code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.javascript;
  
  import static org.junit.jupiter.api.Assertions.fail;
  import static org.openqa.selenium.testing.TestUtilities.isOnTravis;
  
  import com.google.common.base.Stopwatch;
  import java.net.URL;
  import java.util.concurrent.TimeUnit;
  import java.util.function.Function;
  import java.util.function.Supplier;
  import java.util.logging.Logger;
  import org.openqa.selenium.JavascriptExecutor;
  import org.openqa.selenium.OutputType;
  import org.openqa.selenium.TakesScreenshot;
  import org.openqa.selenium.WebDriver;
  import org.openqa.selenium.WebDriverException;
  
  class ClosureTestStatement {
  
    private static final Logger LOG = Logger.getLogger(ClosureTestStatement.class.getName());
  
    private final Supplier<WebDriver> driverSupplier;
    private final String testPath;
    private final Function<String, URL> filePathToUrlFn;
    private final long timeoutSeconds;
  
    public ClosureTestStatement(
        Supplier<WebDriver> driverSupplier,
        String testPath,
        Function<String, URL> filePathToUrlFn,
        long timeoutSeconds) {
      this.driverSupplier = driverSupplier;
      this.testPath = testPath;
      this.filePathToUrlFn = filePathToUrlFn;
      this.timeoutSeconds = Math.max(0, timeoutSeconds);
    }
  
    public void evaluate() throws Throwable {
      URL testUrl = filePathToUrlFn.apply(testPath);
      LOG.info("Running: " + testUrl);
  
      Stopwatch stopwatch = Stopwatch.createStarted();
  
      WebDriver driver = driverSupplier.get();
  
      if (!isOnTravis()) {
        // Attempt to make the window as big as possible.
        try {
          driver.manage().window().maximize();
        } catch (RuntimeException ignored) {
          // We tried.
        }
      }
  
      JavascriptExecutor executor = (JavascriptExecutor) driver;
      // Avoid Safari JS leak between tests.
      executor.executeScript("if (window && window.top) window.top.G_testRunner = null");
  
      try {
        driver.get(testUrl.toString());
      } catch (WebDriverException e) {
        fail("Test failed to load: " + e.getMessage());
      }
  
      while (!getBoolean(executor, Query.IS_FINISHED)) {
        long elapsedTime = stopwatch.elapsed(TimeUnit.SECONDS);
        if (timeoutSeconds > 0 && elapsedTime > timeoutSeconds) {
          throw new JavaScriptAssertionError(
              "Tests timed out after "
                  + elapsedTime
                  + " s. \nCaptured Errors: "
                  + ((JavascriptExecutor) driver).executeScript("return window.errors;")
                  + "\nPageSource: "
                  + driver.getPageSource()
                  + "\nScreenshot: "
                  + ((TakesScreenshot) driver).getScreenshotAs(OutputType.BASE64));
        }
        TimeUnit.MILLISECONDS.sleep(100);
      }
  
      if (!getBoolean(executor, Query.IS_SUCCESS)) {
        String report = getString(executor, Query.GET_REPORT);
        throw new JavaScriptAssertionError(report);
      }
    }
  
    private boolean getBoolean(JavascriptExecutor executor, Query query) {
      return (Boolean) executor.executeScript(query.script);
    }
  
    private String getString(JavascriptExecutor executor, Query query) {
      return (String) executor.executeScript(query.script);
    }
  
    private enum Query {
      IS_FINISHED("return !!tr && tr.isFinished();"),
      IS_SUCCESS("return !!tr && tr.isSuccess();"),
      GET_REPORT("return tr.getReport(true);");
  
      private final String script;
  
      Query(String script) {
        this.script = "var tr = window.top.G_testRunner;" + script;
      }
    }
  }
  