java-coverage

• Setting up code coverage reporting
• Configuring coverage thresholds
• Aggregating coverage across modules
• Integrating with SonarQube
• Troubleshooting coverage reports

Sections

• [When to use this skill](#when-to-use-this-skill) (L23-L30)
• [Quick Start](#quick-start) (L56-L93)
• [Coverage Thresholds](#coverage-thresholds) (L94-L118)
• [Exclusions](#exclusions) (L119-L138)
• [Multi-Module Aggregation](#multi-module-aggregation) (L139-L189)
• [SonarQube Integration](#sonarqube-integration) (L190-L200)
• [References](#references) (L201-L207)
• [Related Rules](#related-rules) (L208-L211)
• [Related Skills](#related-skills) (L212-L218)

Available Resources

📚 references/ - Detailed documentation

• [coverage targets](references/coverage-targets.md)
• [exclusion patterns](references/exclusion-patterns.md)
• [improvement workflow](references/improvement-workflow.md)
• [multi module](references/multi-module.md)
• [prioritization](references/prioritization.md)

---

1. Apply JaCoCo Plugin

```groovy

plugins {

id 'jacoco'

}

jacoco {

toolVersion = "0.8.14"

}

```

2. Configure Report Task

```groovy

jacocoTestReport {

dependsOn test

reports {

xml.required = true // For SonarQube

html.required = true // For local viewing

}

}

test {

finalizedBy jacocoTestReport

}

```

3. Run Coverage

```bash

./gradlew test jacocoTestReport

# Report at: build/reports/jacoco/test/html/index.html

```

```groovy

jacocoTestCoverageVerification {

violationRules {

rule {

limit {

minimum = 0.80 // 80% minimum coverage

}

}

rule {

element = 'CLASS'

excludes = ['.generated.', '.config.']

limit {

counter = 'LINE'

minimum = 0.70

}

}

}

}

check.dependsOn jacocoTestCoverageVerification

```

Common patterns to exclude from coverage:

```groovy

jacocoTestReport {

afterEvaluate {

classDirectories.setFrom(files(classDirectories.files.collect {

fileTree(dir: it, exclude: [

'/generated/',

'/config/',

'*/Config.class',

'*/Properties.class',

'**/Application.class'

])

}))

}

}

```

For aggregated reports across modules, use the modern jacoco-report-aggregation plugin (Gradle 7.4+):

```groovy

// In root build.gradle

plugins {

id 'base'

id 'jacoco-report-aggregation'

}

// Ensure subprojects are evaluated first

subprojects.each { evaluationDependsOn(it.path) }

dependencies {

subprojects.each { jacocoAggregation it }

}

reporting {

reports {

testCodeCoverageReport(JacocoCoverageReport) {

testType = TestSuiteType.UNIT_TEST

}

}

}

```

For older Gradle versions, use a manual task with defensive filtering:

```groovy

// In root build.gradle (Gradle < 7.4)

task jacocoRootReport(type: JacocoReport) {

dependsOn subprojects*.test

// Use defensive filtering to avoid missing-directory errors

def srcDirs = files(subprojects.sourceSets.main.allSource.srcDirs).filter { it.exists() }

def classDirs = files(subprojects.sourceSets.main*.output).filter { it.exists() }

def execData = files(subprojects.jacocoTestReport.executionData).filter { it.exists() }

additionalSourceDirs.from(srcDirs)

sourceDirectories.from(srcDirs)

classDirectories.from(classDirs)

executionData.from(execData)

reports {

xml.required = true

html.required = true

}

}

```

```groovy

sonar {

properties {

property 'sonar.coverage.jacoco.xmlReportPaths',

"${projectDir}/build/reports/jacoco/test/jacocoTestReport.xml"

}

}

```

| Reference | Description |

|-----------|-------------|

| [references/exclusion-patterns.md](references/exclusion-patterns.md) | Common exclusion patterns |

| [references/multi-module.md](references/multi-module.md) | Multi-module aggregation |

• .cursor/rules/java-jacoco-coverage.mdc - Full JaCoCo reference

| Skill | Purpose |

|-------|---------|

| [java-testing](../java-testing/SKILL.md) | Test configuration |

| [sonarqube-integration](../sonarqube-integration/SKILL.md) | SonarQube setup |

| [gradle-standards](../gradle-standards/SKILL.md) | Gradle configuration |