Debug Undefined Feature to echo back Uknown tokens.

abarrafo · abarrafo · commit 51b9f6f3588c · 2024-01-19T12:48:37.000-05:00
diff --git a/src/main/java/com/hubspot/jinjava/lib/expression/DefaultExpressionStrategy.java b/src/main/java/com/hubspot/jinjava/lib/expression/DefaultExpressionStrategy.java
@@ -1,5 +1,6 @@
 package com.hubspot.jinjava.lib.expression;
 
+import com.hubspot.jinjava.features.FeatureActivationStrategy;
 import com.hubspot.jinjava.interpret.JinjavaInterpreter;
 import com.hubspot.jinjava.lib.filter.EscapeFilter;
 import com.hubspot.jinjava.objects.SafeString;
@@ -11,6 +12,7 @@
 public class DefaultExpressionStrategy implements ExpressionStrategy {
 
   private static final long serialVersionUID = 436239440273704843L;
+  public static final String ECHO_UNDEFINED = "echoUndefined";
 
   public RenderedOutputNode interpretOutput(
     ExpressionToken master,
@@ -41,6 +43,14 @@ public RenderedOutputNode interpretOutput(
     if (interpreter.getContext().isAutoEscape() && !(var instanceof SafeString)) {
       result = EscapeFilter.escapeHtmlEntities(result);
     }
+    final FeatureActivationStrategy feat = interpreter
+          .getConfig()
+          .getFeatures()
+          .getActivationStrategy(ECHO_UNDEFINED);
+
+  if (result.isEmpty() && feat.isActive(interpreter.getContext())){
+      result = master.getImage();
+  }
 
     return new RenderedOutputNode(result);
   }
diff --git a/src/test/java/com/hubspot/jinjava/tree/ExpressionNodeTest.java b/src/test/java/com/hubspot/jinjava/tree/ExpressionNodeTest.java
@@ -1,12 +1,15 @@
 package com.hubspot.jinjava.tree;
 
+import static com.hubspot.jinjava.lib.expression.DefaultExpressionStrategy.ECHO_UNDEFINED;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 import com.google.common.io.Resources;
 import com.hubspot.jinjava.BaseInterpretingTest;
 import com.hubspot.jinjava.Jinjava;
 import com.hubspot.jinjava.JinjavaConfig;
+import com.hubspot.jinjava.features.FeatureConfig;
+import com.hubspot.jinjava.features.FeatureStrategies;
 import com.hubspot.jinjava.interpret.Context;
 import com.hubspot.jinjava.interpret.JinjavaInterpreter;
 import com.hubspot.jinjava.interpret.UnknownTokenException;
@@ -129,6 +132,27 @@ public void itRendersStringRange() throws Exception {
     assertThat(node.render(interpreter).toString()).isEqualTo("345");
   }
 
+  @Test
+  public void itRenderDebugUndefined() {
+
+    final JinjavaConfig config = JinjavaConfig
+            .newBuilder()
+            .withFeatureConfig(FeatureConfig
+                    .newBuilder()
+                    .add(ECHO_UNDEFINED, FeatureStrategies.ACTIVE).build())
+            .build();
+    final JinjavaInterpreter jinjavaInterpreter = new Jinjava(config).newInterpreter();
+    jinjavaInterpreter.getContext().put("subject", "this");
+
+    String template = "{{ subject | capitalize() }} expression {{ testing.template('hello_world') }} " +
+            "has a {{ unknown | lower() }} " +
+            "token but {{ unknown | default(\"replaced\") }}";
+    Node node = new TreeParser(jinjavaInterpreter, template).buildTree();
+    assertThat(jinjavaInterpreter.render(node))
+            .isEqualTo("This expression {{ testing.template('hello_world') }} " +
+                    "has a {{ unknown | lower() }} token but replaced");
+  }
+
   @Test
   public void itFailsOnUnknownTokensVariables() throws Exception {
     final JinjavaConfig config = JinjavaConfig
