Also make default ObjectMapper for ToJsonFilter use snake_properties …

…if legacy override is set

src/main/java/com/hubspot/jinjava/JinjavaConfig.java

@@ -18,6 +18,7 @@
 import static com.hubspot.jinjava.lib.fn.Functions.DEFAULT_RANGE_LIMIT;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
 import com.hubspot.jinjava.el.JinjavaInterpreterResolver;
 import com.hubspot.jinjava.el.JinjavaNodePreProcessor;
 import com.hubspot.jinjava.el.JinjavaObjectUnwrapper;
@@ -44,6 +45,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.function.BiConsumer;
+import javax.annotation.Nullable;
 import javax.el.ELResolver;
 
 public class JinjavaConfig {
@@ -135,11 +137,21 @@ private JinjavaConfig(Builder builder) {
     legacyOverrides = builder.legacyOverrides;
     dateTimeProvider = builder.dateTimeProvider;
     enablePreciseDivideFilter = builder.enablePreciseDivideFilter;
-    objectMapper = builder.objectMapper;
+    objectMapper = setupObjectMapper(builder.objectMapper);
     objectUnwrapper = builder.objectUnwrapper;
     nodePreProcessor = builder.nodePreProcessor;
   }
 
+  private ObjectMapper setupObjectMapper(@Nullable ObjectMapper objectMapper) {
+    if (objectMapper == null) {
+      objectMapper = new ObjectMapper();
+      if (legacyOverrides.isUseSnakeCasePropertyNaming()) {
+        objectMapper.setPropertyNamingStrategy(PropertyNamingStrategies.SNAKE_CASE);
+      }
+    }
+    return objectMapper;
+  }
+
   public Charset getCharset() {
     return charset;
   }
@@ -298,7 +310,7 @@ public static class Builder {
     private ExecutionMode executionMode = DefaultExecutionMode.instance();
     private LegacyOverrides legacyOverrides = LegacyOverrides.NONE;
     private boolean enablePreciseDivideFilter = false;
-    private ObjectMapper objectMapper = new ObjectMapper();
+    private ObjectMapper objectMapper = null;
 
     private ObjectUnwrapper objectUnwrapper = new JinjavaObjectUnwrapper();
     private BiConsumer<Node, JinjavaInterpreter> nodePreProcessor = new JinjavaNodePreProcessor();

src/main/java/com/hubspot/jinjava/lib/filter/FromJsonFilter.java

@@ -1,6 +1,5 @@
 package com.hubspot.jinjava.lib.filter;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
 import com.hubspot.jinjava.doc.annotations.JinjavaDoc;
 import com.hubspot.jinjava.doc.annotations.JinjavaParam;
 import com.hubspot.jinjava.doc.annotations.JinjavaSnippet;
@@ -19,7 +18,6 @@
   snippets = { @JinjavaSnippet(code = "{{object|fromJson}}") }
 )
 public class FromJsonFilter implements Filter {
-  private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
   @Override
   public Object filter(Object var, JinjavaInterpreter interpreter, String... args) {
@@ -31,7 +29,10 @@ public Object filter(Object var, JinjavaInterpreter interpreter, String... args)
       throw new InvalidInputException(interpreter, this, InvalidReason.STRING);
     }
     try {
-      return OBJECT_MAPPER.readValue((String) var, Object.class);
+      return interpreter
+        .getConfig()
+        .getObjectMapper()
+        .readValue((String) var, Object.class);
     } catch (IOException e) {
       throw new InvalidInputException(interpreter, this, InvalidReason.JSON_READ);
     }