Add test for opening an ncml file with xml extension and change expec…

…ted behavior for file with other extension

tds/src/integrationTests/java/thredds/tds/TestS3Ncml.java

@@ -21,15 +21,23 @@ public void shouldOpenNcmlOnS3() {
   }
 
   @Test
-  public void shouldOpenNcmlWithOtherExtensionOnS3() {
-    final String endpoint = TestOnLocalServer.withHttpPath(S3_NCML_PATH + "testStandaloneNcml.otherExt.ascii?time");
+  public void shouldOpenNcmlWithXmlExtensionOnS3() {
+    final String endpoint = TestOnLocalServer.withHttpPath(S3_NCML_PATH + "testStandalone.xml.ascii?time");
     final byte[] content = TestOnLocalServer.getContent(endpoint, HttpServletResponse.SC_OK);
     final String stringContent = new String(content, StandardCharsets.UTF_8);
 
     assertThat(stringContent).contains("time[2]");
     assertThat(stringContent).contains("6, 18");
   }
 
+  @Test
+  public void shouldOpenNcmlWithOtherExtensionOnS3() {
+    // Can't currently open an S3 NcML file with an extension other than xml or ncml.
+    // Peaking inside the file to check if it's ncml is too slow
+    final String endpoint = TestOnLocalServer.withHttpPath(S3_NCML_PATH + "testStandaloneNcml.otherExt.ascii?time");
+    TestOnLocalServer.getContent(endpoint, HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+  }
+
   @Test
   public void shouldOpenAggregationWithRelativePathsOnS3() {
     final String endpoint = TestOnLocalServer.withHttpPath(S3_NCML_PATH + "nc/namExtract/test_agg.ncml.ascii?time");