Make jacoco/coveralls aggregate reports.

build.gradle

@@ -4,8 +4,8 @@ subprojects {
     apply plugin: 'com.dmdirc.git-version'
     apply plugin: 'maven-publish'
     apply plugin: 'java'
-    apply plugin: 'jacoco'
-    apply plugin: 'com.github.kt3k.coveralls'
+
+    apply from: '../gradle/coverage.gradle'
 
     sourceSets {
         main.java.srcDirs = ['src']
@@ -106,13 +106,6 @@ subprojects {
     artifacts {
         archives javadocJar, sourcesJar
     }
-
-    jacocoTestReport {
-        reports {
-            xml.enabled = true // coveralls plugin depends on xml format report
-            html.enabled = true
-        }
-    }
 }
 
 task wrapper(type: Wrapper) {
@@ -142,3 +135,6 @@ buildscript {
         classpath 'org.kt3k.gradle.plugin:coveralls-gradle-plugin:2.1.0'
     }
 }
+
+apply from: 'gradle/coverage.gradle'
+

circle.yml

@@ -14,4 +14,4 @@ test:
   override:
     - ./gradlew check
   post:
-    - ./gradlew jacocoTestReport coveralls
+    - ./gradlew coveralls

gradle/coverage.gradle

@@ -0,0 +1,34 @@
+apply plugin: 'jacoco'
+apply plugin: 'com.github.kt3k.coveralls'
+
+task jacocoRootReport(type: JacocoReport, group: 'Coverage reports', dependsOn: subprojects.test) {
+  description = 'Generates an aggregate report from all subprojects'
+
+  additionalSourceDirs = files(subprojects.sourceSets.main.allSource.srcDirs)
+  sourceDirectories = files(subprojects.sourceSets.main.allSource.srcDirs)
+  classDirectories = files(subprojects.sourceSets.main.output)
+  executionData = files(subprojects.jacocoTestReport.executionData)
+
+  reports {
+    html.enabled = true
+    xml.enabled = true
+  }
+
+  doFirst {
+    executionData = files(executionData.findAll { it.exists() })
+  }
+}
+
+coveralls {
+  jacocoReportPath = "${buildDir}/reports/jacoco/jacocoRootReport/jacocoRootReport.xml"
+  subprojects.sourceSets.main.allSource.srcDirs*.path.each { sourceDirs.addAll(it) }
+}
+
+tasks.coveralls {
+  group = 'Coverage reports'
+  description = 'Uploads the aggregated coverage report to Coveralls'
+
+  dependsOn jacocoRootReport
+  onlyIf { System.env.'CI' }
+}
+