Removed javac bash commands to compile test cases

Earlier we are using the java commands to compile and run test cases, Now we are using gradle for building and running test cases.

Author: MohitMaliFtechiz

lib/build.gradle

@@ -67,13 +67,6 @@ android {
         viewBinding true
     }
     ndkVersion '21.4.7075529'
-
-    configurations {
-        testCompileClasspath.extendsFrom(compileClasspath)
-        testRuntimeClasspath.extendsFrom(testCompileClasspath)
-        testImplementation.extendsFrom(implementation)
-        testRuntimeOnly.extendsFrom(runtimeOnly)
-    }
 }
 
 dependencies {
@@ -276,21 +269,40 @@ task renameLibkiwixSoFile(type: Copy) {
     }
 }
 
-task compileTestFile(type: Exec) {
-    workingDir "${projectDir}/src/test/"
-    commandLine 'javac', '-g', '-d', '.', '-s', '.', '-cp', 'junit-4.13.jar:' + buildDir.path +'/libs/*', 'test.java'
+task testSourceJar(type: Jar) {
+    from android.sourceSets.test.java.srcDirs
+    archiveName = 'test-sources.jar'
 }
 
-task runTests(type: Exec) {
-    workingDir "${projectDir}/src/test/"
+task compileTestFile(type: JavaCompile) {
+    dependsOn testSourceJar
+    source = fileTree('src/test/')
+    destinationDirectory = file('src/test/')
+    classpath = files("src/test/junit-4.13.jar" , "src/test/hamcrest-core-1.4.jar", "build/libs/test-sources.jar")
+}
+
+task runTests(type: JavaExec) {
+    workingDir("$projectDir/src/test/")
     dependsOn compileTestFile
-    commandLine 'java', '-Djava.library.path=' + buildDir.path, '-javaagent:jacoco-0.8.7/lib/jacocoagent.jar', '-cp', 'junit-4.13.jar:hamcrest-core-1.3.jar:' + buildDir.path +'/libs/*lib*.jar' + ':.', 'org.junit.runner.JUnitCore', 'test'
+    classpath = files('src/test/', 'src/test/java/', 'src/test/junit-4.13.jar', 'src/test/hamcrest-core-1.3.jar')
+    main = 'org.junit.runner.JUnitCore'
+    args = ['test']
+    jvmArgs = [
+            '-Djava.library.path=' + buildDir.path,
+            '-javaagent:jacoco-0.8.7/lib/jacocoagent.jar'
+    ]
 }
 
-task createCodeCoverageReport(type: Exec) {
+task createCodeCoverageReport(type: JavaExec) {
     workingDir "${projectDir}/src/test/"
     dependsOn runTests
-    commandLine 'java', '-jar', 'jacoco-0.8.7/lib/jacococli.jar', 'report', 'jacoco.exec', '--classfiles', 'org/kiwix/libkiwix/', '--classfiles', 'org/kiwix/libzim/', '--html', '../../build/coverage-report', '--xml', 'coverage.xml'
+    classpath = files('src/test/', 'src/test/java/', 'src/test/junit-4.13.jar', 'src/test/hamcrest-core-1.3.jar', 'src/test/jacoco-0.8.7/lib/*')
+    main = 'org.jacoco.cli.internal.Main'
+    args = [
+            'report', 'jacoco.exec',
+            '--classfiles', 'java/org/kiwix/libkiwix/', '--classfiles', 'java/org/kiwix/libzim/',
+            '--html', '../../build/coverage-report', '--xml', 'coverage.xml'
+    ]
 }
 
 task checkCurrentJavaVersion() {
@@ -300,9 +312,9 @@ task checkCurrentJavaVersion() {
 }
 
 
-task buildHeaders(type: Exec) {
+task generateHeader(type: Exec) {
     workingDir "${projectDir}/src/main/java/org/kiwix/"
-    commandLine 'bash', '-c', "javac -h ${buildDir}/include/javah_generated/ -d ${projectDir}/src/test/ ${getLibzimFiles()} ${getLibkiwixFiles()}"
+    commandLine 'bash', '-c', "javac -h ${buildDir}/include/javah_generated/ -d ${projectDir}/src/test/java/ ${getLibzimFiles()} ${getLibkiwixFiles()}"
 }
 
 String getLibkiwixFiles() {