1 files changed, 23 insertions, 1 deletions
diff --git a/app/src/main/java/se/leap/bitmaskclient/base/utils/InputStreamHelper.java b/app/src/main/java/se/leap/bitmaskclient/base/utils/InputStreamHelper.java
index 8e6273a7..6dfe0861 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/utils/InputStreamHelper.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/utils/InputStreamHelper.java
@@ -8,14 +8,36 @@ import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 
+import de.blinkt.openvpn.core.NativeUtils;
+
 /**
  * Created by cyberta on 18.03.18.
  */
 
 public class InputStreamHelper {
+    public interface InputStreamHelperInterface {
+        InputStream getInputStreamFrom(String filePath) throws FileNotFoundException;
+
+    }
+
+    private static InputStreamHelperInterface instance = new DefaultInputStreamHelper();
+
+    private static class DefaultInputStreamHelper implements InputStreamHelperInterface {
+        @Override
+        public InputStream getInputStreamFrom(String filePath) throws FileNotFoundException {
+            return new FileInputStream(filePath);
+        }
+    }
+
+    public InputStreamHelper(InputStreamHelperInterface helperInterface) {
+        if (!NativeUtils.isUnitTest()) {
+            throw new IllegalStateException("InputStreamHelper injected with InputStreamHelperInterface outside of an unit test");
+        }
+        instance = helperInterface;
+    }
     //allows us to mock FileInputStream
     public static InputStream getInputStreamFrom(String filePath) throws FileNotFoundException {
-        return new FileInputStream(filePath);
+        return instance.getInputStreamFrom(filePath);
     }
 
     public static String loadInputStreamAsString(InputStream is) {