Set Element Attribute keyword added

Author: Jani Mikkonen

README.md

@@ -159,6 +159,10 @@ tests do show they work.
 
   * Returns a dict of default capabilties. Useful if you need to construct desired_capabilities and you dont need to remember all basic things you need to have. This is due to SeleniumLibrary not providing those defaults anymore if user provide their own.
 
+* Set Element Attribute   **locator**  **attribute_name** **value**
+
+  * Sets arbituary attribute of the element into provided value
+
 # Keyword Documentation
 
 Keyword documentation [here](https://salabs.github.io/robotframework-seleniumtestability/index.html) and if you need to create one for offline usage:

assets/templates/index.html

@@ -124,7 +124,7 @@
       </table>
       <div id="container">
         <div id="navi"><button id="hiddenbutton">Should be overlayed</button></div>
-        <div id="infoi">
+        <div id="infoi" random_attribute="yey">
           <img src="http://placehold.it/100x100" height="100" width="100" />
         </div>
     </div>

atest/attributes.robot

@@ -0,0 +1,26 @@
+*** Settings ***
+Documentation   Verifies webelement attribute getters/setters
+Suite Setup     Start Flask App
+Suite Teardown  Stop Flask App
+Test Teardown   Teardown Web Environment
+Test Template   Show And Hide Test
+Library         SeleniumLibrary  plugins=${CURDIR}/../src/SeleniumTestability;True;29 seconds;False
+Resource        keywords.robot
+
+*** Test Cases ***
+Set Attribute In Firefox
+  ${FF}  ${URL}
+
+Set Attribute In Chrome
+  ${GC}  ${URL}
+
+*** Keywords ***
+Show And Hide Test
+  [Arguments]  ${BROWSER}  ${URL}
+  [Documentation]  Verifies Set Element Attribute
+  Setup Web Environment  ${BROWSER}  ${URL}
+  ${x}=  Get Element Attribute  id:infoi  random_attribute
+  Should Be Equal   ${x}  yey
+  Set Element Attribute   id:infoi  random_attribute  NAY!
+  ${x}=  Get Element Attribute  id:infoi    random_attribute
+  Should Be Equal   ${x}  NAY!

src/SeleniumTestability/javascript.py

@@ -40,4 +40,7 @@
     "get_element_at": """
         return document.elementFromPoint(arguments[0], arguments[1])
     """,
+    "set_element_attribute": """
+        arguments[0].setAttribute(arguments[1], arguments[2])
+    """,
 }

src/SeleniumTestability/plugin.py

@@ -533,3 +533,13 @@ def get_default_capabilities(self: "SeleniumTestability", browser_name: str) ->
         except Exception as e:
             self.logger.debug(e)
             return None
+
+
+    @log_wrapper
+    @keyword
+    def set_element_attribute(self: "SeleniumTestability", locator: LocatorType, attribute: str, value: str) -> None:
+        """
+        Sets ``locator`` attribute ``attribute`` to ``value``
+        """
+        from_element = self.el.find_element(locator)
+        self.ctx.driver.execute_script(JS_LOOKUP["set_element_attribute"], from_element, attribute, value)