Predicting Code Coverage without Execution
Authors: name: Michele Tufano; name: Shubham Chandel; name: Anisha Agarwal; name: Neel Sundaresan; name: Colin Clement
Published: 2023-07-25 10:07:02

Abstract: Code coverage is a widely used metric for quantifying the extent to which
program elements, such as statements or branches, are executed during testing.
Calculating code coverage is resource-intensive, requiring code building and
execution with additional overhead for the instrumentation. Furthermore,
computing coverage of any snippet of code requires the whole program context.
Using Machine Learning to amortize this expensive process could lower the cost
of code coverage by requiring only the source code context, and the task of
code coverage prediction can be a novel benchmark for judging the ability of
models to understand code. We propose a novel benchmark task called Code
Coverage Prediction for Large Language Models (LLMs). We formalize this task to
evaluate the capability of LLMs in understanding code execution by determining
which lines of a method are executed by a given test case and inputs. We curate
and release a dataset we call COVERAGEEVAL by executing tests and code from the
HumanEval dataset and collecting code coverage information. We report the
performance of four state-of-the-art LLMs used for code-related tasks,
including OpenAI's GPT-4 and GPT-3.5-Turbo, Google's BARD, and Anthropic's
Claude, on the Code Coverage Prediction task. Finally, we argue that code
coverage as a metric and pre-training data source are valuable for overall LLM
performance on software engineering tasks.