Get a list of all properties

Not a problem, let me see what I can do to help! Give this a shot and let me know if it works. Will need to run the Data Source so it has data, of course.
 

// This is highly dependent on where your DataSource lives. Assuming within the same Test Case.

// Assuming Data Source name of DataSource.
def DataSource = context.testCase.testSteps["DataSource"];

DataSource.getProperties().each {
 // testRunner should work, but it might need to be context.testCase.testSuite
 testRunner.testCase.testSuite.setPropertyValue( it.key, context.expand( '${DataSource#'+it.key+'}' ))
}

Thanks, that worked like a charm! Exactly what I needed.