fix: reject lazy option for useWatch as well

src/__tests__/core.test.tsx

@@ -377,7 +377,7 @@ describe('useWatchEffect', () => {
         () => {
           effectFn(counter.value);
         },
-        // @ts-ignore
+        // @ts-expect-error - lazy is not a valid option
         { lazy: true }
       )
     );
@@ -725,4 +725,36 @@ describe('useWatch', () => {
     // expect the hook to warn about using it inside a component that is not wrapped by makeReactive
     expect(consoleLog).toHaveBeenCalled();
   });
+  it('is reactive', () => {
+    const counter = ref(1);
+    const effectFn = jest.fn();
+
+    const { unmount } = renderHook(() =>
+      useWatch(
+        counter,
+        (...args) => {
+          effectFn(...args);
+        },
+        // @ts-expect-error - lazy is not a valid option
+        { lazy: true }
+      )
+    );
+
+    expect(effectFn).toBeCalledTimes(0);
+
+    act(() => {
+      counter.value++;
+    });
+
+    expect(effectFn).toBeCalledTimes(1);
+
+    unmount();
+    act(() => {
+      counter.value++;
+    });
+
+    expect(effectFn).toBeCalledTimes(1);
+
+    expect(consoleWarn).toBeCalled();
+  });
 });

src/core.ts

@@ -586,9 +586,15 @@ export const useWatch: UseWatchOverloads = <
   cb: WatchCallback<MapSources<T, false>, MapSources<T, Immediate>>,
   options?: WatchOptions<Immediate>
 ): void => {
+  if (options && 'lazy' in options && options.lazy) {
+    messages.warnLazyWatch();
+  }
   const reactiveRef = useRef<WatchStopHandle | null>(null);
   if (reactiveRef.current === null) {
-    reactiveRef.current = watch(sources, cb, options);
+    reactiveRef.current = watch(sources, cb, {
+      ...options,
+      lazy: false,
+    } as WatchOptions<Immediate>);
     if (getCurrentScope() !== undefined) {
       onScopeDispose(() => {
         reactiveRef.current = null;

src/messages.ts

@@ -5,6 +5,13 @@ const messages = {
         'Use watchEffect if you want to control the execution timing of the effect.'
     );
   },
+  warnLazyWatch() {
+    console.warn(
+      '"lazy" option is not supported for useWatch because the effect has to be run to collect dependencies. ' +
+        'Use the "immediate" option if you want to control callback execution. ' +
+        'Use watch if you want to control the execution timing of the effect.'
+    );
+  },
   warnInvalidWatchSource(s: unknown) {
     console.warn(
       'Invalid watch source: ',