Fix the issue that sonic_platform is not installed on vs image

tests/sfp_test.py

@@ -495,6 +495,13 @@ def test_sfp_eeprom_dom_all(self):
         assert result.exit_code == 0
         assert "\n".join([ l.rstrip() for l in result.output.split('\n')]) == test_sfp_eeprom_dom_all_output
 
+    def test_is_rj45_port(self):
+        import utilities_common.platform_sfputil_helper as platform_sfputil_helper
+        platform_sfputil_helper.platform_chassis = None
+        if 'sonic_platform' in sys.modules:
+            sys.modules.pop('sonic_platform')
+        assert platform_sfputil_helper.is_rj45_port("Ethernet0") == False
+
     @classmethod
     def teardown_class(cls):
         print("TEARDOWN")

utilities_common/platform_sfputil_helper.py

@@ -111,12 +111,18 @@ def is_rj45_port(port_name):
     global platform_sfp_base
     global platform_sfputil_loaded
 
-    if not platform_chassis:
-        import sonic_platform
-        platform_chassis = sonic_platform.platform.Platform().get_chassis()
-    if not platform_sfp_base:
-        import sonic_platform_base
-        platform_sfp_base = sonic_platform_base.sfp_base.SfpBase
+    try:
+        if not platform_chassis:
+            import sonic_platform
+            platform_chassis = sonic_platform.platform.Platform().get_chassis()
+        if not platform_sfp_base:
+            import sonic_platform_base
+            platform_sfp_base = sonic_platform_base.sfp_base.SfpBase
+    except ModuleNotFoundError as e:
+        # This method is referenced by intfutil which is called on vs image
+        # However, there is no platform API supported on vs image
+        # So False is returned in such case
+        return False
 
     if platform_chassis and platform_sfp_base:
         if not platform_sfputil: