How to manage same selenium test for multiple user role - selenium

Question

I have been developing a selenium/Java-based test automation in my company as a beginner. I am using the page object model and TestNG testing framework. Till now I have written test scripts with respect to the user (role: admin). Now I have to test the application functionality based on different users type e.g technician, support team, service assistance, and so on.
Some users have the same permissions in the application as admin users. E.g Test case: create an invoice (service assistance and service advisors also have permission to create invoices as admin). Test case script for creation of invoice I have already created but I don't want to create the same script again and again for each user role. So I want some suggestions on how can I manage this type of situation. If someone provides some documentation, or project example it will be great help for me. Also, I want to know how can I manage these types of test cases in different test suits.
I thought of some of the solutions:
Adding user role parameter in each test case/class
using TestNg Groups

Answer 1

You might do it in a next way:
1 Add role parameter to your test configuration when you authorize the user. It might be e.g #BeforeTest method. Annotate your method with #Parameter, and also set the value in testng.xml.
This tutorial may help:
https://www.toolsqa.com/testng/testng-parameters/
2 Create several TestNG xml suites. For a big project, I suggest creating a separate suite.xml per user role with all the test classes and packages you need. Then you'll be able to create the main TestNG xml and refer to other xmls with suite-file.
See https://stackoverflow.com/a/31851469/5226491
You can organize the suite to stay using a single xml, it depends on what you prefer.
How to group tests
I suggest do not mix test methods for multiple roles within a single class. Try to split them into separate classes.
This suggestion induces to keep test structure simple.
The main idea:
define the role before the test class run, and do not switch it when the class run is in progress.
Let's imagine:
you have roles A, B, C.
and test methods: method1Test, ...method7Test.
And
method1Test, method2Test, method3Test work for all roles.
method4Test, method5Test work for all roles A, B
method6Test, method7Test work for all roles B, C
So, this suggests to split this methods on 3 classes:
Class1Test with method1Test, method2Test, method3Test
Class2Test with method4Test, method5Test
Class3Test with method6Test, method7Test
Eventually, you'll have the ability to define the classes used per a unique role, and also to reuse some classes for multiple roles.
Example for single TestNG xml file.
<suite name="test-suite">
<test name="roleA-suite">
<parameter name="roleName" value="roleA"/>
<classes>
<class name="Class1Test"/>
<class name="Class2Test"/>
</classes>
</test>
<test name="roleB-suite">
<parameter name="roleName" value="roleB"/>
<classes>
<class name="Class1Test"/>
<class name="Class2Test"/>
<class name="Class3Test"/>
</classes>
</test>
<test name="roleC-suite">
<parameter name="roleName" value="roleC"/>
<classes>
<class name="Class1Test"/>
<class name="Class3Test"/>
</classes>
</test>
</suite>
Using Groups
It's also possible for this task, but I personally don't like using groups, IMHO they introduce a lot of complexity and it might be not easy to combine this with other TestNG features, e.g. with setting priority on tests, or with the depends-on feature. So maybe other users will share the positive experience using groups.
Anyway, you might try to use a groups approach and choose the best, you like.
Look at this tutorial:
https://www.lambdatest.com/blog/grouping-test-cases-in-testng/