Issue 4231 - Fix unstable FilterEngineTest.testSetRemoveFilterChangeCallback

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

Index: libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java
diff --git a/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java b/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java
index 92a098f916017356fff71803647749eab2eefed4..242e1a94ab958405663a7a2aa9f61d125ce1ae4b 100644
--- a/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java
+++ b/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/FilterEngineGenericTest.java
@@ -17,6 +17,7 @@
 
 package org.adblockplus.libadblockplus.tests;
 
+import org.adblockplus.libadblockplus.FileSystem;
 import org.adblockplus.libadblockplus.FilterEngine;
 import org.adblockplus.libadblockplus.LazyWebRequest;
 
@@ -24,6 +25,74 @@ public abstract class FilterEngineGenericTest extends BaseJsTest
 {
   protected FilterEngine filterEngine;
 
+  private static final class PatternsIniStubFileSystem extends FileSystem
+  {
+    private static final String PATTERNS_INI = "patterns.ini";
+
+    private boolean patternsIniExists = true;
+
+    public boolean isPatternsIniExists()
+    {
+      return patternsIniExists;
+    }
+
+    public void setPatternsIniExists(boolean patternsIniExists)
+    {
+      this.patternsIniExists = patternsIniExists;
+    }
+
+    @Override
+    public byte[] read(String path)
+    {
+      String result;
+      if (path.equals(PATTERNS_INI))
+      {
+        result = "# Adblock Plus preferences\n[Subscription]\nurl=~fl~";
+      }
+      else if (path.equals("prefs.json"))
+      {
+        result = "{}";
+      }
+      else
+      {
+        result = "";
+      }
+      return result.getBytes();
+    }
+
+    @Override
+    public void write(String path, byte[] data)
+    {
+
+    }
+
+    @Override
+    public void move(String fromPath, String toPath)
+    {
+
+    }
+
+    @Override
+    public void remove(String path)
+    {
+
+    }
+
+    @Override
+    public FileSystem.StatResult stat(String path)
+    {
+      return path.equals(PATTERNS_INI)
+        ? new FileSystem.StatResult(patternsIniExists, false, true, 0)
+        : new FileSystem.StatResult(false, false, false, 0);
+    }
+
+    @Override
+    public String resolve(String path)
+    {
+      return path;
+    }
+  }
+
   @Override
   protected void setUp() throws Exception
   {
@@ -31,6 +100,7 @@ public abstract class FilterEngineGenericTest extends BaseJsTest
 
     jsEngine.setWebRequest(new LazyWebRequest());
     jsEngine.setDefaultLogSystem();
+    jsEngine.setFileSystem(new PatternsIniStubFileSystem());
 
     filterEngine = new FilterEngine(jsEngine);
   }