Add new MapELResolver with type coercion to support accessing enum keys

src/main/java/com/hubspot/jinjava/el/JinjavaInterpreterResolver.java

@@ -45,7 +45,6 @@
 import javax.el.CompositeELResolver;
 import javax.el.ELContext;
 import javax.el.ELResolver;
-import javax.el.MapELResolver;
 import javax.el.PropertyNotFoundException;
 import javax.el.ResourceBundleELResolver;
 import org.apache.commons.lang3.LocaleUtils;
@@ -57,7 +56,7 @@ public class JinjavaInterpreterResolver extends SimpleResolver {
     {
       add(new ArrayELResolver(true));
       add(new JinjavaListELResolver(true));
-      add(new MapELResolver(true));
+      add(new TypeConvertingMapELResolver(true));
       add(new ResourceBundleELResolver());
       add(new JinjavaBeanELResolver(true));
     }
@@ -68,7 +67,7 @@ public class JinjavaInterpreterResolver extends SimpleResolver {
     {
       add(new ArrayELResolver(false));
       add(new JinjavaListELResolver(false));
-      add(new MapELResolver(false));
+      add(new TypeConvertingMapELResolver(false));
       add(new ResourceBundleELResolver());
       add(new JinjavaBeanELResolver(false));
     }

src/main/java/com/hubspot/jinjava/el/TypeConvertingMapELResolver.java

@@ -0,0 +1,36 @@
+package com.hubspot.jinjava.el;
+
+import com.hubspot.jinjava.el.ext.CollectionMembershipOperator;
+import java.util.Map;
+import javax.el.ELContext;
+import javax.el.MapELResolver;
+
+public class TypeConvertingMapELResolver extends MapELResolver {
+  private static final TruthyTypeConverter TYPE_CONVERTER = new TruthyTypeConverter();
+
+  public TypeConvertingMapELResolver(boolean readOnly) {
+    super(readOnly);
+  }
+
+  @Override
+  public Object getValue(ELContext context, Object base, Object property) {
+    Object value = super.getValue(context, base, property);
+
+    if (value != null) {
+      return value;
+    }
+
+    if (
+      base instanceof Map &&
+      (Boolean) CollectionMembershipOperator.OP.apply(TYPE_CONVERTER, property, base)
+    ) {
+      Class<?> keyClass = ((Map) base).keySet().iterator().next().getClass();
+      value = ((Map) base).get(TYPE_CONVERTER.convert(property, keyClass));
+      if (value != null) {
+        context.setPropertyResolved(true);
+      }
+    }
+
+    return value;
+  }
+}

src/test/java/com/hubspot/jinjava/el/ext/AstDictTest.java

@@ -0,0 +1,53 @@
+package com.hubspot.jinjava.el.ext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.google.common.collect.ImmutableMap;
+import com.hubspot.jinjava.Jinjava;
+import com.hubspot.jinjava.interpret.JinjavaInterpreter;
+import com.hubspot.jinjava.interpret.TemplateError.ErrorType;
+import java.util.Map;
+import org.junit.Before;
+import org.junit.Test;
+
+public class AstDictTest {
+  private JinjavaInterpreter interpreter;
+
+  @Before
+  public void setup() {
+    interpreter = new Jinjava().newInterpreter();
+  }
+
+  @Test
+  public void itGetsDictValues() {
+    interpreter.getContext().put("foo", ImmutableMap.of("bar", "test"));
+    assertThat(interpreter.resolveELExpression("foo.bar", -1)).isEqualTo("test");
+  }
+
+  @Test
+  public void itGetsDictValuesWithEnumKeys() {
+    interpreter.getContext().put("foo", ImmutableMap.of(ErrorType.FATAL, "test"));
+    assertThat(interpreter.resolveELExpression("foo.FATAL", -1)).isEqualTo("test");
+  }
+
+  @Test
+  public void itGetsDictValuesWithEnumKeysInObjects() {
+    interpreter
+      .getContext()
+      .put("test", new TestClass(ImmutableMap.of(ErrorType.FATAL, "test")));
+    assertThat(interpreter.resolveELExpression("test.my_map.FATAL", -1))
+      .isEqualTo("test");
+  }
+
+  public class TestClass {
+    private Map<ErrorType, String> myMap;
+
+    public TestClass(Map<ErrorType, String> myMap) {
+      this.myMap = myMap;
+    }
+
+    public Map<ErrorType, String> getMyMap() {
+      return myMap;
+    }
+  }
+}