Valerio Terragni

Verified

Valerio verified their affiliation via an institutional email.

Learn more

Verified

Valerio verified their affiliation via an institutional email.

Learn more

• PhD
• Senior Lecturer at University of Auckland

A paradigm shift is underway in Software Engineering, with AI systems such as LLMs playing an increasingly important role in boosting software development productivity. This trend is anticipated to persist. In the next years, we expect a growing symbiotic partnership between human software developers and AI. The Software Engineering research commun...

Libraries assist in accelerating the development of software applications by providing reusable functionalities. Libraries and applications that declare these libraries as dependencies become their clients. However, as libraries evolve, maintaining the dependencies in client projects can be challenging if the new version contains breaking changes....

Machine learning (ML) for text classification has been widely used in various domains, such as toxicity detection, chatbot consulting, and review analysis. These applications can significantly impact ethics, economics, and human behavior, raising serious concerns about trusting ML decisions. Several studies indicate that traditional metrics, such a...

While a recent study reveals that many developer-written test cases can encode a reusable Metamorphic Relation (MR), over 70% of them directly hard-code the source input and follow-up input in the encoded relation. Such encoded MRs, which do not contain an explicit input transformation to transform the source inputs to corresponding follow-up input...

Libraries play a significant role in software development as they provide reusable functionality, which helps expedite the development process. As libraries evolve, they release new versions with optimisations like new functionality, bug fixes, and patches for known security vulnerabilities. To obtain these optimisations, the client applications th...

Metamorphic testing is a popular approach that aims to alleviate the oracle problem in software testing. At the core of this approach are Metamorphic Relations (MRs), specifying properties that hold among multiple test inputs and corresponding outputs. Deriving MRs is mostly a manual activity, since their automated generation is a challenging and l...

A paradigm shift is underway in Software Engineering, with AI systems such as LLMs gaining increasing importance for improving software development productivity. This trend is anticipated to persist. In the next five years, we will likely see an increasing symbiotic partnership between human developers and AI. The Software Engineering research comm...

Machine Learning (ML) has become an integral part of our society, commonly used in critical domains such as finance, healthcare, and transportation. Therefore, it is crucial to evaluate not only whether ML models make correct predictions but also whether they do so for the correct reasons, ensuring our trust that will perform well on unseen data. T...

Reusing test cases across apps that share similar functionalities reduces both the effort required to produce useful test cases and the time to offer reliable apps to the market. The main approaches to reuse test cases across apps combine different semantic matching and test generation algorithms to migrate test cases across Android apps. In this p...

Metamorphic Testing (MT) alleviates the oracle problem by defining oracles based on metamorphic relations (MRs), that govern multiple related inputs and their outputs. However, designing MRs is challenging, as it requires domain-specific knowledge. This hinders the widespread adoption of MT. We observe that developer-written test cases can embed do...

Computing education plays a significant role in the calibre of computing professionals; hence, improving its quality is a valuable endeavour. A promising means for such an endeavour is the harnessing of student data from version control systems. This has previously been used to predict academic performance, but a gap lies in its usage for learning...

A professional software engineer needs excellent communication skills, a thorough understanding of software licensing and ethics, and the ability to follow standards in code style and version control. Albeit professionalism is a crucial aspect of Software Engineering, students are usually exposed to it later in their academic degree. We advocate fo...

Mocking is an essential unit testing technique for isolating the class under test (CUT) from its dependencies. Developers often leverage mocking frameworks to develop stub code that specifies the behaviors of mock objects. However, developing and maintaining stub code is labor-intensive and error-prone. In this paper, we present StubCoder to automa...

Mocking is an essential unit testing technique for isolating the class under test (CUT) from its dependencies. Developers often leverage mocking frameworks to develop stub code that specifies the behaviors of mock objects. However, developing and maintaining stub code is labor-intensive and error-prone. In this paper, we present StubCoder to automa...

Modern software applications rely heavily on the usage of libraries, which provide reusable functionality, to accelerate the develop ment process. As libraries evolve and release new versions, the software systems that depend on those libraries (the clients) should update their dependencies to use these new versions as the new release could, for ex...

Metamorphic testing alleviates the test oracle problem by defining oracles based on relations (i.e., metamorphic relations) that govern multiple related inputs and their expected outputs. However, designing MRs requires domain-specific knowledge, which may not be generally available. This hinders the widespread adoption of MT. Fortunately, we obser...

Testing is an important activity in software engineering, especially with the growing adoption of software systems in safety-critical domains. Testing research, however, is mostly focused on deter- mining which test inputs to use (e.g., proposing and evaluating test coverage criteria or automatic test generation tools). Re- gardless of the used cov...

The growing application of DL makes detecting and fixing defective DL programs of paramount importance. Recent studies on DL defects report that TensorFlow API misuses represent a common class of DL defects. However to effectively detect, fix, and verify them remains an understudied problem. This paper presents the TensorFlow API misuses Detector A...

Semantic GP is a promising branch of GP that introduces semantic awareness during genetic evolution to improve various aspects of GP. This paper presents a new Semantic GP approach based on Dynamic Target (SGP-DT) that divides the search problem into multiple GP runs. The evolution in each run is guided by a new (dynamic) target based on the residu...

Developer forums like StackOverflow have become essential resources to modern software development practices. However, many code snippets lack a well-defined method declaration, and thus they are often incomplete for immediate reuse. Developers must adapt the retrieved code snippets by parameterizing the variables involved and identifying the retur...

Developer forums like StackOverflow have become essential resources to modern software development practices. However, many code snippets lack a well-defined method declaration, and thus they are often incomplete for immediate reuse. Developers must adapt the retrieved code snippets by parameterizing the variables involved and identifying the retur...

One of the major challenges in the verification of complex industrial Cyber-Physical Systems is the difficulty of determining whether a particular system output or behaviour is correct or not, the so- called test oracle problem. Metamorphic testing alleviates the oracle problem by reasoning on the relations that are expected to hold among multiple...

GUI testing is an important but expensive activity. Recently, re- search on test reuse approaches for Android applications produced interesting results. Test reuse approaches automatically migrate human-designed GUI tests from a source app to a target app that shares similar functionalities. They achieve this by exploiting semantic similarity among...

Assertion oracles are executable boolean expressions placed inside a software program that verify the correctness of test executions. A perfect assertion oracle passes (returns true) for all correct executions and fails (returns false) for all incorrect executions. Because designing perfect assertion oracles is difficult, assertions often fail to d...

In the multi-class classification problem GP plays an important role when combined with other non-GP classifiers. However, when GP performs the actual classification (without relying on other classifiers) its classification accuracy is low. This is especially true when the number of classes is high. In this paper, we present DTC, a GP classifier th...

Concurrency testing is an important activity to expose concurrency faults in thread‐safe classes. A concurrent test for a thread‐safe class is a set of method call sequences that exercise the public interface of the class from multiple threads. Automatically generating fault‐revealing concurrent tests within an affordable time budget is difficult d...

This demo presents the implementation and usage details of GASSERT, the first tool to automatically improve assertion oracles. Assertion oracles are executable boolean expressions placed inside the program that should pass (return true) for all correct executions and fail (return false) for all incorrect executions. Because designing perfect assert...

Automatic generators of GUI tests often fail to generate semantically relevant test cases, and thus miss important test scenarios. To address this issue, test adaptation techniques can be used to automatically generate semantically meaningful GUI tests from test cases of applications with similar functionalities. In this paper, we present ADAPTDROI...

Automatic generators of GUI tests often fail to generate semantically relevant test cases, and thus miss important test scenarios. To address this issue, test adaptation techniques can be used to automatically generate semantically meaningful GUI tests from test cases of applications with similar functionalities. In this paper, we present ADAPTDROI...

This demo presents the implementation and usage details of GASSERT, the first tool to automatically improve assertion oracles. Assertion oracles are executable boolean expressions placed inside the program that should pass (return true) for all correct executions and fail (return false) for all incorrect executions. Because designing perfect assert...

Assertion oracles are executable boolean expressions placed inside the program that should pass (return true) for all correct executions and fail (return false) for all incorrect executions. Because designing perfect assertion oracles is difficult, assertions often fail to distinguish between correct and incorrect executions. In other words, they a...

Learning features from raw data is an important topic in machine learning. This paper presents Genetic Program Feature Learner (GPFL), a novel generative GP feature learner for 2D images. GPFL executes multiple GP runs, each run generates a model that focuses on a particular high-level feature of the training images. Then, it combines the models ge...

Comprehending the degree to which software components support testing is important to accurately schedule testing activities, train developers, and plan effective refactoring actions. Software testability estimates such property by relating code characteristics to the test effort. The main studies of testability reported in the literature investiga...

Semantic Genetic Programming (SGP) approaches demonstrated remarkable results in different domains. SGP-DT is one of the latest of such approaches. Notably, SGP-DT proposes a dynamic-target approach that combines multiple GP runs without relying on any form of crossover. On eight well-known datasets SGP-DT achieves small RMSE, on average 25% smalle...

Learning features from raw data is an important topic in machine learning. This paper presents a novel GP approach to learn high- level features from 2D images. It is a generative approach that resembles the concept of an autoencoder. Our approach executes multiple GP runs, each run generates a (partial) model that focuses on a particular high-leve...

Intermittent test failures (test flakiness) is common during con- tinuous integration as modern software systems have become in- herently non-deterministic. Understanding the root cause of test flakiness is crucial as intermittent test failures might be the result of real non-deterministic defects in the production code, rather than mere errors in...

Semantic GP is a promising approach that introduces semantic awareness during genetic evolution. This paper presents a new Semantic GP approach based on Dynamic Target (SGP-DT) that divides the search problem into multiple GP runs. The evolution in each run is guided by a new (dynamic) target based on the residual errors. To obtain the final soluti...

Semantic GP is a promising approach that introduces semantic awareness during genetic evolution. This paper presents a new Semantic GP approach based on Dynamic Target (SGP-DT) that divides the search problem into multiple GP runs. The evolution in each run is guided by a new (dynamic) target based on the residual errors. To obtain the final soluti...

Thread-safe classes are common in concurrent object-oriented programs. Testing such classes is important to ensure the reliability of the concurrent programs that rely on them. Recently, researchers have proposed the automated generation of concurrent (multi-threaded) tests to expose concurrency faults in thread-safe classes (thread-safety violatio...

Developing correct and efficient concurrent programs is difficult and error-prone, due to the complexity of thread synchronization. Often, developers alleviate such problem by relying on thread-safe classes, which encapsulate most synchronization-related challenges. Thus, testing such classes is crucial to ensure the reliability of the concurrency...

Reproducing field failures is the first essential step for understanding, localizing and removing faults. Reproducing concurrency field failures is hard due to the need of synthesizing a test code jointly with a thread interleaving that induce the failure in the presence of limited information from the field. Current techniques for reproducing conc...

Wake locks are widely used in Android apps to protect critical computations from being disrupted by device sleeping. Inappropriate use of wake locks often seriously impacts user experience. However, little is known on how wake locks are used in real-world Android apps and the impact of their misuses. To bridge the gap, we conducted a large-scale em...

Popular Q&A sites like StackOverflow have collected numerous code snippets. However, many of them do not have complete type information, making them uncompilable and inapplicable to various software engineering tasks. This paper analyzes this problem, and proposes a technique CSNIPPEX to automatically convert code snippets into compilable Java sour...

Previous techniques on concurrency testing have mainly focused on exploring the interleaving space of manually written test code to expose faulty interleavings of shared memory accesses. These techniques assume the availability of failure-inducing tests. In this paper, we present AutoConTest, a coverage-driven approach to generate effective concurr...

Concurrent programs proliferate as multi-core technologies advance. The regression testing of concurrent programs often requires running a failing test for weeks before catching a faulty interleaving, due to the myriad of possible interleavings of memory accesses arising from concurrent program executions. As a result, the conventional approach tha...

One of the most intriguing challenges in mobile apps development is its fragmentation with respect to mobile platforms (e.g., Android, Apple iOS, Windows Phone). Large companies like IBM and Adobe and a growing community of developers advocate hybrid mobile apps development as a possible solution to mobile platforms fragmentation. Hybrid mobile app...