A Quantitative Analysis of Open Source Software Code Quality: Insights from Metric Distributions

Code quality is a construct in open-source software (OSS) with three dimensions: maintainability, reliability, and functionality. We identify 20 distinct metrics and categorize them into two types: 1) monotonic metrics that consistently influence code quality; and 2) non-monotonic metrics that lack a consistent relationship for evaluation. We propose a distribution-based method to evaluate both types, which demonstrates great explainability of OSS adoption. Our empirical analysis includes more than 36,460 OSS repositories and their raw metrics from SonarQube and CK. Our work contributes to the multi-dimensional construct of code quality and its metric measurements.