MDL-50940 behat: Added ability to check field value by xpath

lib/tests/behat/behat_forms.php

@@ -212,6 +212,31 @@ class behat_forms extends behat_base {
         }
     }
 
+    /**
+     * Checks, the field matches the value. More info in http://docs.moodle.org/dev/Acceptance_testing#Providing_values_to_steps.
+     *
+     * @Then /^the field with xpath "(?P<fieldxpath_string>(?:[^"]|\\")*)" matches value "(?P<field_value_string>(?:[^"]|\\")*)"$/
+     * @throws ElementNotFoundException Thrown by behat_base::find
+     * @param string $fieldxpath
+     * @param string $value
+     * @return void
+     */
+    public function the_field_with_xpath_matches_value($fieldxpath, $value) {
+
+        // Get the field.
+        $fieldnode = $this->find('xpath', $fieldxpath);
+        $formfield = behat_field_manager::get_form_field($fieldnode, $this->getSession());
+
+        // Checks if the provided value matches the current field value.
+        if (!$formfield->matches($value)) {
+            $fieldvalue = $formfield->get_value();
+            throw new ExpectationException(
+                'The \'' . $fieldxpath . '\' value is \'' . $fieldvalue . '\', \'' . $value . '\' expected' ,
+                $this->getSession()
+            );
+        }
+    }
+
     /**
      * Checks, the field does not match the value. More info in http://docs.moodle.org/dev/Acceptance_testing#Providing_values_to_steps.
      *