Fix accidental double network call with useLazyQuery on some calls of the execute function

.changeset/honest-turtles-move.md

@@ -0,0 +1,5 @@
+---
+"@apollo/client": patch
+---
+
+Fix issue in `useLazyQuery` that results in a double network call when calling the execute function with no arguments after having called it previously with another set of arguments.

.size-limits.json

@@ -1,4 +1,4 @@
 {
-  "dist/apollo-client.min.cjs": 39061,
+  "dist/apollo-client.min.cjs": 39067,
   "import { ApolloClient, InMemoryCache, HttpLink } from \"dist/index.js\" (production)": 32559
 }

src/react/hooks/__tests__/useLazyQuery.test.tsx

@@ -1483,6 +1483,83 @@ describe("useLazyQuery Hook", () => {
     expect(fetchCount).toBe(1);
   });
 
+  // https://github.com/apollographql/apollo-client/issues/9448
+  it.each(["network-only", "no-cache", "cache-and-network"] as const)(
+    "does not issue multiple network calls when calling execute again without variables with a %s fetch policy",
+    async (fetchPolicy) => {
+      interface Data {
+        user: { id: string; name: string };
+      }
+
+      interface Variables {
+        id?: string;
+      }
+
+      const query: TypedDocumentNode<Data, Variables> = gql`
+        query UserQuery($id: ID) {
+          user(id: $id) {
+            id
+            name
+          }
+        }
+      `;
+
+      let fetchCount = 0;
+
+      const link = new ApolloLink((operation) => {
+        fetchCount++;
+        return new Observable((observer) => {
+          setTimeout(() => {
+            observer.next({
+              data: {
+                user: { id: operation.variables.id || null, name: "John Doe" },
+              },
+            });
+            observer.complete();
+          }, 20);
+        });
+      });
+
+      const client = new ApolloClient({
+        link,
+        cache: new InMemoryCache(),
+      });
+
+      const { result } = renderHook(
+        () => useLazyQuery(query, { fetchPolicy }),
+        {
+          wrapper: ({ children }) => (
+            <ApolloProvider client={client}>{children}</ApolloProvider>
+          ),
+        }
+      );
+
+      const [execute] = result.current;
+
+      await act(() => execute({ variables: { id: "2" } }));
+
+      expect(fetchCount).toBe(1);
+
+      await waitFor(() => {
+        expect(result.current[1].data).toEqual({
+          user: { id: "2", name: "John Doe" },
+        });
+      });
+
+      expect(fetchCount).toBe(1);
+
+      await act(() => execute());
+
+      await waitFor(() => {
+        expect(result.current[1].data).toEqual({
+          user: { id: "2", name: "John Doe" },
+        });
+      });
+
+      expect(fetchCount).toBe(2);
+    }
+  );
+
   describe("network errors", () => {
     async function check(errorPolicy: ErrorPolicy) {
       const networkError = new Error("from the network");

src/react/hooks/useLazyQuery.ts

@@ -129,7 +129,9 @@ export function useLazyQuery<
             fetchPolicy: executeOptions.fetchPolicy || initialFetchPolicy,
           }
         : {
-            fetchPolicy: initialFetchPolicy,
+            ...execOptionsRef.current,
+            fetchPolicy:
+              execOptionsRef.current?.fetchPolicy || initialFetchPolicy,
           };
 
       const options = mergeOptions(optionsRef.current, {