diff --git a/frontend/src/features/overrides/editor/CodeEditor.tsx b/frontend/src/features/overrides/editor/CodeEditor.tsx
index e9ac054..e2db479 100644
--- a/frontend/src/features/overrides/editor/CodeEditor.tsx
+++ b/frontend/src/features/overrides/editor/CodeEditor.tsx
@@ -29,7 +29,7 @@ export default function CodeEditor() {
         color="inherit"
         aria-label="save"
         onClick={
-          ()=>selectedEdge && updateOverride({injectionPoint: selectedEdge, transformationJs: currentTxJs})
+          ()=>selectedEdge && updateOverride({injectionPoint: selectedEdge, transformationJs: currentTxJs || '(request)=>(request)'})
         .then(() => {
           dispatch(setTransformationJs(undefined));
           dispatch(openAlert(`Save success. Transformation will be applied to ${selectedEdge}.`));
diff --git a/src/test/scala/ai/diffy/functional/algebra/BijectionTest.java b/src/test/scala/ai/diffy/functional/algebra/BijectionTest.java
new file mode 100644
index 0000000..e8275ba
--- /dev/null
+++ b/src/test/scala/ai/diffy/functional/algebra/BijectionTest.java
@@ -0,0 +1,15 @@
+package ai.diffy.functional.algebra;
+
+public class BijectionTest {
+    public static void main(String[] args) {
+        Bijection<String, String> identity = Bijection.of(String::toUpperCase, String::toLowerCase);
+        try {
+            identity.apply("s");
+            identity.unapply("s");
+            String x = identity.wrap(str -> str+str).apply("lower");
+            System.out.println(x);
+        } catch (Throwable e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/test/scala/ai/diffy/interpreter/SimpleTransformerTest.java b/src/test/scala/ai/diffy/interpreter/SimpleTransformerTest.java
new file mode 100644
index 0000000..7914d93
--- /dev/null
+++ b/src/test/scala/ai/diffy/interpreter/SimpleTransformerTest.java
@@ -0,0 +1,19 @@
+package ai.diffy.interpreter;
+
+public class SimpleTransformerTest {
+    public static class Name{
+        public String first;
+        public String last;
+    }
+    public static void main(String[] args) {
+        try {
+            Name name = new Name();
+            name.first = "Puneet";
+            name.last = "Khanduri";
+            Transformer<Name> transformer = new Transformer<>(Name.class, "(name)=>{console.log(JSON.stringify(name,null,4)); return name;}");
+            transformer.apply(name);
+        } catch (Throwable e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
diff --git a/src/test/scala/ai/diffy/interpreter/TxTest.java b/src/test/scala/ai/diffy/interpreter/TransformerTest.java
similarity index 94%
rename from src/test/scala/ai/diffy/interpreter/TxTest.java
rename to src/test/scala/ai/diffy/interpreter/TransformerTest.java
index e48095e..8d0321c 100644
--- a/src/test/scala/ai/diffy/interpreter/TxTest.java
+++ b/src/test/scala/ai/diffy/interpreter/TransformerTest.java
@@ -9,7 +9,7 @@
 import java.util.HashMap;
 import java.util.Map;
 
-public class TxTest {
+public class TransformerTest {
     public static void main(String [] args) {
         try {
             Source tx = Source.newBuilder("js", new File("src/test/scala/ai/diffy/interpreter/transform.js")).build();
@@ -22,7 +22,7 @@ public static void main(String [] args) {
             System.out.println("All done!");
             System.out.println("\n\nHere's the original:\n"+request);
             System.out.println("\n\nHere's the transformed:\n"+transformed);
-        } catch (Exception e) {
+        } catch (Throwable e) {
             throw new RuntimeException(e);
         }
     }
diff --git a/src/test/scala/ai/diffy/proxy/ReactorHttpDifferenceProxyTest.java b/src/test/scala/ai/diffy/proxy/ReactorHttpDifferenceProxyTest.java
new file mode 100644
index 0000000..8ba5548
--- /dev/null
+++ b/src/test/scala/ai/diffy/proxy/ReactorHttpDifferenceProxyTest.java
@@ -0,0 +1,14 @@
+package ai.diffy.proxy;
+
+import reactor.core.publisher.Mono;
+
+import java.util.concurrent.CompletableFuture;
+
+public class ReactorHttpDifferenceProxyTest {
+    public static void main(String[] args) {
+        Mono.fromFuture(CompletableFuture.failedFuture(new RuntimeException()))
+                .doOnError(t -> System.out.println("error"))
+                .block()
+        ;
+    }
+}