TBD suitable techniques for querying git repos

### Context
NLnet funds opensource projects; these projects host their code on a variety of code hosting services including github, gitlab, and others. Some of these, including github, provide mechanisms to query codebases they host. The mechanisms are likely to vary in their APIs, methods, and the data they return. We will start iteratively by using github's APIs to bootstrap the analysis of information about testing which will then help shape our understanding of the information that we find pertinent. That will then help us determine how we might obtain this information from the various code hosting services.
### Objectives

- To find reliable, performance, and viable mechanisms to extract pertinent information from git codebases and/or their hosting providers related to the testing of those codebases.
- To encourage an iterative, learning-oriented approach that supports multiple approaches especially during the early stages of learning.

### Abstractions
Broadly the information can be obtained from various sources, including asking:

1. the developer(s)
2. the testing framework(s)
3. the hosting provider e.g. github.com
4. the operating system and file system
5. git

Each provides distinct facets of information, including about the accuracy, completeness, and perception of any tests that are related to the repo. We aim to obtain answers from at least one of these for every repository supported by NLnet foundation. Where practical, the one providing the most insight will be chosen, and at least one of the code-based sources will be queried in addition to whatever perspective developers can provide.

### Querying git
Much of the underlying information will be in an instance of the codebase that includes the git history. Therefore it'll be worth us investigating how we might interface with a git repo independently of where the repo is hosted, e.g. on a local cloned copy of the respective repo.
### Work in this area
Source code analysis in codebases is an active area of academic research e.g. as part of Mining Software Repositories (MSR) and there are very likely to be tools and techniques we can use and apply to help us with our work.

- [Logging Practices with Mobile Analytics: An Empirical Study on Firebase](https://doi.org/10.1109/MobileSoft52590.2021.00013) was work I was involved in. Please add additional research and tools as comments to this ticket.