Issue 4181 - Fix FilterEngineTest tests

libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/BaseJsTest.java

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 package org.adblockplus.libadblockplus.tests;
 
 import org.adblockplus.libadblockplus.AppInfo;
+import org.adblockplus.libadblockplus.FileSystemUtils;
 import org.adblockplus.libadblockplus.JsEngine;
-import org.adblockplus.libadblockplus.LazyLogSystem;
 import org.adblockplus.libadblockplus.ThrowingWebRequest;
 
 import android.content.Context;
 import android.test.InstrumentationTestCase;
 
+import java.io.File;
+
 public abstract class BaseJsTest extends InstrumentationTestCase
 {
   protected JsEngine jsEngine;
+  protected File tmpFileSystemPath;
+
+  protected File buildTmpFileSystemPath()
+  {
+    File tmpFileSystemPath = FileSystemUtils.generateUniqueFile(null, ".fs", getContext().getCacheDir());
+    tmpFileSystemPath.mkdirs();
+    return tmpFileSystemPath;
+  }
 
   @Override
   protected void setUp() throws Exception
   {
     super.setUp();
 
     jsEngine = new JsEngine(AppInfo.builder().build());
     jsEngine.setDefaultLogSystem();
-    jsEngine.setDefaultFileSystem(getContext().getFilesDir().getAbsolutePath());
+
+    // we need to generate new file system path in order
+    // not to have JsEngine state from the previous test
+    tmpFileSystemPath = buildTmpFileSystemPath();
+    jsEngine.setDefaultFileSystem(tmpFileSystemPath.getAbsolutePath());
     jsEngine.setWebRequest(new ThrowingWebRequest());
   }
 
+  protected void cleanupFileSystem()
+  {
+    if (tmpFileSystemPath != null && tmpFileSystemPath.exists())
+    {
+      FileSystemUtils.delete(tmpFileSystemPath);
+      tmpFileSystemPath = null;
+    }
+  }
+
+  @Override
+  protected void tearDown() throws Exception
+  {
+    cleanupFileSystem();
+    super.tearDown();
+  }
+
   protected Context getContext()
   {
     return getInstrumentation().getTargetContext();
   }
 }