VALTEST: Automated Validation of Language Model Generated Test Cases

Large Language Models (LLMs) have demonstrated significant potential in automating software testing, specifically in generating unit test cases. However, the validation of LLM-generated test cases remains a challenge, particularly when the ground truth is unavailable. This paper introduces VALTEST, a novel framework designed to automatically validate test cases generated by LLMs by leveraging token probabilities. We evaluate VALTEST using nine test suites generated from three datasets (HumanEval, MBPP, and LeetCode) across three LLMs (GPT-4o, GPT-3.5-turbo, and LLama3.1 8b). By extracting statistical features from token probabilities, we train a machine learning model to predict test case validity. VALTEST increases the validity rate of test cases by 6.2% to 24%, depending on the dataset and LLM. Our results suggest that token probabilities are reliable indicators for distinguishing between valid and invalid test cases, which provides a robust solution for improving the correctness of LLM-generated test cases in software testing. In addition, we found that replacing the identified invalid test cases by VALTEST, using a Chain-of-Thought prompting results in a more effective test suite while keeping the high validity rates.

EPiC: Cost-effective Search-based Prompt Engineering of LLMs for Code Generation

Large Language Models (LLMs) have seen increasing use in various software development tasks, especially in code generation. The most advanced recent methods attempt to incorporate feedback from code execution into prompts to help guide LLMs in generating correct code, in an iterative process. While effective, these methods could be costly and time-consuming due to numerous interactions with the LLM and the extensive token usage. To address this issue, we propose an alternative approach named Evolutionary Prompt Engineering for Code (EPiC), which leverages a lightweight evolutionary algorithm to evolve the original prompts toward better ones that produce high-quality code, with minimal interactions with LLM. Our evaluation against state-of-the-art (SOTA) LLM-based code generation models shows that EPiC outperforms all the baselines in terms of cost-effectiveness.

A Novel Experts Advice Aggregation Framework Using Deep Reinforcement Learning for Portfolio Management

Solving portfolio management problems using deep reinforcement learning has been getting much attention in finance for a few years. We have proposed a new method using experts signals and historical price data to feed into our reinforcement learning framework. Although experts signals have been used in previous works in the field of finance, as far as we know, it is the first time this method, in tandem with deep RL, is used to solve the financial portfolio management problem. Our proposed framework consists of a convolutional network for aggregating signals, another convolutional network for historical price data, and a vanilla network. We used the Proximal Policy Optimization algorithm as the agent to process the reward and take action in the environment. The results suggested that, on average, our framework could gain 90 percent of the profit earned by the best expert.