- fixes an issue where the SDK would be expecting the wrong casing for the gaph error codes

src/main/java/com/microsoft/graph/http/GraphError.java

@@ -1,16 +1,16 @@
 // ------------------------------------------------------------------------------
 // Copyright (c) 2017 Microsoft Corporation
-// 
+//
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files (the "Software"), to deal
 // in the Software without restriction, including without limitation the rights
 // to use, copy, modify, merge, publish, distribute, sub-license, and/or sell
 // copies of the Software, and to permit persons to whom the Software is
 // furnished to do so, subject to the following conditions:
-// 
+//
 // The above copyright notice and this permission notice shall be included in
 // all copies or substantial portions of the Software.
-// 
+//
 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -25,6 +25,7 @@
 import com.google.gson.annotations.SerializedName;
 
 import com.microsoft.graph.core.GraphErrorCodes;
+import com.google.common.base.CaseFormat;
 import com.google.gson.annotations.Expose;
 
 import javax.annotation.Nullable;
@@ -54,21 +55,30 @@ public class GraphError {
 
     /**
      * Determine if the given error code is the one that is expected
-     * 
+     *
      * @param expectedCode the expected error code
      * @return <b>true</b> if the error code matches, and <b>false</b> if there was no match
      */
     public boolean isError(@Nonnull final GraphErrorCodes expectedCode) {
-        if (code.equalsIgnoreCase(expectedCode.toString())) {
+        if (transformErrorCodeCase(code).equalsIgnoreCase(expectedCode.toString())) {
             return true;
         }
         GraphInnerError innerError = innererror;
         while (null != innerError) {
-            if (innerError.code.equalsIgnoreCase(expectedCode.toString())) {
+            if (transformErrorCodeCase(innerError.code).equalsIgnoreCase(expectedCode.toString())) {
                 return true;
             }
             innerError = innerError.innererror;
         }
         return false;
     }
+    /**
+     * Transforms the text error code into the format expected by the value of the enum
+     * @param original original lowser Camel cased error code
+     * @return the resulting upper undescore cased error code
+     */
+    @Nonnull
+    protected String transformErrorCodeCase(@Nonnull final String original) {
+        return CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, original);
+    }
 }

src/test/java/com/microsoft/graph/http/GraphErrorTests.java

@@ -15,7 +15,7 @@ public class GraphErrorTests {
 	public void testIsError(){
         String expectedMessage = "test error message";
         GraphError error = new GraphError();
-        error.code = GraphErrorCodes.ACCESS_DENIED.toString();
+        error.code = "accessDenied"; // the code prop is lower camel cased https://docs.microsoft.com/en-us/graph/errors#code-property
         error.message = expectedMessage;
         assertTrue(error.isError(GraphErrorCodes.ACCESS_DENIED));
         assertEquals(expectedMessage, error.message);