microsoft · mxschmitt · Aug 10, 2020 · Aug 8, 2020 · Aug 10, 2020
diff --git a/README.md b/README.md
@@ -1,6 +1,6 @@
 # 🎭 [Playwright](https://github.com/microsoft/playwright) for Python
 
-[![PyPI version](https://badge.fury.io/py/playwright.svg)](https://pypi.python.org/pypi/playwright/) [![Join Slack](https://img.shields.io/badge/join-slack-infomational)](https://join.slack.com/t/playwright/shared_invite/enQtOTEyMTUxMzgxMjIwLThjMDUxZmIyNTRiMTJjNjIyMzdmZDA3MTQxZWUwZTFjZjQwNGYxZGM5MzRmNzZlMWI5ZWUyOTkzMjE5Njg1NDg) <!-- GEN:chromium-version-badge -->[![Chromium version](https://img.shields.io/badge/chromium-86.0.4217.0-blue.svg?logo=google-chrome)](https://www.chromium.org/Home)<!-- GEN:stop --> <!-- GEN:firefox-version-badge -->[![Firefox version](https://img.shields.io/badge/firefox-78.0b5-blue.svg?logo=mozilla-firefox)](https://www.mozilla.org/en-US/firefox/new/)<!-- GEN:stop --> [![WebKit version](https://img.shields.io/badge/webkit-14.0-blue.svg?logo=safari)](https://webkit.org/)
+[![PyPI version](https://badge.fury.io/py/playwright.svg)](https://pypi.python.org/pypi/playwright/) [![Join Slack](https://img.shields.io/badge/join-slack-infomational)](https://join.slack.com/t/playwright/shared_invite/enQtOTEyMTUxMzgxMjIwLThjMDUxZmIyNTRiMTJjNjIyMzdmZDA3MTQxZWUwZTFjZjQwNGYxZGM5MzRmNzZlMWI5ZWUyOTkzMjE5Njg1NDg) <!-- GEN:chromium-version-badge -->[![Chromium version](https://img.shields.io/badge/chromium-86.0.4217.0-blue.svg?logo=google-chrome)](https://www.chromium.org/Home)<!-- GEN:stop --> <!-- GEN:firefox-version-badge -->[![Firefox version](https://img.shields.io/badge/firefox-79.0a1-blue.svg?logo=mozilla-firefox)](https://www.mozilla.org/en-US/firefox/new/)<!-- GEN:stop --> [![WebKit version](https://img.shields.io/badge/webkit-14.0-blue.svg?logo=safari)](https://webkit.org/)
 
 ##### [Docs](#documentation) | [API reference](https://github.com/microsoft/playwright/blob/master/docs/api.md)
 
@@ -10,7 +10,7 @@ Playwright is a Python library to automate [Chromium](https://www.chromium.org/H
 |   :---   | :---: | :---: | :---:   |
 | Chromium <!-- GEN:chromium-version -->86.0.4217.0<!-- GEN:stop --> | ✅ | ✅ | ✅ |
 | WebKit 14.0 | ✅ | ✅ | ✅ |
-| Firefox <!-- GEN:firefox-version -->78.0b5<!-- GEN:stop --> | ✅ | ✅ | ✅ |
+| Firefox <!-- GEN:firefox-version -->79.0a1<!-- GEN:stop --> | ✅ | ✅ | ✅ |
 
 Headless execution is supported for all the browsers on all platforms.
 

diff --git a/api.json b/api.json
diff --git a/driver/package.json b/driver/package.json
@@ -13,7 +13,7 @@
   },
   "license": "Apache-2.0",
   "dependencies": {
-    "playwright": "1.3.0-next.1596659749397"
+    "playwright": "1.3.0-next.1596843106133"
   },
   "devDependencies": {
     "pkg": "^4.4.9"

diff --git a/playwright/async_api.py b/playwright/async_api.py
@@ -944,7 +944,7 @@ async def hover(
     ) -> NoneType:
         """ElementHandle.hover
 
-        This method scrolls element into view if needed, and then uses page.mouse to hover over the center of the element.
+        This method waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to hover over the center of the element.
         If the element is detached from DOM, the method throws an error.
 
         Parameters
@@ -979,7 +979,7 @@ async def click(
     ) -> NoneType:
         """ElementHandle.click
 
-        This method scrolls element into view if needed, and then uses page.mouse to click in the center of the element.
+        This method waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to click in the center of the element.
         If the element is detached from DOM, the method throws an error.
 
         Parameters
@@ -1028,7 +1028,7 @@ async def dblclick(
     ) -> NoneType:
         """ElementHandle.dblclick
 
-        This method scrolls element into view if needed, and then uses page.mouse to click in the center of the element.
+        This method waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to double click in the center of the element.
         If the element is detached from DOM, the method throws an error.
         Bear in mind that if the first click of the `dblclick()` triggers a navigation event, there will be an exception.
 
@@ -1241,7 +1241,7 @@ async def check(
     ) -> NoneType:
         """ElementHandle.check
 
-        If element is not already checked, it scrolls it into view if needed, and then uses elementHandle.click to click in the center of the element.
+        This method waits for actionability checks. Then, if the element is not already checked, this method scrolls the element into view and uses elementHandle.click to click in the center of the element.
 
         Parameters
         ----------
@@ -1263,7 +1263,7 @@ async def uncheck(
     ) -> NoneType:
         """ElementHandle.uncheck
 
-        If element is not already unchecked, it scrolls it into view if needed, and then uses elementHandle.click to click in the center of the element.
+        This method waits for actionability checks. Then, if the element is not already unchecked, this method scrolls the element into view and uses elementHandle.click to click in the center of the element.
 
         Parameters
         ----------
@@ -2108,7 +2108,7 @@ async def click(
     ) -> NoneType:
         """Frame.click
 
-        This method fetches an element with `selector`, scrolls it into view if needed, and then uses page.mouse to click in the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to click in the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
 
         Parameters
@@ -2160,7 +2160,7 @@ async def dblclick(
     ) -> NoneType:
         """Frame.dblclick
 
-        This method fetches an element with `selector`, scrolls it into view if needed, and then uses page.mouse to double click in the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to double click in the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
         Bear in mind that if the first click of the `dblclick()` triggers a navigation event, there will be an exception.
 
@@ -2339,7 +2339,7 @@ async def hover(
     ) -> NoneType:
         """Frame.hover
 
-        This method fetches an element with `selector`, scrolls it into view if needed, and then uses page.mouse to hover over the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to hover over the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
 
         Parameters
@@ -2529,7 +2529,7 @@ async def check(
     ) -> NoneType:
         """Frame.check
 
-        This method fetches an element with `selector`, if element is not already checked, it scrolls it into view if needed, and then uses frame.click to click in the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks. Then, if the element is not already checked, this method scrolls the element into view and uses elementHandle.click to click in the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
 
         Parameters
@@ -2558,7 +2558,7 @@ async def uncheck(
     ) -> NoneType:
         """Frame.uncheck
 
-        This method fetches an element with `selector`, if element is not already unchecked, it scrolls it into view if needed, and then uses frame.click to click in the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks. Then, if the element is not already unchecked, this method scrolls the element into view and uses elementHandle.click to click in the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
 
         Parameters
@@ -4068,7 +4068,7 @@ async def click(
     ) -> NoneType:
         """Page.click
 
-        This method fetches an element with `selector`, scrolls it into view if needed, and then uses page.mouse to click in the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to click in the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
         Shortcut for page.mainFrame().click(selector[, options]).
 
@@ -4121,7 +4121,7 @@ async def dblclick(
     ) -> NoneType:
         """Page.dblclick
 
-        This method fetches an element with `selector`, scrolls it into view if needed, and then uses page.mouse to double click in the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to double click in the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
         Bear in mind that if the first click of the `dblclick()` triggers a navigation event, there will be an exception.
 
@@ -4304,7 +4304,7 @@ async def hover(
     ) -> NoneType:
         """Page.hover
 
-        This method fetches an element with `selector`, scrolls it into view if needed, and then uses page.mouse to hover over the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks, then scrolls the element into view if needed and uses page.mouse to hover over the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
         Shortcut for page.mainFrame().hover(selector[, options]).
 
@@ -4494,7 +4494,7 @@ async def check(
     ) -> NoneType:
         """Page.check
 
-        This method fetches an element with `selector`, if element is not already checked, it scrolls it into view if needed, and then uses page.click to click in the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks. Then, if the element is not already checked, this method scrolls the element into view and uses elementHandle.click to click in the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
         Shortcut for page.mainFrame().check(selector[, options]).
 
@@ -4524,7 +4524,7 @@ async def uncheck(
     ) -> NoneType:
         """Page.uncheck
 
-        This method fetches an element with `selector`, if element is not already unchecked, it scrolls it into view if needed, and then uses page.click to click in the center of the element.
+        This method waits for an element matching `selector`, waits for actionability checks. Then, if the element is not already unchecked, this method scrolls the element into view and uses elementHandle.click to click in the center of the element.
         If there's no element matching `selector`, the method waits until a matching element appears in the DOM. If the element is detached during the actionability checks, the action is retried.
         Shortcut for page.mainFrame().uncheck(selector[, options]).
 
@@ -4574,7 +4574,7 @@ async def waitForFunction(
         The `waitForFunction` can be used to observe viewport size change:
 
         To pass an argument from Node.js to the predicate of `page.waitForFunction` function:
-        Shortcut for [page.mainFrame().waitForFunction(pageFunction, arg, options]])](#framewaitforfunctionpagefunction-arg-options).
+        Shortcut for page.mainFrame().waitForFunction(pageFunction[, arg, options]).
 
         Parameters
         ----------

diff --git a/playwright/drivers/browsers.json b/playwright/drivers/browsers.json
@@ -8,7 +8,7 @@
     },
     {
       "name": "firefox",
-      "revision": "1144",
+      "revision": "1154",
       "download": true
     },
     {

diff --git a/playwright/page.py b/playwright/page.py
@@ -539,8 +539,15 @@ async def screenshot(
         fullPage: bool = None,
         clip: FloatRect = None,
     ) -> bytes:
-        binary = await self._channel.send("screenshot", locals_to_params(locals()))
-        return base64.b64decode(binary)
+        params = locals_to_params(locals())
+        if "path" in params:
+            del params["path"]
+        encoded_binary = await self._channel.send("screenshot", params)
+        decoded_binary = base64.b64decode(encoded_binary)
+        if path:
+            with open(path, "wb") as fd:
+                fd.write(decoded_binary)
+        return decoded_binary
 
     async def title(self) -> str:
         return await self._main_frame.title()
@@ -722,7 +729,8 @@ async def pdf(
         path: str = None,
     ) -> bytes:
         params = locals_to_params(locals())
-        del params["path"]
+        if "path" in params:
+            del params["path"]
         encoded_binary = await self._channel.send("pdf", params)
         decoded_binary = base64.b64decode(encoded_binary)
         if path: