feat(elements): Add isPresent() to ElementArrayFinder. (angular#3974)

lib/element.ts

@@ -428,6 +428,22 @@ export class ElementArrayFinder extends WebdriverWebElement {
         });
   }
 
+  /**
+   * Returns true if there are any elements present that match the finder.
+   *
+   * @alias element.all(locator).isPresent()
+   *
+   * @example
+   * expect($('.item').isPresent()).toBeTruthy();
+   *
+   * @returns {Promise<boolean>}
+   */
+  isPresent(): wdpromise.Promise<boolean> {
+    return this.count().then((count) => {
+      return count > 0;
+    });
+  }
+
   /**
    * Returns the most relevant locator.
    *

spec/basic/elements_spec.js

@@ -357,6 +357,13 @@ describe('ElementArrayFinder', function() {
     expect(element.all(by.binding('doesnotexist')).count()).toEqual(0);
   });
 
+  it('supports isPresent()', function() {
+    browser.get('index.html#/form');
+
+    expect(element.all(by.model('color')).isPresent()).toBeTruthy();
+    expect(element.all(by.binding('doesnotexist')).isPresent()).toBeFalsy();
+  });
+
   it('should return not present when an element disappears within an array',
       function() {
     browser.get('index.html#/form');