Add test for when addParams is called with an existing key

packages/react-utils/src/hooks/tests/useSearchParams.test.tsx

@@ -31,11 +31,16 @@ test('useSimpleSearch works correctly', () => {
   current.addParam('key2', 'value2');
   expect(current.sParams.toString()).toEqual('key=value&key1=value1&key2=value2');
 
+  //Test that when we call addParams to an existing key we replace it instead of appending
+  current.addParam('key1', 'newValue3');
+  expect(current.sParams.toString()).toEqual('key=value&key1=newValue3&key2=value2');
+
   expect(history.location).toMatchObject({
     hash: '',
     key: expect.any(String),
     pathname: '/qr',
-    search: '?key=value?key=value&key1=value1?key=value&key1=value1&key2=value2',
+    search:
+      '?key=value?key=value&key1=value1?key=value&key1=value1&key2=value2?key=value&key1=newValue3&key2=value2',
     state: undefined,
   });
 
@@ -46,7 +51,7 @@ test('useSimpleSearch works correctly', () => {
     key: expect.any(String),
     pathname: '/qr',
     search:
-      '?key=value?key=value&key1=value1?key=value&key1=value1&key2=value2?key=value&key2=value2',
+      '?key=value?key=value&key1=value1?key=value&key1=value1&key2=value2?key=value&key1=newValue3&key2=value2?key=value&key2=value2',
     state: undefined,
   });
 });