A testing approach for XML schemas

XML is a language frequently used for data representation and interchange in Web-based applications. In most cases, the XML documents must conform to a schema that defines the type of data that is accepted by a Web application. In this sense, an error in the schema or in the XML document can lead to failures in the application; the use of testing approaches, criteria and specific tools to ensure the reliability of data in the XML format is fundamental. We present a testing approach that helps to reveal faults in XML schemas. The test process involves generating XML documents with some modifications with respect to the original XML document and using queries to these documents to validate the schema. The XML documents and queries are generated according to a set of fault classes defined for the XML schemas. A case study applying the proposed approach is described and the results are presented.