Issue 4231 - Fix unstable FilterEngineTest.testSetRemoveFilterChangeCallback

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

Index: libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/LazyFileSystem.java
diff --git a/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/LazyFileSystem.java b/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/LazyFileSystem.java
new file mode 100644
index 0000000000000000000000000000000000000000..6c08cde725e9ad8a1c7fbf472901de566df1261b
--- /dev/null
+++ b/libadblockplus-android-tests/src/org/adblockplus/libadblockplus/tests/LazyFileSystem.java
@@ -0,0 +1,84 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2016 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.FileSystem;
+
+public class LazyFileSystem extends FileSystem
+{
+  private boolean patternsIniExists = true;
+
+  public boolean isPatternsIniExists()
+  {
+    return patternsIniExists;
+  }
+
+  public void setPatternsIniExists(boolean patternsIniExists)
+  {
+    this.patternsIniExists = patternsIniExists;
+  }
+
+  @Override
+  public String read(String path)
+  {
+    if (path.equals("patterns.ini"))
+    {
+      return "# Adblock Plus preferences\n[Subscription]\nurl=~fl~";
+    }
+    else if (path.equals("prefs.json"))
+    {
+      return "{}";
+    }
+    else
+    {
+      return "";
+    }
+  }
+
+  @Override
+  public void write(String path, String data)
+  {
+
+  }
+
+  @Override
+  public void move(String fromPath, String toPath)
+  {
+
+  }
+
+  @Override
+  public void remove(String path)
+  {
+
+  }
+
+  @Override
+  public StatResult stat(String path)
+  {
+    return path.equals("patterns.ini")
+      ? new StatResult(patternsIniExists, false, true, 0)
+      : new StatResult(false, false, false, 0);
+  }
+
+  @Override
+  public String resolve(String path)
+  {
+    return path;
+  }
+}