ThrowForInvalidGroups: add unit test

This commit adds unit test for the |throwForInvalidGroups| function.

Tested: unit test passed

Signed-off-by: Nan Zhou <nanzhoumails@gmail.com>
Change-Id: I6c004dde1e3a27f60ee7de5cb1775940e19fffc8
diff --git a/test/user_mgr_test.cpp b/test/user_mgr_test.cpp
index f44282e..4595743 100644
--- a/test/user_mgr_test.cpp
+++ b/test/user_mgr_test.cpp
@@ -437,5 +437,20 @@
     EXPECT_NO_THROW(throwForInvalidPrivilege("priv-noaccess"));
 }
 
+TEST_F(UserMgrInTest, ThrowForInvalidGroupsThrowsWhenGroupIsInvalid)
+{
+    EXPECT_THROW(
+        throwForInvalidGroups({"whatever"}),
+        sdbusplus::xyz::openbmc_project::Common::Error::InvalidArgument);
+}
+
+TEST_F(UserMgrInTest, ThrowForInvalidGroupsNoThrowWhenGroupIsValid)
+{
+    EXPECT_NO_THROW(throwForInvalidGroups({"ipmi"}));
+    EXPECT_NO_THROW(throwForInvalidGroups({"ssh"}));
+    EXPECT_NO_THROW(throwForInvalidGroups({"redfish"}));
+    EXPECT_NO_THROW(throwForInvalidGroups({"web"}));
+}
+
 } // namespace user
 } // namespace phosphor