Upgrade to Selenium 4 and use CDP for Performance metrics (#233)

Co-authored-by: Carlos Kidman <carlos@qap.dev>

pylenium/cdp.py

@@ -0,0 +1,58 @@
+""" Chrome DevTools Protocol (CDP) introduced in Selenium 4.
+
+Resources:
+    - https://www.selenium.dev/documentation/webdriver/bidirectional/chrome_devtools/
+    - https://chromedevtools.github.io/devtools-protocol/
+
+* Currently only supports the Chrome Browser, although some chromium browsers may work as well.
+"""
+
+from typing import Dict
+
+
+class CDP:
+    """Chrome DevTools Protocol."""
+
+    def __init__(self, webdriver):
+        self._webdriver = webdriver
+
+    def execute_command(self, cmd: str, cmd_args: Dict) -> Dict:
+        """Execute Chrome Devtools Protocol command and get returned result.
+
+        The command and command args should follow chrome devtools protocol domains/commands, refer to link
+        https://chromedevtools.github.io/devtools-protocol/
+
+        Args:
+            cmd: The command name
+            cmd_args: The command args. Pass an empty dict {} if there is no command args
+
+        Examples:
+            py.cdp.execute_command('Network.getResponseBody', {'requestId': requestId})
+
+        Returns:
+            A dict of results or an empty dict {} if there is no result to return.
+            For example, to getResponseBody:
+            {'base64Encoded': False, 'body': 'response body string'}
+        """
+        return self._webdriver.execute_cdp_cmd(cmd, cmd_args)
+
+    def get_performance_metrics(self) -> Dict:
+        """Get performance metrics from Chrome DevTools - similar to the Performance tab in Chrome.
+
+        Examples:
+            metrics = py.cdp.get_performance_metrics()
+
+        Returns:
+            A dict of performance metrics including 'ScriptDuration', 'ThreadTime', 'ProcessTime', and 'DomContentLoaded'.
+
+            {'metrics': [
+                {'name': 'Timestamp', 'value': 425608.80694},
+                {'name': 'AudioHandlers', 'value': 0},
+                {'name': 'ThreadTime', 'value': 0.002074},
+                ...
+                ]
+            }
+        """
+        # The commented out code below should have been executed prior to this function call.
+        # self._webdriver.execute_cdp_cmd("Performance.enable", {})
+        return self._webdriver.execute_cdp_cmd("Performance.getMetrics", {})

pylenium/driver.py

@@ -11,6 +11,7 @@
 from selenium.webdriver.support import expected_conditions as ec
 
 from pylenium import webdriver_factory
+from pylenium.cdp import CDP
 from pylenium.config import PyleniumConfig
 from pylenium.element import Element, Elements
 from pylenium.performance import Performance
@@ -236,6 +237,11 @@ def performance(self) -> Performance:
         """The Pylenium Performance API."""
         return Performance(self.webdriver)
 
+    @property
+    def cdp(self) -> CDP:
+        """The Chrome DevTools Protocol API."""
+        return CDP(self.webdriver)
+
     def title(self) -> str:
         """The current page's title."""
         self.log.info("[STEP] py.title() - Get the current page title")

pylenium/webdriver_factory.py

@@ -2,6 +2,7 @@
 from typing import List, Optional
 
 from selenium import webdriver
+from selenium.webdriver import Chrome
 from selenium.webdriver.remote.webdriver import WebDriver
 from selenium.webdriver.chrome.service import Service as ChromeService
 from selenium.webdriver.edge.service import Service as EdgeService
@@ -178,7 +179,7 @@ def build_chrome(
     extension_paths: Optional[List[str]],
     local_path: Optional[str],
     webdriver_kwargs: Optional[dict],
-) -> WebDriver:
+) -> Chrome:
     """Build a ChromeDriver.
 
     Args:
@@ -194,12 +195,18 @@ def build_chrome(
     """
     options = build_options(Browser.CHROME, browser_options, experimental_options, extension_paths)
     if local_path:
-        return webdriver.Chrome(service=ChromeService(local_path), options=options, **(webdriver_kwargs or {}))
-    return webdriver.Chrome(
-        service=ChromeService(ChromeDriverManager(version=version).install()),
-        options=options,
-        **(webdriver_kwargs or {}),
-    )
+        driver = webdriver.Chrome(service=ChromeService(local_path), options=options, **(webdriver_kwargs or {}))
+    else:
+        driver = webdriver.Chrome(
+            service=ChromeService(ChromeDriverManager(version=version).install()),
+            options=options,
+            **(webdriver_kwargs or {}),
+        )
+
+    # enable Performance Metrics from Chrome Dev Tools
+    driver.execute_cdp_cmd("Performance.enable", {})
+
+    return driver
 
 
 def build_edge(

pyproject.toml

@@ -18,7 +18,7 @@ pytest-xdist = "^2.2.0"
 pytest-parallel = "^0.1.0"
 axe-selenium-python = "^2.1.6"
 Faker = "^8.2.1"
-selenium = "4.0.0"
+selenium = "4.1.0"
 
 [tool.poetry.dev-dependencies]
 black = "^21.5b1"

tests/performance/test_cdp_performance.py

@@ -0,0 +1,10 @@
+""" Chrome DevTools Protocol - Performance Tab """
+from pylenium.driver import Pylenium
+
+
+def test_capture_performance_metrics(py: Pylenium):
+    py.visit("https://qap.dev")
+    metrics = py.cdp.get_performance_metrics()
+    assert metrics["metrics"]
+    assert metrics["metrics"][0]["name"] == "Timestamp"
+    assert metrics["metrics"][0]["value"] > 0

tests/test_flows.py

@@ -1,21 +1,28 @@
+import pytest
+from pylenium.driver import Pylenium
 
-def test_add_to_cart(py):
-    py.visit('https://jane.com')
-    py.get('[data-testid="deal-image"]').click()
 
-    for dropdown in py.find('select'):
-        dropdown.select(1)
+@pytest.fixture
+def sauce(py: Pylenium) -> Pylenium:
+    """Login to saucedemo.com as standard user."""
+    py.visit("https://www.saucedemo.com/")
+    py.get("#user-name").type("standard_user")
+    py.get("#password").type("secret_sauce")
+    py.get("#login-button").click()
+    yield py
+    py.get("#react-burger-menu-btn").click()
+    py.get("#logout_sidebar_link").should().be_visible().click()
 
-    py.get('[data-testid="add-to-bag"]', timeout=1).click()
-    assert py.contains("$00.11")
 
+def test_add_to_cart_css(sauce: Pylenium):
+    """Add an item to the cart. The number badge on the cart icon should increment as expected."""
+    sauce.get("[id*='add-to-cart']").click()
+    assert sauce.get("a.shopping_cart_link").should().have_text("1")
 
-def test_add_to_cart_xpath(py):
-    py.visit('https://jane.com')
-    py.getx('//*[@data-testid="deal-image"]').click()
 
-    for dropdown in py.findx('//select'):
-        dropdown.select(1)
-
-    py.getx('//*[@data-testid="add-to-bag"]', timeout=1).click()
-    assert py.contains("$00.11")
+def test_add_to_cart_xpath(sauce: Pylenium):
+    """Add 6 different items to the cart. There should be 6 items in the cart."""
+    for button in sauce.findx("//*[contains(@id, 'add-to-cart')]"):
+        button.click()
+    sauce.getx("//a[@class='shopping_cart_link']").click()
+    assert sauce.findx("//*[@class='cart_item']").should().have_length(6)

tests/ui/test_element.py

@@ -122,9 +122,10 @@ def test_element_property(py: Pylenium):
 
 
 def test_element_should_disappear(py: Pylenium):
-    spinner = "#serverSideDataTable_processing"
-    py.visit("https://www.copart.com/lotSearchResults/?free=true&query=nissan")
-    assert py.get(spinner).should().disappear()
+    py.visit(f"{THE_INTERNET}/dynamic_loading/1")
+    py.get("#start > button").click()
+    assert py.get("#loading").should().disappear()
+    assert py.get("#finish").should().have_text("Hello World!")
 
 
 def test_element_has_attribute(py: Pylenium):