나 테스트를 일부 제거하면 빌드가 실패하는 것을 확인할 수 있습니다.

$ mvn clean install

[INFO] Scanning for projects...
[INFO] 
[INFO] -------------------< action.in.blog:action-in-blog >--------------------
[INFO] Building action-in-blog 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:3.2.0:clean (default-clean) @ action-in-blog ---
[INFO] Deleting /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target
[INFO] 
[INFO] --- jacoco-maven-plugin:0.8.8:prepare-agent (jacoco-prepare-agent) @ action-in-blog ---
[INFO] argLine set to -javaagent:/Users/junhyunk/.m2/repository/org/jacoco/org.jacoco.agent/0.8.8/org.jacoco.agent-0.8.8-runtime.jar=destfile=/Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/jacoco.exec,excludes=**/action/in/blog/*Application.class
[INFO] 
[INFO] --- maven-resources-plugin:3.2.0:resources (default-resources) @ action-in-blog ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO] 
[INFO] --- maven-compiler-plugin:3.10.1:compile (default-compile) @ action-in-blog ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 2 source files to /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/classes
[INFO] 
[INFO] --- maven-resources-plugin:3.2.0:testResources (default-testResources) @ action-in-blog ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Using 'UTF-8' encoding to copy filtered properties files.
[INFO] skip non existing resourceDirectory /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/src/test/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.10.1:testCompile (default-testCompile) @ action-in-blog ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/test-classes
[INFO] 
[INFO] --- maven-surefire-plugin:2.22.2:test (default-test) @ action-in-blog ---
[INFO] 
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running action.in.blog.util.CalculatorTests
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.031 s - in action.in.blog.util.CalculatorTests
[INFO] 
[INFO] Results:
[INFO] 
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO] 
[INFO] 
[INFO] --- maven-jar-plugin:3.2.2:jar (default-jar) @ action-in-blog ---
[INFO] Building jar: /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/action-in-blog-0.0.1-SNAPSHOT.jar
[INFO] 
[INFO] --- spring-boot-maven-plugin:2.7.8:repackage (repackage) @ action-in-blog ---
[INFO] Replacing main artifact with repackaged archive
[INFO] 
[INFO] --- jacoco-maven-plugin:0.8.8:report (jacoco-report) @ action-in-blog ---
[INFO] Loading execution data file /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/jacoco.exec
[INFO] Analyzed bundle 'action-in-blog' with 1 classes
[INFO] 
[INFO] --- jacoco-maven-plugin:0.8.8:check (jacoco-check) @ action-in-blog ---
[INFO] Loading execution data file /Users/junhyunk/Desktop/workspace/blog/blog-in-action/2021-05-03-maven-jacoco/action-in-blog/target/jacoco.exec
[INFO] Analyzed bundle 'action-in-blog' with 1 classes
[WARNING] Rule violated for bundle action-in-blog: instructions covered ratio is 0.52, but expected minimum is 0.80
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  3.801 s
[INFO] Finished at: 2023-03-18T23:13:34+09:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.jacoco:jacoco-maven-plugin:0.8.8:check (jacoco-check) on project action-in-blog: Coverage checks have not been met. See log for details. -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

TEST CODE REPOSITORY

https://github.com/Junhyunny/blog-in-action/tree/master/2021-05-03-maven-jacoco

REFERENCE

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강준현

JaCoCo Maven Plugin

1. JaCoCo(Java Code Coverage)

2. Maven Plugin JaCoCo

2.1. pom.xml

2.2. Exclude Code

2.3. Goals

2.4. Rules

Example of Rules

3. Practice

3.1. System Under Test and Test Codes

3.1.1. Calculator Class

3.1.2. CalculatorTests Class

3.2. Run Maven Phase

Run Install Phase

Code Coverage Report

Result of Code Coverage

CLOSING

TEST CODE REPOSITORY

REFERENCE

공유하기

댓글남기기

참고

Memory leak by detached DOM elements in React

Mark-and-sweep algorithm for garbage collect

Reference counting algorithm for garbage collect

Socket Identificaiton

강준현

RECOMMEND POSTS BEFORE THIS

1. JaCoCo(Java Code Coverage)

2. Maven Plugin JaCoCo

2.1. pom.xml

2.2. Exclude Code

2.3. Goals

2.4. Rules

Example of Rules

3. Practice

3.1. System Under Test and Test Codes

3.1.1. Calculator Class

3.1.2. CalculatorTests Class

3.2. Run Maven Phase

Run Install Phase

Code Coverage Report

Result of Code Coverage

CLOSING

TEST CODE REPOSITORY

REFERENCE

공유하기

댓글남기기

참고

Memory leak by detached DOM elements in React

Mark-and-sweep algorithm for garbage collect

Reference counting algorithm for garbage collect

Socket Identificaiton