introduce setValueChangeEvent option

gradle/tests.gradle

@@ -32,7 +32,7 @@ task safari(type: Test) {
 task htmlunit(type: Test) {
   systemProperties['selenide.browser'] = 'htmlunit'
   include 'integration/**/*'
-  exclude 'com/codeborne/selenide/**/*'
+  exclude 'com/codeborne/selenide/**/*', 'integration/*PageWithoutJQuery*'
 }
 
 task phantomjs(type: Test) {

src/main/java/com/codeborne/selenide/Configuration.java

@@ -301,6 +301,18 @@ private static String getJenkinsReportsUrl() {
    */
   public static boolean versatileSetValue = Boolean.parseBoolean(System.getProperty("selenide.versatileSetValue", "false"));
 
+  /**
+   * If set to true, 'setValue' and 'val' methods of SelenideElement trigger changeEvent after main manipulations.
+   *
+   * Firing change event is not natural and could lead to unpredictable results. Browser fires this event automatically
+   * according to web driver actions. Recommended behaviour is to disable this option.
+   * Make its true by default for backward compatibility.
+   *
+   * Can be configured either programmatically or by system property "-Dselenide.setValueChangeEvent=true".
+   * Default value: true
+   */
+  public static boolean setValueChangeEvent = Boolean.parseBoolean(System.getProperty("selenide.setValueChangeEvent", "true"));
+
   /**
    * Choose how Selenide should retrieve web elements: using default CSS or Sizzle (CSS3)
    */

src/main/java/com/codeborne/selenide/commands/Append.java

@@ -5,14 +5,17 @@
 import com.codeborne.selenide.impl.WebElementSource;
 import org.openqa.selenium.WebElement;
 
+import static com.codeborne.selenide.Configuration.setValueChangeEvent;
 import static com.codeborne.selenide.impl.Events.events;
 
 public class Append implements Command<WebElement> {
   @Override
   public WebElement execute(SelenideElement proxy, WebElementSource locator, Object[] args) {
     WebElement input = locator.getWebElement();
     input.sendKeys((String) args[0]);
-    events.fireChangeEvent(input);
+    if (setValueChangeEvent) {
+      events.fireChangeEvent(input);
+    }
     return proxy;
   }
 }

src/main/java/com/codeborne/selenide/commands/SetValue.java

@@ -8,6 +8,7 @@
 import org.openqa.selenium.WebElement;
 
 import static com.codeborne.selenide.Configuration.fastSetValue;
+import static com.codeborne.selenide.Configuration.setValueChangeEvent;
 import static com.codeborne.selenide.Selenide.executeJavaScript;
 import static com.codeborne.selenide.impl.Events.events;
 
@@ -55,7 +56,9 @@ private void setValueForTextInput(WebElement element, String text) {
     } else {
       element.clear();
       element.sendKeys(text);
-      events.fireChangeEvent(element);
+      if (setValueChangeEvent) {
+        events.fireChangeEvent(element);
+      }
     }
   }
 

src/test/java/integration/PageWithJQuery.java

@@ -1,8 +1,10 @@
 package integration;
 
 import org.junit.Before;
+import org.junit.After;
 import org.junit.Test;
 import org.openqa.selenium.By;
+import com.codeborne.selenide.Configuration;
 
 import static com.codeborne.selenide.Condition.text;
 import static com.codeborne.selenide.Selenide.$;
@@ -24,9 +26,26 @@ public void setValueTriggersOnChangeEvent() {
     $("h2").shouldHave(text("john bon-jovi"));
   }
 
+  @Test
+  public void setValueDoesNotTriggerOnChangeEvent() {
+    Configuration.setValueChangeEvent = false;
+    $("#username").setValue("john");
+    $("h2").shouldNotHave(text("john"));
+
+    $("#username").append(" ");
+    $("#username").append("bon-jovi");
+
+    $("h2").shouldNotHave(text("john bon-jovi"));
+  }
+
   @Test
   public void selectByXpath() {
     $(By.xpath("html/body/div[2]/form[1]/fieldset[1]//input[@name='username']")).val("Underwood");
     $(By.xpath("/html//h2[1]")).shouldHave(text("Underwood"));
   }
+
+  @After
+  public void tearDown() {
+    Configuration.setValueChangeEvent = true;
+  }
 }

src/test/java/integration/PageWithoutJQuery.java

@@ -1,14 +1,16 @@
 package integration;
 
 import org.junit.Before;
+import org.junit.After;
 import org.junit.Test;
+import com.codeborne.selenide.Configuration;
 
 import static com.codeborne.selenide.Condition.text;
 import static com.codeborne.selenide.Selenide.$;
 
 public class PageWithoutJQuery extends IntegrationTest {
   @Before
-  public void openTestPageWithJQuery() {
+  public void openTestPageWithOutJQuery() {
     openFile("page_with_selects_without_jquery.html");
   }
 
@@ -22,4 +24,22 @@ public void setValueTriggersOnChangeEvent() {
 
     $("#username-mirror").shouldHave(text("john bon-jovi"));
   }
+
+  @Test
+  public void setValueDoesNotTriggerOnChangeEvent() {
+    Configuration.setValueChangeEvent = false;
+
+    $("#username").setValue("john");
+    $("#username-mirror").shouldHave(text("_"));
+
+    $("#username").append(" ");
+    $("#username").append("bon-jovi");
+
+    $("#username-mirror").shouldHave(text("_"));
+  }
+
+  @After
+  public void tearDown() {
+    Configuration.setValueChangeEvent = true;
+  }
 }