test: add jacoco

build.gradle

@@ -1,5 +1,6 @@
 allprojects {
     apply(plugin: 'java')
+    apply(plugin: 'jacoco')
 
     repositories {
         mavenCentral()
@@ -11,6 +12,13 @@ allprojects {
         }
     }
 
+    test {
+        finalizedBy jacocoTestReport // report is always generated after tests run
+    }
+    jacocoTestReport {
+        dependsOn test // tests are required to run before generating the report
+    }
+
     dependencies {
         testImplementation platform('org.junit:junit-bom:5.11.3')
         testImplementation 'org.junit.jupiter:junit-jupiter'