Add app setting name in constants file

Author: kamperiadis

src/main/java/com/microsoft/azure/functions/worker/Constants.java

@@ -9,4 +9,5 @@ private Constants(){}
     public final static String JAVA_LIBRARY_DIRECTORY = "/annotationLib";
     public final static String JAVA_LIBRARY_ARTIFACT_ID = "azure-functions-java-library";
     public final static String HAS_IMPLICIT_OUTPUT_QUALIFIED_NAME = "com.microsoft.azure.functions.annotation.HasImplicitOutput";
+    public final static String NULLABLE_VALUES_ENABLED_APP_SETTING = "FUNCTIONS_WORKER_NULLABLE_VALUES_ENABLED";
 }

src/main/java/com/microsoft/azure/functions/worker/binding/RpcHttpRequestDataSource.java

@@ -9,6 +9,7 @@
 import java.util.stream.Collectors;
 
 import com.microsoft.azure.functions.rpc.messages.NullableTypes;
+import com.microsoft.azure.functions.worker.Constants;
 import com.microsoft.azure.functions.worker.Util;
 import org.apache.commons.lang3.reflect.TypeUtils;
 
@@ -93,7 +94,7 @@ public Builder createResponseBuilder(HttpStatus status) {
 	}
 
 	private static Map<String, String> convertFromNullableMap(Map<String, NullableTypes.NullableString> nullableMap) {
-		if (Util.isTrue(System.getenv("FUNCTIONS_WORKER_NULLABLE_VALUES_ENABLED"))) {
+		if (Util.isTrue(System.getenv(Constants.NULLABLE_VALUES_ENABLED_APP_SETTING))) {
 			return nullableMap.entrySet().stream().collect(
 					Collectors.toMap(Map.Entry::getKey, e -> e.getValue().getValue())
 			);

src/test/java/com/microsoft/azure/functions/worker/binding/tests/RpcHttpRequestDataSourceTest.java

@@ -11,6 +11,7 @@
 import com.microsoft.azure.functions.HttpStatus;
 import com.microsoft.azure.functions.rpc.messages.RpcHttp;
 import com.microsoft.azure.functions.rpc.messages.TypedData;
+import com.microsoft.azure.functions.worker.Constants;
 import com.microsoft.azure.functions.worker.binding.*;
 import com.microsoft.azure.functions.worker.broker.JavaFunctionBroker;
 import com.microsoft.azure.functions.worker.handler.FunctionEnvironmentReloadRequestHandler;
@@ -63,7 +64,7 @@ public void rpcHttpDataSourceToHttpRequestMessageEnvSettingEnabled() throws Exce
     Map<String, String> existingVariables = System.getenv();
     Map<String, String> newEnvVariables = new HashMap<>();
     newEnvVariables.putAll(existingVariables);
-    newEnvVariables.put("FUNCTIONS_WORKER_NULLABLE_VALUES_ENABLED", "true");
+    newEnvVariables.put(Constants.NULLABLE_VALUES_ENABLED_APP_SETTING, "true");
     envHandler.setEnv(newEnvVariables);
     Method httpRequestMessageStringBodyMethod = getFunctionMethod("HttpRequestStringBody");
     Map<String, String> queryMap = new HashMap<String, String>() {{
@@ -97,7 +98,7 @@ public void rpcHttpDataSourceToHttpRequestMessageEnvSettingDisabled() throws Exc
     Map<String, String> existingVariables = System.getenv();
     Map<String, String> newEnvVariables = new HashMap<>();
     newEnvVariables.putAll(existingVariables);
-    newEnvVariables.put("FUNCTIONS_WORKER_NULLABLE_VALUES_ENABLED", "false");
+    newEnvVariables.put(Constants.NULLABLE_VALUES_ENABLED_APP_SETTING, "false");
     envHandler.setEnv(newEnvVariables);
     Method httpRequestMessageStringBodyMethod = getFunctionMethod("HttpRequestStringBody");
     Map<String, String> queryMap = new HashMap<String, String>() {{