chore: improved build configuration

build.gradle

@@ -16,8 +16,8 @@ sourceSets {
     regressionTests {
         java {
             compileClasspath += main.output + test.output
-            runtimeClasspath += main.output + files('src/main/java') 
-            java.srcDir file('src/r_tests/java')
+            runtimeClasspath += main.output + test.output + files('src/main/java') 
+            srcDir file('src/r_tests/java')
         }
     }
 }
@@ -26,12 +26,13 @@ configurations{
     regressionTestsCompile.extendsFrom mainCompile
     regressionTestsRuntime.extendsFrom mainRuntime
     regressionTestsRuntime.extendsFrom compileClasspath
+    regressionTestsImplementation.extendsFrom compileClasspath
 }
 dependencies{
     regressionTestsImplementation group: 'commons-io', name: 'commons-io', version: '2.8.0'
     regressionTestsImplementation group: 'org.junit.jupiter', name: 'junit-jupiter-api', version: '5.7.1'
     regressionTestsImplementation group: 'org.junit.jupiter', name: 'junit-jupiter-engine', version: '5.7.1'
-    regressionTestsRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
+    regressionTestsImplementation 'org.junit.jupiter:junit-jupiter-engine'
 
     compileClasspath 'org.libreoffice:jurt:5.3.2'
     compileClasspath 'org.libreoffice:juh:5.3.2'