Added test for invalid configuration

Author: gertjanal

core/trino-main/src/main/java/io/trino/security/GroupProviderManager.java

@@ -97,10 +97,10 @@ void loadConfiguredGroupProvider(File groupProviderFile)
                     .filter(groupCase::equalsIgnoreCase)
                     .map(Case::valueOf)
                     .findFirst()
-                    .orElseThrow(() -> new IllegalArgumentException(format("Group provider configuration %s does not contain valid %s. Allowed: %s",
+                    .orElseThrow(() -> new IllegalArgumentException(format("Group provider configuration %s does not contain valid %s. Expected one of: %s",
                             groupProviderFile.getAbsoluteFile(),
                             GROUP_PROVIDER_PROPERTY_GROUP_CASE,
-                            stream(Case.values()).map(Case::toString).collect(joining(", ")))));
+                            stream(Case.values()).map(Case::toString).collect(joining(", ", "[", "]")))));
         }
 
         setConfiguredGroupProvider(groupProviderName, properties);

core/trino-main/src/test/java/io/trino/security/TestGroupProviderManager.java

@@ -27,7 +27,10 @@
 import java.nio.file.Files;
 import java.util.Map;
 
+import static java.lang.String.format;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 public class TestGroupProviderManager
 {
@@ -101,4 +104,25 @@ void setTestGroupProviderLowerCase() throws Exception
             assertThat(groupProviderManager.getGroups("Bob")).isEqualTo(ImmutableSet.of("test", "bob"));
         }
     }
+
+    @Test
+    void setTestGroupProviderInvalidCase() throws Exception
+    {
+        try (TempFile tempFile = new TempFile()) {
+            Files.writeString(tempFile.path(), """
+                group-provider.name=testGroupProvider
+                group-provider.group-case=invalid
+                """);
+
+            GroupProviderManager groupProviderManager = new GroupProviderManager(new SecretsResolver(ImmutableMap.of()));
+            groupProviderManager.addGroupProviderFactory(TEST_GROUP_PROVIDER_FACTORY);
+
+            IllegalArgumentException ex = assertThrows(IllegalArgumentException.class, () ->
+                groupProviderManager.loadConfiguredGroupProvider(tempFile.file()));
+
+            assertEquals(format(
+                "Group provider configuration %s does not contain valid group-provider.group-case. Expected one of: [KEEP, LOWER, UPPER]",
+                tempFile.path().toAbsolutePath()), ex.getMessage());
+        }
+    }
 }