A Testing Approach for XML Schemas

2011 IEEE 27th International Conference on Data Engineering, 2011

Abstract. The knowledge of XML schema of XML documents is a crucial aspect to ensure that we work with correct data, as well as a key optimization approach to XML data processing. In this paper we provide an overview of research topics related to XML schemas that we have been dealing with during our work on Information Society Project (1ET100300419).

Information Systems, 2011

We consider the determinism checking of XML Schema content models, as required by the W3C Recommendation. We argue that currently applied solutions have flaws and make processors vulnerable to exponential resource needs by pathological schemas, and we help to eliminate this potential vulnerability of XML Schema based systems. XML Schema content models are essentially regular expressions extended with numeric occurrence indicators. A previously published polynomial-time solution to check the determinism of such expressions is improved to run in linear time, and the improved algorithm is implemented and evaluated experimentally. When compared to the corresponding method of a popular production-quality XML Schema processor, the new implementation runs orders of magnitude faster. Enhancing the solution to take further extensions of XML Schema into account without compromising its linear scalability is also discussed.

In this paper, we propose new models and algorithms to perform practical computations on W3C XML Schemas, which are schema minimization, schema equivalence testing, subschema testing and subschema extraction. We have conducted experiments on an e-commerce standard XSD called xCBL to demonstrate the e?ectiveness of our algorithms. One experiment has refuted the claim that the xCBL 3.5 XSD is compatible with the xCBL 3.0 XSD. Another experiment has shown that the xCBL XSDs can be effectively trimmed into small subschemas for specific applications, which has significantly reduced schema processing time.

2007 29th International Conference on Information Technology Interfaces, 2007

Assuring quality IT solutions demands assuring quality in all aspects of software development process. For this we need well-formed methods with suitable metrics with which we can verify if a process, software product, software component, software artifact or other part of possible solution meets defined quality characteristics. XML Schemas and corresponding XML documents are becoming the most important software artifacts. Today we can find large number of software metrics which are mostly used for software products. Very little has been done in field of metrics for XML Schema specification, especially metrics for evaluating XML Schemas quality. In this paper we will analyze existing XML metrics and their usage and try to hand out preliminary proposal for XML Schema quality framework.

Software Reliability Engineering, 2005. …, 2005

The eXtensible Markup Language (XML) is widely used to transmit data across the Internet. XML schemas are used to define the syntax of XML messages. XML-based applications can receive messages from arbitrary applications, as long as they follow the protocol defined by the schema. A receiving application must either validate XML messages, process the data in the XML message without validation, or modify the XML message to ensure that it conforms to the XML schema. A problem for developers is how well the application performs the validation, data processing, and, when necessary, transformation. This paper describes and gives examples of a method to generate tests for XML-based communication by modifying and then instantiating XML schemas. The modified schemas are based on precisely defined schema primitive perturbation operators.

2005

In this paper we investigate the problem of XML Schema evolution. We first discuss the different kinds of changes that may be needed on an XML Schema. Then, we investigate how to minimize document revalidation, that is, detecting the document parts potentially invalidated by the schema changes that should be revalidated.

Proceedings of the 14th ACM SIGPLAN international conference on Functional programming - ICFP '09, 2009

During the life cycle of an XML application, both schemas and queries may change from one version to another. Schema evolutions may affect query results and potentially the validity of produced data. Nowadays, a challenge is to assess and accommodate the impact of these changes in evolving XML applications. Such questions arise naturally in XML static analyzers. These analyzers often rely on decision procedures such as inclusion between XML schemas, query containment and satisfiability. However, existing decision procedures cannot be used directly in this context. The reason is that they are unable to distinguish information related to the evolution from information corresponding to bugs. This paper proposes a predicate language within a logical framework that can be used to make this distinction. We present a system for monitoring the effect of schema evolutions on the set of admissible documents and on the results of queries. The system is very powerful in analyzing various scenarios where the result of a query may not be anymore what was expected. Specifically, the system is based on a set of predicates which allow a fine-grained analysis for a wide range of forward and backward compatibility issues. Moreover, the system can produce counterexamples and witness documents which are useful for debugging purposes. The current implementation has been tested with realistic use cases, where it allows identifying queries that must be reformulated in order to produce the expected results across successive schema versions.

2011

issre, 2001

Web software systems are built using heterogeneous software components. They interact by passing messages that exchange data and activity state information. Such heterogeneous message transfers can be structured using the eXtensible Markup Language (XML), which allows a flexible common data exchange. Parsers have been developed to check syntax of component interactions, but there are as yet no techniques for checking the semantic correctness of the interactions. This paper presents a technique for using mutation analysis to test the semantic correctness of XMLbased component interactions. In this paper, the web software interactions are specified using an Interaction Specification Model (ISM) that consists of document type definitions, messaging specifications, and a set of constraints. Test cases are XML messages that are passed between the web software components. Classes of interaction-specific mutation operators are introduced and applied to the ISM to generate mutant interactions and test cases.

2004

Consistent design of XML schema within an organization or single integration project can reduce the number and the severity of interoperability problems. In addition, this consistency makes the XML schema easier to extend, understand, implement, and maintain; and, it paves the way for automated testing and mapping. Applying best practices is one way to achieve this design consistency. The literatures in the reference section advocate a number of recommended best practices for designing business message standards. In reviewing the recommendations from different references, we discovered that no single agreed upon set of best practices exists. Using a coherent subset of these recommendations, NIST researchers developed a collection of test requirements. These test requirements are maintained separately and organized according to the original reference documents on which they were based. This paper describes some of these requirements and provides rationale, explanations, examples, and comments for each. These requirements form part of a framework, which can be used to assess the overall quality of an XML schema. Other parts of the framework include computer executable test cases and test profiles. Briefly, test cases are used to verify the conformance to those requirements and test profiles are groups of test requirements. Test profiles are entry points for executing a set of test cases. More information about test cases and test profiles, which are not described in this paper, can be found in [12]. The audience of this document includes XML architect and systems integration managers who are looking for XML schema guidelines to XML message development. The reader is assumed to have working knowledge of XML and XML Schema. 2. Summary of Test Requirements This section summarizes design requirements included in this document. The summaries are given for each requirement table in the same order as those included in sections 7-14. 2.1. Requirement from OAGI Design Document The Open Application Group Inc. (OAGI) design document [1] contains eleven (11) design requirements. These requirements are elementary practices for an XML architecture. Most are fully testable and most are generic across organizations. Consequently, any organization can test against these requirements, although slight variations may be required. 2.2. Requirements from NIST B2B Testbed Recommendation Design requirements in Section 8 are obtained over the course of the National Institute of Standards and Technology (NIST) Business-to-Business (B2B) Testbed project [22]. Test cases written for a number of requirements included in this recommendation require heuristics. Consequently, the evaluation is approximation. Moreover, they require reference data and organizational specific data. We recommend that XML architect should consider adopting requirements #50, #200, #650 as baseline XML schema design practices.

Sigmod Record, 2009

XML has conquered its place as the most used standard for representing Web data. An XML schema may be employed for similar purposes of those from database schemas. There are different languages to write an XML schema, such as DTD and XSD. In this paper, we provide a general view, an X-Ray, on Web-available XSD files by identifying which XSD constructs are more and less frequently used. Furthermore, we provide an evolution perspective, showing results from XSD files collected in 2005 and 2008. Hence, we can also draw some conclusions on what trends seem to exist in XSD usage. The results of such study provide relevant information for developers of XML applications, tools and algorithms in which the schema has a distinguished role.

As XML 5] is emerging as the data format of the internet era, there is an substantial increase of the amount of data in XML format. To better describe such XML data structures and constraints, several XML schema languages have been proposed. In this paper, we present a comparative analysis of six noteworthy XML schema languages.

2002

XML (extensible Markup Language) technologies seem to offer solutions for a wide range of automated testing issues. In fact, these technologies are very promising to address scalability and interoperability among distributed software applications and to facilitate reuse ensuring data coherency, completeness and reliability. In this paper we discuss the use of XML for representing the whole set of information regarding configuration and classification data involved with a software environment for test automation. Thus we introduce a case study where the effectiveness of this approach was used to face the automated testing of telecommunication device.

2005

XML Schema is becoming an indispensable component in developing web applications. With its widespread adoption and its web accessibility, XML Schema reuse is becoming imperative. To support XML Schema reuse, the first step is to develop mechanism to search for relevant XML Schemas over the web. This paper describes a XML Schema matching system that compares two XML Schemas. Our matching system can find accurate matches and scales to large XML Schemas with hundreds of elements. In this system, XML Schemas are modelled as labeled, unordered and rooted trees, and a new tree matching algorithm is developed. Compared with the tree edit-distance algorithm and other schema matching systems, it is faster and more suitable for XML Schema matching.