The Tester tests an argument or set of arguments for a feature, and then routes that feature through either a PASSED or FAILED port depending on the results of the test(s).
The arguments to test can include two attributes (for example, attribute1 = attribute2?) or one attribute and one constant (for example, attribute1 != 10?).
The Pass Criteria setting can be 'One Test (OR)' or 'All Tests (AND)' or a 'Composite test' i.e. where Attr1 is equal to 10 or Attr1 is equal to 20, and Attr2 is not equal to 999
The attached workspace shows an example use of the Tester transformer.
In this example parks are tested according to an area attribute - there are examples of AND and OR and COMPOSITE tests.