Android项目集成Jacoco后无法生成代码覆盖率报告

核心排查点与修复方案 #

1. 确认自定义Jacoco任务已手动执行 #

你的配置注册了Jacoco{VariantName}CodeCoverage格式的自定义任务（比如JacocoDebugCodeCoverage），Android Studio不会自动执行该任务，必须手动触发：

• 打开右侧边栏的Gradle面板
• 找到项目 → Tasks → Reporting → 双击对应变体的Jacoco任务（如JacocoDebugCodeCoverage）执行

2. 适配AGP 7+的编译类目录路径 #

你的classDirectories配置路径在AGP 7及以上版本失效，编译后Java/Kotlin类的目录结构已变更：

• Java类目录需指定具体变体（如debug）：intermediates/javac/{variantName}
• Kotlin类目录从tmp/kotlin-classes/改为intermediates/kotlin-classes/{variantName}

修正后的classDirectories配置：

classDirectories.setFrom(files(
        fileTree(dir: layout.buildDirectory.dir("intermediates/javac/${variantName}")) {
            exclude "**/R.class", "**/R\$*.class", "**/BuildConfig.*", "**/Manifest*.*", "**/*Test*.*"
        },
        fileTree(dir: layout.buildDirectory.dir("intermediates/kotlin-classes/${variantName}")) {
            exclude "**/R.class", "**/R\$*.class", "**/BuildConfig.*", "**/Manifest*.*", "**/*Test*.*"
        }
))

3. 精准定位测试执行数据文件 #

过宽的文件匹配可能读取无效数据，建议直接指定单元测试和UI测试的执行文件路径：

executionData.setFrom(files(
        // 单元测试执行数据
        layout.buildDirectory.dir("outputs/unit_test_code_coverage/${variantName}UnitTest/test${variantName}UnitTest.exec"),
        // UI测试执行数据
        layout.buildDirectory.dir("outputs/code_coverage/${variantName}AndroidTest/connected/*coverage.ec")
))

4. 移除已弃用的配置项 #

AGP 4.1+中enableAndroidTestCoverage和enableUnitTestCoverage已被弃用，仅保留testCoverageEnabled即可：

debug {
    testCoverageEnabled = true
}

5. 验证测试任务执行状态 #

如果单元测试或UI测试执行失败，Jacoco无法生成有效执行数据：

• 先单独运行testDebugUnitTest和connectedDebugAndroidTest任务，确认所有测试通过
• 检查测试控制台输出，排除测试报错、设备连接失败等问题

修正后的完整配置示例 #

apply plugin: 'jacoco'

android {
    buildTypes {
        debug {
            testCoverageEnabled = true
        }
    }

    applicationVariants.configureEach { variant ->
        def variantName = variant.name.capitalize()
        def unitTests = "test${variantName}UnitTest"
        def androidTests = "connected${variantName}AndroidTest"

        tasks.register("Jacoco${variantName}CodeCoverage", JacocoReport) {
            dependsOn(unitTests, androidTests)
            group = "Reporting"
            description = "执行UI和单元测试，生成并合并Jacoco覆盖率报告"

            reports {
                xml.required = true
                xml.outputLocation = layout.buildDirectory.file("jacoco/xml/${variantName}Coverage.xml")
                html.required = true
                html.outputLocation = layout.buildDirectory.dir("jacoco/html/${variantName}Coverage.html")
            }

            sourceDirectories.setFrom(layout.projectDirectory.dir("src/main"))

            classDirectories.setFrom(files(
                    fileTree(dir: layout.buildDirectory.dir("intermediates/javac/${variantName}")) {
                        exclude "**/R.class", "**/R\$*.class", "**/BuildConfig.*", "**/Manifest*.*", "**/*Test*.*"
                    },
                    fileTree(dir: layout.buildDirectory.dir("intermediates/kotlin-classes/${variantName}")) {
                        exclude "**/R.class", "**/R\$*.class", "**/BuildConfig.*", "**/Manifest*.*", "**/*Test*.*"
                    }
            ))

            executionData.setFrom(files(
                    layout.buildDirectory.dir("outputs/unit_test_code_coverage/${variantName}UnitTest/test${variantName}UnitTest.exec"),
                    layout.buildDirectory.dir("outputs/code_coverage/${variantName}AndroidTest/connected/*coverage.ec")
            ))
        }
    }
}

jacoco {
    toolVersion = "0.8.8"
}

tasks.withType(Test).configureEach {
    jacoco {
        excludes = [
                "**/R.class",
                "**/R\$*.class",
                "**/BuildConfig.*",
                "**/Manifest*.*",
                "**/*Test*.*"
        ]
    }
}

执行修正后的配置后，重新运行对应变体的Jacoco任务，报告会生成在build/jacoco/html/{VariantName}Coverage.html路径下，直接打开该HTML文件即可查看覆盖率详情。

内容的提问来源于stack exchange，提问作者kgsharathkumar