diff --git a/README.md b/README.md
index 7d78e51..9ae334b 100644
--- a/README.md
+++ b/README.md
@@ -143,20 +143,18 @@
 13. `mouse_press` / `mouse_release` / `mouse_move` / `mouse_move_rel` / `mouse_move_rel_chain`
     > similar to the drag features. These mouse features is only dispatched events, not the real mouse action.
 
-
-
-
 </details>
 
+[More Examples](https://github.com/ClericPy/ichrome/blob/master/examples_async.py)
+
 ```python
 from ichrome import AsyncChromeDaemon, AsyncChrome
 import asyncio
 
 
 async def main():
-    # async with AsyncChromeDaemon() as chromed:
-    # If there is no operation for chromed, it can be omitted for short
-    async with AsyncChromeDaemon(headless=False):
+    # If there is an existing daemon, such as `python -m ichrome`, the `async with AsyncChromeDaemon` context can be omitted.
+    async with AsyncChromeDaemon():
         # connect to an opened chrome
         async with AsyncChrome() as chrome:
             tab = await chrome.new_tab(url="https://github.com/ClericPy")
diff --git a/examples/test_async.py b/examples/test_async.py
deleted file mode 100644
index a0bcc8a..0000000
--- a/examples/test_async.py
+++ /dev/null
@@ -1,215 +0,0 @@
-import asyncio
-import os
-import sys
-
-# use local ichrome module
-sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
-os.chdir("..")  # for reuse exiting user data dir
-
-
-async def test_examples():
-    from ichrome import AsyncChrome as Chrome
-    from ichrome import AsyncTab as Tab
-    from ichrome import AsyncChromeDaemon, Tag, logger
-    logger.setLevel('DEBUG')
-    # Tab._log_all_recv = True
-    port = 9222
-
-    async with AsyncChromeDaemon(host="127.0.0.1", port=port, max_deaths=1):
-        # ===================== Chrome Test Cases =====================
-        async with Chrome() as chrome:
-            assert str(chrome) == '<Chrome(connected): http://127.0.0.1:9222>'
-            assert chrome.server == 'http://127.0.0.1:9222'
-            try:
-                await chrome.version
-            except AttributeError as e:
-                assert str(
-                    e
-                ) == 'Chrome has not connected. `await chrome.connect()` before request.'
-            # waiting chrome launching
-            for _ in range(5):
-                connected = await chrome.connect()
-                if connected:
-                    break
-                await asyncio.sleep(1)
-            assert connected is True
-            version = await chrome.version
-            assert isinstance(version, dict) and 'Browser' in version
-            ok = await chrome.check()
-            assert ok is True
-            ok = await chrome.ok
-            assert ok is True
-            resp = await chrome.get_server('json')
-            assert isinstance(resp.json(), list)
-            tabs1: Tab = await chrome.get_tabs()
-            tabs2: Tab = await chrome.tabs
-            assert tabs1 == tabs2
-            tab0: Tab = tabs1[0]
-            tab1: Tab = await chrome.new_tab()
-            assert isinstance(tab1, Tab)
-            await asyncio.sleep(1)
-            await chrome.activate_tab(tab0)
-            async with chrome.connect_tabs([tab0, tab1]):
-                assert (await tab0.current_url) == 'about:blank'
-                assert (await tab1.current_url) == 'about:blank'
-            async with chrome.connect_tabs(tab0):
-                assert await tab0.current_url == 'about:blank'
-            await chrome.close_tab(tab1)
-            # ===================== Tab Test Cases =====================
-            tab: Tab = await chrome.new_tab()
-            assert tab.ws is None
-            async with tab():
-                assert tab.ws
-            assert tab.ws is None
-            # also work: async with tab.connect():
-            async with tab():
-                assert tab.status == 'connected'
-                assert tab.msg_id == tab.msg_id - 1
-                assert await tab.refresh_tab_info()
-
-                # watch the tabs switch
-                await tab.activate_tab()
-                await asyncio.sleep(.2)
-                await tab0.activate_tab()
-                await asyncio.sleep(.2)
-                await tab.activate_tab()
-
-                assert await tab.send('Network.enable') == {
-                    'id': 3,
-                    'result': {}
-                }
-                await tab.clear_browser_cookies()
-                assert len(await tab.get_cookies(urls='http://python.org')) == 0
-                assert await tab.set_cookie(
-                    'test', 'test_value', url='http://python.org')
-                assert await tab.set_cookie(
-                    'test2', 'test_value', url='http://python.org')
-                assert len(await tab.get_cookies(urls='http://python.org')) == 2
-                assert await tab.delete_cookies('test', url='http://python.org')
-                assert len(await tab.get_cookies(urls='http://python.org')) == 1
-                # get all Browser cookies
-                assert len(await tab.get_all_cookies()) > 0
-                # disable Network
-                assert await tab.disable('Network')
-                # set new url for this tab, timeout will stop loading
-                assert await tab.set_url('http://python.org', timeout=2)
-                # reload the page
-                assert await tab.reload(timeout=2)
-                # here should be press OK by human in 10 secs, get the returned result
-                js_result = await tab.js('document.title', timeout=3)
-                # {'id': 18, 'result': {'result': {'type': 'string', 'value': 'Welcome to Python.org'}}}
-                assert 'result' in js_result
-                # inject JS timeout return None
-                assert (await tab.js('alert()', timeout=0.1)) is None
-                # close the alert dialog
-                await tab.enable('Page')
-                await tab.send('Page.handleJavaScriptDialog', accept=True)
-                # querySelectorAll with JS, return list of Tag object
-                tag_list = await tab.querySelectorAll('#id-search-field')
-                assert tag_list[0].tagName == 'input'
-                # querySelectorAll with JS, index arg is Not None, return Tag or None
-                one_tag = await tab.querySelectorAll(
-                    '#id-search-field', index=0)
-                assert isinstance(one_tag, Tag)
-                # inject js url: vue.js
-                # get window.Vue variable before injecting
-                vue_obj = await tab.js('window.Vue')
-                # {'id': 22, 'result': {'result': {'type': 'undefined'}}}
-                assert 'undefined' in str(vue_obj)
-                assert await tab.inject_js_url(
-                    'https://cdn.staticfile.org/vue/2.6.10/vue.min.js',
-                    timeout=3)
-                vue_obj = await tab.js('window.Vue')
-                # {'id': 23, 'result': {'result': {'type': 'function', 'className': 'Function', 'description': 'function wn(e){this._init(e)}', 'objectId': '{"injectedScriptId":1,"id":1}'}}}
-                assert 'Function' in str(vue_obj)
-
-                # update title
-                await tab.js("document.title = 'Press about'")
-                assert (await tab.current_title) == 'Press about'
-
-                # wait_response by filter_function
-                # {'method': 'Network.responseReceived', 'params': {'requestId': '1000003000.69', 'loaderId': 'D7814CD633EDF3E699523AF0C4E9DB2C', 'timestamp': 207483.974238, 'type': 'Script', 'response': {'url': 'https://www.python.org/static/js/libs/masonry.pkgd.min.js', 'status': 200, 'statusText': '', 'headers': {'date': 'Sat, 05 Oct 2019 08:18:34 GMT', 'via': '1.1 vegur, 1.1 varnish, 1.1 varnish', 'last-modified': 'Tue, 24 Sep 2019 18:31:03 GMT', 'server': 'nginx', 'age': '290358', 'etag': '"5d8a60e7-6643"', 'x-served-by': 'cache-iad2137-IAD, cache-tyo19928-TYO', 'x-cache': 'HIT, HIT', 'content-type': 'application/x-javascript', 'status': '200', 'cache-control': 'max-age=604800, public', 'accept-ranges': 'bytes', 'x-timer': 'S1570263515.866582,VS0,VE0', 'content-length': '26179', 'x-cache-hits': '1, 170'}, 'mimeType': 'application/x-javascript', 'connectionReused': False, 'connectionId': 0, 'remoteIPAddress': '151.101.108.223', 'remotePort': 443, 'fromDiskCache': True, 'fromServiceWorker': False, 'fromPrefetchCache': False, 'encodedDataLength': 0, 'timing': {'requestTime': 207482.696803, 'proxyStart': -1, 'proxyEnd': -1, 'dnsStart': -1, 'dnsEnd': -1, 'connectStart': -1, 'connectEnd': -1, 'sslStart': -1, 'sslEnd': -1, 'workerStart': -1, 'workerReady': -1, 'sendStart': 0.079, 'sendEnd': 0.079, 'pushStart': 0, 'pushEnd': 0, 'receiveHeadersEnd': 0.836}, 'protocol': 'h2', 'securityState': 'unknown'}, 'frameId': 'A2971702DE69F008914F18EAE6514DD5'}}
-                async def cb(request):
-                    if request:
-                        await tab.wait_request_loading(request, 5)
-                        ok = 'Masonry PACKAGED' in (
-                            await tab.get_response(request))['result']['body']
-                        logger.warning(
-                            f'check wait_response callback, get_response {ok}')
-                        assert ok
-                    else:
-                        raise ValueError
-
-                # listening response
-                def filter_function(r):
-                    ok = 'www.python.org/static/js/libs/masonry.pkgd.min.js' in r[
-                        'params']['response']['url']
-                    return print('get response url:',
-                                 r['params']['response']['url'], ok) or ok
-
-                task = asyncio.ensure_future(
-                    tab.wait_response(
-                        filter_function=filter_function,
-                        callback_function=cb,
-                        timeout=10),
-                    loop=tab.loop)
-                await tab.click('#about>a')
-                await tab.wait_loading(2)
-                await task
-                # click download link, without wait_loading.
-                # request
-                # {'method': 'Network.responseReceived', 'params': {'requestId': '2FAFC4FC410A6DEDE88553B1836C530B', 'loaderId': '2FAFC4FC410A6DEDE88553B1836C530B', 'timestamp': 212239.182469, 'type': 'Document', 'response': {'url': 'https://www.python.org/downloads/', 'status': 200, 'statusText': '', 'headers': {'status': '200', 'server': 'nginx', 'content-type': 'text/html; charset=utf-8', 'x-frame-options': 'DENY', 'cache-control': 'max-age=604800, public', 'via': '1.1 vegur\n1.1 varnish\n1.1 varnish', 'accept-ranges': 'bytes', 'date': 'Sat, 05 Oct 2019 10:51:48 GMT', 'age': '282488', 'x-served-by': 'cache-iad2139-IAD, cache-hnd18720-HND', 'x-cache': 'MISS, HIT', 'x-cache-hits': '0, 119', 'x-timer': 'S1570272708.444646,VS0,VE0', 'content-length': '113779'}, 'mimeType': 'text/html', 'connectionReused': False, 'connectionId': 0, 'remoteIPAddress': '123.23.54.43', 'remotePort': 443, 'fromDiskCache': True, 'fromServiceWorker': False, 'fromPrefetchCache': False, 'encodedDataLength': 0, 'timing': {'requestTime': 212239.179388, 'proxyStart': -1, 'proxyEnd': -1, 'dnsStart': -1, 'dnsEnd': -1, 'connectStart': -1, 'connectEnd': -1, 'sslStart': -1, 'sslEnd': -1, 'workerStart': -1, 'workerReady': -1, 'sendStart': 0.392, 'sendEnd': 0.392, 'pushStart': 0, 'pushEnd': 0, 'receiveHeadersEnd': 0.975}, 'protocol': 'h2', 'securityState': 'secure', 'securityDetails': {'protocol': 'TLS 1.2', 'keyExchange': 'ECDHE_RSA', 'keyExchangeGroup': 'X25519', 'cipher': 'AES_128_GCM', 'certificateId': 0, 'subjectName': 'www.python.org', 'sanList': ['www.python.org', 'docs.python.org', 'bugs.python.org', 'wiki.python.org', 'hg.python.org', 'mail.python.org', 'pypi.python.org', 'packaging.python.org', 'login.python.org', 'discuss.python.org', 'us.pycon.org', 'pypi.io', 'docs.pypi.io', 'pypi.org', 'docs.pypi.org', 'donate.pypi.org', 'devguide.python.org', 'www.bugs.python.org', 'python.org'], 'issuer': 'DigiCert SHA2 Extended Validation Server CA', 'validFrom': 1537228800, 'validTo': 1602676800, 'signedCertificateTimestampList': [], 'certificateTransparencyCompliance': 'unknown'}}, 'frameId': '882CFDEEA07EB00A5E7510ADD2A39F22'}}
-                # response
-                # {'id': 30, 'result': {'body': '<!doctype html>\n<!--[if lt IE 7]>   <html class="no-js ie6 lt-ie...', 'base64Encoded': False}}
-                # test set_ua
-                await tab.set_ua('Test UA')
-                await tab.add_js_onload(source='window.title=123456789')
-                await tab.set_url('http://httpbin.org/forms/post')
-                assert (await tab.get_variable('window.title')) == 123456789
-                html = await tab.get_html()
-                assert 'Customer name:' in html
-                # test double click some positions. test keyboard_send input
-                rect = await tab.get_bounding_client_rect('[type="email"]')
-                await tab.mouse_click(rect['left'], rect['top'], count=1)
-                await tab.keyboard_send(text='1')
-                await tab.keyboard_send(text='2')
-                await tab.keyboard_send(text='3')
-                await tab.mouse_click(rect['left'], rect['top'], count=2)
-                selection = await tab.get_variable(
-                    'window.getSelection().toString()')
-                assert selection == '123'
-                # test set_headers
-                await tab.set_headers({'A': '1', 'B': '2'})
-                await tab.set_url('http://httpbin.org/get')
-                html = await tab.get_html()
-                assert '"A": "1"' in html and '"B": "2"' in html
-                # screenshot
-                await tab.set_url('http://python.org')
-                await tab.wait_loading(1)
-                screen = await tab.screenshot()
-                part = await tab.screenshot_element('.site-headline')
-                assert screen
-                assert part
-                assert len(screen) > len(part)
-                # draw
-                await tab.set_url('https://awwapp.com/')
-                await tab.wait_loading(1, timeout_stop_loading=True)
-                await tab.mouse_click(5, 5)
-                walker = await tab.mouse_drag_rel_chain(320, 145).move(50, 0, 0.2).move(
-                    0, 50, 0.2).move(-50, 0, 0.2).move(0, -50, 0.2)
-                await walker.move(50 * 1.414, 50 * 1.414, 0.2)
-                # clear cache
-                assert await tab.clear_browser_cache()
-                # close tab
-                await tab.close()
-            # close_browser gracefully, I have no more need of chrome instance
-            await chrome.close_browser()
-            # await chrome.kill()
-            sep = f'\n{"=" * 80}\n'
-            logger.critical(
-                f'{sep}Congratulations, all test cases passed.{sep}')
-
-
-if __name__ == "__main__":
-    loop = asyncio.get_event_loop()
-    loop.run_until_complete(test_examples())
diff --git a/examples_async.py b/examples_async.py
new file mode 100644
index 0000000..0df4015
--- /dev/null
+++ b/examples_async.py
@@ -0,0 +1,257 @@
+import asyncio
+from typing import List
+
+from ichrome import AsyncChrome as Chrome
+from ichrome import AsyncChromeDaemon
+from ichrome import AsyncTab as Tab
+from ichrome import Tag, logger
+
+logger.setLevel('DEBUG')
+# Tab._log_all_recv = True
+port = 9222
+
+
+async def test_chrome(chrome: Chrome):
+    assert str(chrome) == '<Chrome(connected): http://127.0.0.1:9222>'
+    assert chrome.server == 'http://127.0.0.1:9222'
+    version = await chrome.version
+    assert isinstance(version, dict) and 'Browser' in version
+    ok = await chrome.check()
+    assert ok is True
+    ok = await chrome.ok
+    assert ok is True
+    resp = await chrome.get_server('json')
+    assert isinstance(resp.json(), list)
+    tabs1: List[Tab] = await chrome.get_tabs()
+    tabs2: List[Tab] = await chrome.tabs
+    assert tabs1 == tabs2
+    tab0: Tab = await chrome.get_tab(0)
+    assert tabs1[0] == tab0
+    tab1: Tab = await chrome.new_tab()
+    assert isinstance(tab1, Tab)
+    await asyncio.sleep(0.2)
+    await chrome.activate_tab(tab0)
+    # test batch connect multiple tabs
+    async with chrome.connect_tabs([tab0, tab1]):
+        assert (await tab0.current_url) == 'about:blank'
+        assert (await tab1.current_url) == 'about:blank'
+        # watch the tabs switch
+        await tab1.activate_tab()
+        await asyncio.sleep(.2)
+        await tab0.activate_tab()
+        await asyncio.sleep(.2)
+        await tab1.activate_tab()
+    # test connect single tab
+    async with chrome.connect_tabs(tab0):
+        assert await tab0.current_url == 'about:blank'
+    await chrome.close_tab(tab1)
+
+
+async def test_tab_ws(tab: Tab):
+    # test msg_id auto increase
+    assert tab.msg_id == tab.msg_id - 1
+    assert tab.status != 'connected'
+    assert tab.ws is None
+    async with tab():
+        assert tab.ws
+        assert tab.status == 'connected'
+    # assert no connection out of async context.
+    assert tab.ws is None
+    assert tab.status != 'connected'
+
+
+async def test_send_msg(tab: Tab):
+    # test send msg
+    assert (await tab.send('Network.enable'))['result'] == {}
+    # disable Network
+    await tab.disable('Network')
+
+
+async def test_tab_cookies(tab: Tab):
+    await tab.clear_browser_cookies()
+    assert len(await tab.get_cookies(urls='http://python.org')) == 0
+    assert await tab.set_cookie('test', 'test_value', url='http://python.org')
+    assert await tab.set_cookie('test2', 'test_value', url='http://python.org')
+    assert len(await tab.get_cookies(urls='http://python.org')) == 2
+    assert await tab.delete_cookies('test', url='http://python.org')
+    assert len(await tab.get_cookies(urls='http://python.org')) == 1
+    # get all Browser cookies
+    assert len(await tab.get_all_cookies()) > 0
+
+
+async def test_tab_set_url(tab: Tab):
+    # set new url for this tab, timeout will stop loading for timeout_stop_loading defaults to True
+    assert await tab.set_url('http://python.org', timeout=5)
+    # reload the page
+    assert await tab.reload(timeout=2)
+
+
+async def test_tab_js(tab: Tab):
+    # test js update title
+    await tab.js("document.title = 'abc'")
+    new_title = await tab.current_title
+    # test refresh_tab_info for tab meta info
+    assert tab.title != new_title
+    assert await tab.refresh_tab_info()
+    assert tab.title == new_title
+    # inject JS timeout return None
+    assert (await tab.js('alert()', timeout=0.1)) is None
+    # close the alert dialog
+    assert await tab.handle_dialog(accept=True)
+    # inject js url: vue.js
+    # get window.Vue variable before injecting
+    vue_obj = await tab.js('window.Vue')
+    # {'id': 22, 'result': {'result': {'type': 'undefined'}}}
+    assert 'undefined' in str(vue_obj)
+    assert await tab.inject_js_url(
+        'https://cdn.staticfile.org/vue/2.6.10/vue.min.js', timeout=3)
+    vue_obj = await tab.js('window.Vue')
+    # {'id': 23, 'result': {'result': {'type': 'function', 'className': 'Function', 'description': 'function wn(e){this._init(e)}', 'objectId': '{"injectedScriptId":1,"id":1}'}}}
+    assert 'Function' in str(vue_obj)
+    # querySelectorAll with JS, return list of Tag object
+    tags = await tab.querySelectorAll('#id-search-field')
+    assert isinstance(tags[0], Tag)
+    # querySelectorAll with JS, index arg is Not None, return Tag or None
+    one_tag = await tab.querySelectorAll('#id-search-field', index=0)
+    assert isinstance(one_tag, Tag)
+
+
+async def test_wait_response(tab: Tab):
+    # wait_response with filter_function
+    # raw response: {'method': 'Network.responseReceived', 'params': {'requestId': '1000003000.69', 'loaderId': 'D7814CD633EDF3E699523AF0C4E9DB2C', 'timestamp': 207483.974238, 'type': 'Script', 'response': {'url': 'https://www.python.org/static/js/libs/masonry.pkgd.min.js', 'status': 200, 'statusText': '', 'headers': {'date': 'Sat, 05 Oct 2019 08:18:34 GMT', 'via': '1.1 vegur, 1.1 varnish, 1.1 varnish', 'last-modified': 'Tue, 24 Sep 2019 18:31:03 GMT', 'server': 'nginx', 'age': '290358', 'etag': '"5d8a60e7-6643"', 'x-served-by': 'cache-iad2137-IAD, cache-tyo19928-TYO', 'x-cache': 'HIT, HIT', 'content-type': 'application/x-javascript', 'status': '200', 'cache-control': 'max-age=604800, public', 'accept-ranges': 'bytes', 'x-timer': 'S1570263515.866582,VS0,VE0', 'content-length': '26179', 'x-cache-hits': '1, 170'}, 'mimeType': 'application/x-javascript', 'connectionReused': False, 'connectionId': 0, 'remoteIPAddress': '151.101.108.223', 'remotePort': 443, 'fromDiskCache': True, 'fromServiceWorker': False, 'fromPrefetchCache': False, 'encodedDataLength': 0, 'timing': {'requestTime': 207482.696803, 'proxyStart': -1, 'proxyEnd': -1, 'dnsStart': -1, 'dnsEnd': -1, 'connectStart': -1, 'connectEnd': -1, 'sslStart': -1, 'sslEnd': -1, 'workerStart': -1, 'workerReady': -1, 'sendStart': 0.079, 'sendEnd': 0.079, 'pushStart': 0, 'pushEnd': 0, 'receiveHeadersEnd': 0.836}, 'protocol': 'h2', 'securityState': 'unknown'}, 'frameId': 'A2971702DE69F008914F18EAE6514DD5'}}
+    async def cb(request):
+        if request:
+            await tab.wait_request_loading(request, 5)
+            ok = 'Masonry PACKAGED' in (
+                await tab.get_response(request))['result']['body']
+            logger.warning(f'check wait_response callback, get_response {ok}')
+            assert ok
+        else:
+            raise ValueError
+
+    # listening response
+    def filter_function(r):
+        ok = 'www.python.org/static/js/libs/masonry.pkgd.min.js' in r['params'][
+            'response']['url']
+        return print('get response url:', r['params']['response']['url'],
+                     ok) or ok
+
+    task = asyncio.ensure_future(
+        tab.wait_response(
+            filter_function=filter_function, callback_function=cb, timeout=10),
+        loop=tab.loop)
+    await tab.click('#about>a')
+    await tab.wait_loading(2)
+    await task
+    # click download link, without wait_loading.
+    # request
+    # {'method': 'Network.responseReceived', 'params': {'requestId': '2FAFC4FC410A6DEDE88553B1836C530B', 'loaderId': '2FAFC4FC410A6DEDE88553B1836C530B', 'timestamp': 212239.182469, 'type': 'Document', 'response': {'url': 'https://www.python.org/downloads/', 'status': 200, 'statusText': '', 'headers': {'status': '200', 'server': 'nginx', 'content-type': 'text/html; charset=utf-8', 'x-frame-options': 'DENY', 'cache-control': 'max-age=604800, public', 'via': '1.1 vegur\n1.1 varnish\n1.1 varnish', 'accept-ranges': 'bytes', 'date': 'Sat, 05 Oct 2019 10:51:48 GMT', 'age': '282488', 'x-served-by': 'cache-iad2139-IAD, cache-hnd18720-HND', 'x-cache': 'MISS, HIT', 'x-cache-hits': '0, 119', 'x-timer': 'S1570272708.444646,VS0,VE0', 'content-length': '113779'}, 'mimeType': 'text/html', 'connectionReused': False, 'connectionId': 0, 'remoteIPAddress': '123.23.54.43', 'remotePort': 443, 'fromDiskCache': True, 'fromServiceWorker': False, 'fromPrefetchCache': False, 'encodedDataLength': 0, 'timing': {'requestTime': 212239.179388, 'proxyStart': -1, 'proxyEnd': -1, 'dnsStart': -1, 'dnsEnd': -1, 'connectStart': -1, 'connectEnd': -1, 'sslStart': -1, 'sslEnd': -1, 'workerStart': -1, 'workerReady': -1, 'sendStart': 0.392, 'sendEnd': 0.392, 'pushStart': 0, 'pushEnd': 0, 'receiveHeadersEnd': 0.975}, 'protocol': 'h2', 'securityState': 'secure', 'securityDetails': {'protocol': 'TLS 1.2', 'keyExchange': 'ECDHE_RSA', 'keyExchangeGroup': 'X25519', 'cipher': 'AES_128_GCM', 'certificateId': 0, 'subjectName': 'www.python.org', 'sanList': ['www.python.org', 'docs.python.org', 'bugs.python.org', 'wiki.python.org', 'hg.python.org', 'mail.python.org', 'pypi.python.org', 'packaging.python.org', 'login.python.org', 'discuss.python.org', 'us.pycon.org', 'pypi.io', 'docs.pypi.io', 'pypi.org', 'docs.pypi.org', 'donate.pypi.org', 'devguide.python.org', 'www.bugs.python.org', 'python.org'], 'issuer': 'DigiCert SHA2 Extended Validation Server CA', 'validFrom': 1537228800, 'validTo': 1602676800, 'signedCertificateTimestampList': [], 'certificateTransparencyCompliance': 'unknown'}}, 'frameId': '882CFDEEA07EB00A5E7510ADD2A39F22'}}
+    # response
+    # {'id': 30, 'result': {'body': '<!doctype html>\n<!--[if lt IE 7]>   <html class="no-js ie6 lt-ie...', 'base64Encoded': False}}
+
+
+async def test_tab_js_onload(tab: Tab):
+    # add js onload
+    js_id = await tab.add_js_onload(source='window.title=123456789')
+    assert js_id
+    await tab.set_url('http://p.3.cn')
+    assert (await tab.get_variable('window.title')) == 123456789
+    # remove js onload
+    assert await tab.remove_js_onload(js_id)
+    await tab.set_url('http://p.3.cn')
+    assert (await tab.get_variable('window.title')) != 123456789
+
+
+async def test_tab_current_html(tab: Tab):
+    html = await tab.get_html()
+    assert 'Customer name:' in html
+    # alias current_html
+    assert html == (await tab.current_html) == (await tab.html)
+
+
+async def test_tab_screenshot(tab: Tab):
+    # screenshot
+    screen = await tab.screenshot()
+    part = await tab.screenshot_element('fieldset')
+    assert screen
+    assert part
+    assert len(screen) > len(part)
+
+
+async def test_tab_set_ua_headers(tab: Tab):
+    # test set_ua
+    await tab.set_ua('Test UA')
+    # test set_headers
+    await tab.set_headers({'A': '1', 'B': '2'})
+    await tab.set_url('http://httpbin.org/get')
+    html = await tab.get_html()
+    assert '"A": "1"' in html and '"B": "2"' in html and '"User-Agent": "Test UA"' in html
+
+
+async def test_tab_keyboard_mouse(tab: Tab):
+    if 'httpbin.org/forms/post' not in (await tab.current_url):
+        await tab.set_url('http://httpbin.org/forms/post', timeout=5)
+    rect = await tab.get_bounding_client_rect('[type="email"]')
+    await tab.mouse_click(rect['left'], rect['top'], count=1)
+    await tab.keyboard_send(text='1')
+    await tab.keyboard_send(text='2')
+    await tab.keyboard_send(text='3')
+    await tab.mouse_click(rect['left'], rect['top'], count=2)
+    selection = await tab.get_variable('window.getSelection().toString()')
+    assert selection == '123'
+    # test mouse_drag_rel_chain draw a square, sometime witeboard load failed.....
+    await tab.set_url('https://zhoushuo.me/drawingborad/', timeout=5)
+    await tab.mouse_click(5, 5)
+    # drag with moving mouse, released on each `await`
+    walker = await tab.mouse_drag_rel_chain(320, 145).move(50, 0, 0.2).move(
+        0, 50, 0.2).move(-50, 0, 0.2).move(0, -50, 0.2)
+    await walker.move(50 * 1.414, 50 * 1.414, 0.2)
+
+
+async def test_examples():
+    async with AsyncChromeDaemon(host="127.0.0.1", port=port, max_deaths=1):
+        # ===================== Chrome Test Cases =====================
+        async with Chrome() as chrome:
+            await test_chrome(chrome)
+            # ===================== Tab Test Cases =====================
+            tab: Tab = await chrome.new_tab()
+            await test_tab_ws(tab)
+            # same as: async with tab.connect():
+            async with tab():
+                # test send raw message
+                await test_send_msg(tab)
+                # test cookies operations
+                await test_tab_cookies(tab)
+                # set url
+                await test_tab_set_url(tab)
+                # test js
+                await test_tab_js(tab)
+                # test wait_response
+                await test_wait_response(tab)
+                # test add_js_onload remove_js_onload
+                await test_tab_js_onload(tab)
+                # test set ua and set headers
+                await test_tab_set_ua_headers(tab)
+                # load url for other tests
+                await tab.set_url('http://httpbin.org/forms/post')
+                # test current_html
+                await test_tab_current_html(tab)
+                # test screenshot
+                await test_tab_screenshot(tab)
+                # test double click some positions. test keyboard_send input
+                await test_tab_keyboard_mouse(tab)
+                # clear cache
+                assert await tab.clear_browser_cache()
+                # close tab
+                await tab.close()
+            # close_browser gracefully, I have no more need of chrome instance
+            await chrome.close_browser()
+            # await chrome.kill()
+            sep = f'\n{"=" * 80}\n'
+            logger.critical(
+                f'{sep}Congratulations, all test cases passed.{sep}')
+
+
+if __name__ == "__main__":
+    loop = asyncio.get_event_loop()
+    loop.run_until_complete(test_examples())
diff --git a/examples/test_sync.py b/examples_sync.py
similarity index 94%
rename from examples/test_sync.py
rename to examples_sync.py
index 98e4bd1..ac07cc2 100644
--- a/examples/test_sync.py
+++ b/examples_sync.py
@@ -1,3 +1,8 @@
+import json
+import re
+
+from ichrome import Chrome, ChromeDaemon, logger
+
 """
 Test normal usage of ichrome.
 
@@ -19,15 +24,6 @@
 
 
 def test_example():
-    import sys
-    import os
-
-    # use local ichrome module
-    sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
-    os.chdir("..")  # for reuse exiting user data dir
-    from ichrome import Chrome, ChromeDaemon, logger
-    import re
-    import json
     """Example for crawling a special background request."""
 
     # reset default logger level, such as DEBUG
diff --git a/ichrome/__init__.py b/ichrome/__init__.py
index f2faa28..382a916 100644
--- a/ichrome/__init__.py
+++ b/ichrome/__init__.py
@@ -4,7 +4,7 @@
 from .base import Chrome, ChromeDaemon, Tab, Tag
 from .logs import logger
 
-__version__ = "1.1.3"
+__version__ = "1.1.4"
 __tips__ = "[github]: https://github.com/ClericPy/ichrome\n[cdp]: https://chromedevtools.github.io/devtools-protocol/\n[cmd args]: https://peter.sh/experiments/chromium-command-line-switches/"
 __all__ = [
     'Chrome', 'ChromeDaemon', 'Tab', 'Tag', 'AsyncChrome', 'AsyncTab', 'logger',
diff --git a/ichrome/__main__.py b/ichrome/__main__.py
index 930ec57..da047c1 100644
--- a/ichrome/__main__.py
+++ b/ichrome/__main__.py
@@ -20,7 +20,7 @@ def main():
     timeout=2
     """
     usage = '''
-    All the unknown args will be append to extra_config.
+    All the unknown args will be appended to extra_config.
 Demo:
     > python -m ichrome --host=127.0.0.1 --window-size=1212,1212 --incognito
     > ChromeDaemon cmd args: {'daemon': True, 'block': True, 'chrome_path': '', 'host': '127.0.0.1', 'port': 9222, 'headless': False, 'user_agent': '', 'proxy': '', 'user_data_dir': None, 'disable_image': False, 'start_url': 'about:blank', 'extra_config': ['--window-size=1212,1212', '--incognito'], 'max_deaths': 1, 'timeout': 2}
@@ -32,7 +32,7 @@ def main():
         help="show ichrome version info",
         action="store_true")
     parser.add_argument("-c", "--chrome_path", help="chrome_path", default="")
-    parser.add_argument("--host", help="host", default="localhost")
+    parser.add_argument("--host", help="host", default="127.0.0.1")
     parser.add_argument("-p", "--port", help="port", default=9222, type=int)
     parser.add_argument(
         "--headless", help="is_headless", default=False, action="store_true")
@@ -44,7 +44,7 @@ def main():
         "--disable_image", help="disable_image", action="store_true")
     parser.add_argument("--start_url", help="start_url", default="about:blank")
     parser.add_argument("--max_deaths", help="max_deaths", default=1, type=int)
-    parser.add_argument("--timeout", help="timeout", default=2, type=int)
+    parser.add_argument("--timeout", help="timeout", default=1, type=int)
     args, extra_config = parser.parse_known_args()
     if args.version:
         print(__version__)
diff --git a/ichrome/async_utils.py b/ichrome/async_utils.py
index 108f4ef..6d3fd32 100644
--- a/ichrome/async_utils.py
+++ b/ichrome/async_utils.py
@@ -20,7 +20,6 @@
 
 from .base import ChromeDaemon, Tag
 from .logs import logger
-
 """
 Async utils for connections and operations.
 [Recommended] Use daemon and async utils with different scripts.
@@ -44,6 +43,13 @@ def get_data_value(item, default=None, path: str = 'result.result.value'):
         return default
 
 
+def check_error(name, result, path='error.message', **kwargs):
+    error = get_data_value(result, path=path)
+    if error:
+        logger.info(f'{name} failed: {kwargs}. result: {result}')
+    return not error
+
+
 class AsyncChromeDaemon:
     __doc__ = ChromeDaemon.__doc__
 
@@ -229,10 +235,9 @@ async def close_browser(self):
 
     @property
     def status(self) -> str:
-        status = 'disconnected'
         if self.ws and not self.ws.closed:
-            status = 'connected'
-        return status
+            return 'connected'
+        return 'disconnected'
 
     def connect(self) -> _WSConnection:
         '''`async with tab.connect:`'''
@@ -689,10 +694,21 @@ async def set_ua(self,
             timeout=timeout)
         return data
 
+    async def goto_history(self, entryId: int = 0, timeout=None):
+        result = await self.send(
+            'Page.navigateToHistoryEntry', entryId=entryId, timeout=timeout)
+        return check_error('goto_history', result, entryId=entryId)
+
+    async def get_history_list(self, timeout=None) -> dict:
+        """return dict: {'currentIndex': 0, 'entries': [{'id': 1, 'url': 'about:blank', 'userTypedURL': 'about:blank', 'title': '', 'transitionType': 'auto_toplevel'}, {'id': 7, 'url': 'http://3.p.cn/', 'userTypedURL': 'http://3.p.cn/', 'title': 'Not Found', 'transitionType': 'typed'}, {'id': 9, 'url': 'http://p.3.cn/', 'userTypedURL': 'http://p.3.cn/', 'title': '', 'transitionType': 'typed'}]}}"""
+        result = await self.send('Page.getNavigationHistory', timeout=timeout)
+        return get_data_value(result, {}, path='result')
+
     async def set_url(self,
                       url: Optional[str] = None,
                       referrer: Optional[str] = None,
-                      timeout: Union[float, int] = None):
+                      timeout: Union[float, int] = None,
+                      timeout_stop_loading: bool = True):
         """
         Navigate the tab to the URL
         """
@@ -716,7 +732,8 @@ async def set_url(self,
             data = await self.send("Page.reload", timeout=timeout)
         time_passed = self.now - start_load_ts
         real_timeout = max((timeout - time_passed, 0))
-        await self.wait_loading(timeout=real_timeout, timeout_stop_loading=True)
+        await self.wait_loading(
+            timeout=real_timeout, timeout_stop_loading=timeout_stop_loading)
         return data
 
     async def js(self, javascript: str,
@@ -733,13 +750,21 @@ async def js(self, javascript: str,
         return await self.send(
             "Runtime.evaluate", timeout=timeout, expression=javascript)
 
-    async def querySelectorAll(
-            self,
-            cssselector: str,
-            index: Union[None, int, str] = None,
-            action: Union[None, str] = None,
-            timeout: Union[float, int] = None) -> Union[List[Tag], Tag, None]:
-        """CDP DOM domain is quite heavy both computationally and memory wise, use js instead.
+    async def handle_dialog(self, accept=True, promptText=None, timeout=None):
+        await self.enable('Page')
+        kwargs = {'timeout': timeout, 'accept': accept}
+        if promptText is not None:
+            kwargs['promptText'] = promptText
+        result = await self.send('Page.handleJavaScriptDialog', **kwargs)
+        return check_error(
+            'handle_dialog', result, accept=accept, promptText=promptText)
+
+    async def querySelectorAll(self,
+                               cssselector: str,
+                               index: Union[None, int, str] = None,
+                               action: Union[None, str] = None,
+                               timeout: Union[float, int] = None):
+        """CDP DOM domain is quite heavy both computationally and memory wise, use js instead. return List[Tag], Tag, None.
         If index is not None, will return the tag_list[index]
         else return the tag list.
         tab.querySelectorAll("#sc_hdu>li>a", index=2, action="removeAttribute('href')")
@@ -909,10 +934,19 @@ async def screenshot(self,
                 await f.write(b64decode(base64_img))
         return base64_img
 
-    async def add_js_onload(self, source, **kwargs):
-        '''Page.addScriptToEvaluateOnNewDocument'''
-        return await self.send(
+    async def add_js_onload(self, source: str, **kwargs) -> str:
+        '''Page.addScriptToEvaluateOnNewDocument, return the identifier [str].'''
+        data = await self.send(
             'Page.addScriptToEvaluateOnNewDocument', source=source, **kwargs)
+        return get_data_value(data, path='result.identifier') or ''
+
+    async def remove_js_onload(self, identifier: str, timeout=None):
+        '''Page.removeScriptToEvaluateOnNewDocument, return whether the identifier exist.'''
+        result = await self.send(
+            'Page.removeScriptToEvaluateOnNewDocument',
+            identifier=identifier,
+            timeout=timeout)
+        return check_error('remove_js_onload', result, identifier=identifier)
 
     async def get_value(self, name: str):
         """name or expression"""
@@ -938,13 +972,13 @@ async def get_page_size(self):
             "[window.innerWidth||document.documentElement.clientWidth||document.querySelector('body').clientWidth,window.innerHeight||document.documentElement.clientHeight||document.querySelector('body').clientHeight]"
         )
 
-    async def keyboard_send(self, type='char', timeout=None, **kwargs):
+    async def keyboard_send(self, *, type='char', timeout=None, **kwargs):
         '''type: keyDown, keyUp, rawKeyDown, char.
 
         kwargs:
             text, unmodifiedText, keyIdentifier, code, key...
 
-        https://chromedevtools.github.io/devtools-protocol/tot/Input#method-dispatchMouseEvent'''
+        https://chromedevtools.github.io/devtools-protocol/tot/Input/#method-dispatchKeyEvent'''
         return await self.send(
             'Input.dispatchKeyEvent', type=type, timeout=timeout, **kwargs)
 
diff --git a/ichrome/daemon.py b/ichrome/daemon.py
index 2a28250..435d205 100644
--- a/ichrome/daemon.py
+++ b/ichrome/daemon.py
@@ -66,7 +66,7 @@ def __init__(
             max_deaths=1,
             daemon=True,
             block=False,
-            timeout=2,
+            timeout=1,
             debug=False,
     ):
         if debug:
@@ -288,7 +288,11 @@ def run_forever(self, block=True, interval=5):
     def kill(self, force=False):
         self.ready = False
         if self.proc:
-            self.proc.kill()
+            self.proc.terminate()
+            try:
+                self.proc.wait(1)
+            except subprocess.TimeoutExpired:
+                self.proc.kill()
         if force:
             max_deaths = self.max_deaths
         else: