CCM-11492 Improve coverage

Author: nicki-nhs

frontend/src/__tests__/utils/message-plans.test.ts

@@ -13,6 +13,7 @@ import type {
   CascadeGroupName,
   Channel,
   ChannelType,
+  Result,
   RoutingConfig,
   RoutingConfigStatus,
 } from 'nhs-notify-backend-client';
@@ -146,6 +147,16 @@ describe('@utils/message-plans', () => {
         expect.any(Object)
       );
     });
+
+    it('should return undefined if API returns no data', async () => {
+      routingConfigApiMock.get.mockResolvedValueOnce(
+        {} as Result<RoutingConfig>
+      );
+
+      const response = await getMessagePlan(validRoutingConfigId);
+
+      expect(response).toBeUndefined();
+    });
   });
 
   describe('updateMessagePlan', () => {
@@ -182,6 +193,19 @@ describe('@utils/message-plans', () => {
       expect(loggerMock.error).not.toHaveBeenCalled();
     });
 
+    it('should return undefined if API returns no data', async () => {
+      routingConfigApiMock.update.mockResolvedValueOnce(
+        {} as Result<RoutingConfig>
+      );
+
+      const response = await updateMessagePlan(
+        validRoutingConfigId,
+        baseConfig
+      );
+
+      expect(response).toBeUndefined();
+    });
+
     it('should log and return undefined on API error', async () => {
       routingConfigApiMock.update.mockResolvedValueOnce({
         error: {