diff --git a/src/index.ts b/src/index.ts
index fa69a31..3b1191d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,2 +1,3 @@
 export * from "./core";
 export * from "./deepSignal";
+export * from "./watch"
diff --git a/src/test/index.test.ts b/src/test/index.test.ts
index 5382b57..1f91692 100644
--- a/src/test/index.test.ts
+++ b/src/test/index.test.ts
@@ -1,7 +1,6 @@
 import { deepSignal, peek, RevertDeepSignal, shallow } from "../index"
-import { describe, it, expect, beforeEach, test } from "vitest"
+import { describe, it, expect, beforeEach } from "vitest"
 import { signal, Signal, effect } from "..";
-import { watch } from "../watch";
 type Store = {
 	a?: number;
 	nested: { b?: number };
@@ -1112,25 +1111,3 @@ describe("deepsignal/core", () => {
 		});
 	});
 });
-
-
-describe('watch', () => {
-	test('abc', () => {
-		const store = deepSignal({
-			userinfo: {
-				name: "tom"
-			}
-		})
-		const stop = watch(store, (newValue, oldValue) => {
-			console.log('newValue', newValue);
-			console.log('oldValue', oldValue);
-		}, {
-			immediate: true,
-			deep: true,
-		})
-
-		store.userinfo.name = "jon"
-		stop()
-		store.userinfo.name = 'jon2'
-	})
-})
diff --git a/src/test/watch.test.ts b/src/test/watch.test.ts
new file mode 100644
index 0000000..2e942e1
--- /dev/null
+++ b/src/test/watch.test.ts
@@ -0,0 +1,64 @@
+import { describe, expect, it } from "vitest";
+import { deepSignal } from "../deepSignal";
+import { watch } from "../watch";
+
+describe('watch', () => {
+  it('watch immediate', () => {
+    const store = deepSignal({
+      userinfo: {
+        name: "tom"
+      }
+    })
+    let val!: string
+    watch(store, (newValue) => {
+      val = newValue.userinfo.name
+    }, {
+      immediate: true,
+      deep: true
+    })
+    expect(val).toEqual('tom')
+  })
+  it('watch deep', () => {
+    const store = deepSignal({
+      userinfo: {
+        name: "tom"
+      }
+    })
+    let val!: string
+    watch(store, (newValue) => {
+      val = newValue.userinfo.name
+    }, {
+      immediate: true,
+      deep: true
+    })
+    let value2!: string
+    watch(store, (newValue) => {
+      value2 = newValue.userinfo.name
+    }, { immediate: true })
+    expect(val).toEqual('tom')
+    store.userinfo.name = "jon"
+    expect(val).toEqual('jon')
+    expect(value2).toEqual('tom')
+  })
+
+  it('watch once', () => {
+    const store = deepSignal({
+      userinfo: {
+        name: "tom"
+      }
+    })
+    let val!: string
+    watch(store, (newValue) => {
+      val = newValue.userinfo.name
+    }, {
+      immediate: true,
+      deep: true,
+      once: true
+    })
+
+    expect(val).toEqual("tom")
+    store.userinfo.name = "jon"
+    expect(val).not.toEqual("jon")
+    expect(val).toEqual("tom")
+  })
+})
diff --git a/src/utils.ts b/src/utils.ts
index ef47787..5c45714 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,6 +1,3 @@
-import { ReactiveFlags } from "./contents"
-import { isSignal } from "./core"
-
 export const objectToString: typeof Object.prototype.toString =
   Object.prototype.toString
 export const toTypeString = (value: unknown): string =>
@@ -40,41 +37,3 @@ export const isPlainObject = (val: unknown): val is object =>
 
 export const hasChanged = (value: any, oldValue: any): boolean =>
   !Object.is(value, oldValue)
-
-export function traverse(
-  value: unknown,
-  depth: number = Infinity,
-  seen?: Set<unknown>,
-): unknown {
-  if (depth <= 0 || !isObject(value) || (value as any)[ReactiveFlags.SKIP]) {
-    return value
-  }
-
-  seen = seen || new Set()
-  if (seen.has(value)) {
-    return value
-  }
-  seen.add(value)
-  depth--
-  if (isSignal(value)) {
-    traverse(value.value, depth, seen)
-  } else if (isArray(value)) {
-    for (let i = 0; i < value.length; i++) {
-      traverse(value[i], depth, seen)
-    }
-  } else if (isSet(value) || isMap(value)) {
-    value.forEach((v: any) => {
-      traverse(v, depth, seen)
-    })
-  } else if (isPlainObject(value)) {
-    for (const key in value) {
-      traverse(value[key], depth, seen)
-    }
-    for (const key of Object.getOwnPropertySymbols(value)) {
-      if (Object.prototype.propertyIsEnumerable.call(value, key)) {
-        traverse(value[key as any], depth, seen)
-      }
-    }
-  }  
-  return value
-}
diff --git a/src/watch.ts b/src/watch.ts
index 646e2f8..19d2a67 100644
--- a/src/watch.ts
+++ b/src/watch.ts
@@ -1,6 +1,7 @@
-import { Computed, Effect, isSignal, Signal, } from './core';
-import { hasChanged, isArray, traverse } from './utils';
+import { Computed, Effect, isSignal, Signal } from './core';
+import { hasChanged, isArray, isMap, isObject, isPlainObject, isSet } from './utils';
 import { isDeepSignal, isShallow } from "./deepSignal"
+import { ReactiveFlags } from './contents';
 
 export type OnCleanup = (cleanupFn: () => void) => void
 export type WatchEffect = (onCleanup: OnCleanup) => void
@@ -38,7 +39,6 @@ export function watch(
 
   let effect!: Effect
   let getter!: () => any
-  // let boundCleanup: typeof onWatcherCleanup
   let forceTrigger = false
   let isMultiSource = false
 
@@ -150,3 +150,42 @@ export function watch(
   }
   return watchHandle
 }
+
+
+export function traverse(
+  value: unknown,
+  depth: number = Infinity,
+  seen?: Set<unknown>,
+): unknown {
+  if (depth <= 0 || !isObject(value) || (value as any)[ReactiveFlags.SKIP]) {
+    return value
+  }
+
+  seen = seen || new Set()
+  if (seen.has(value)) {
+    return value
+  }
+  seen.add(value)
+  depth--
+  if (isSignal(value)) {
+    traverse(value.value, depth, seen)
+  } else if (isArray(value)) {
+    for (let i = 0; i < value.length; i++) {
+      traverse(value[i], depth, seen)
+    }
+  } else if (isSet(value) || isMap(value)) {
+    value.forEach((v: any) => {
+      traverse(v, depth, seen)
+    })
+  } else if (isPlainObject(value)) {
+    for (const key in value) {
+      traverse(value[key], depth, seen)
+    }
+    for (const key of Object.getOwnPropertySymbols(value)) {
+      if (Object.prototype.propertyIsEnumerable.call(value, key)) {
+        traverse(value[key as any], depth, seen)
+      }
+    }
+  }
+  return value
+}