Overview

The modification history of a program is represented by its version control log and can be a huge source of interesting insights, in particular if combined with static source code analysis. This program analyses a git history and provides multiple modules (currently: one) to compute fascinating insights.

Installation

This is a standard gradle project, i.e. you build it via

gradle build

Note that in addition to the usual output in the build/ directory a standalone executable file git-analyzer will be created in the code's root directory as well (and removed on gradle clean).

Run

Start the analyzer without arguments to see the available options:

$ # gradle build
$ ./git-analyzer 
Value for option --directory should be always provided in command line.
Usage: git-analyzer options_list
Options: 
    --directory, -d -> Source code directory (always required) { String }
    --period, -p [128y] -> Period, e.g. 1y, 2w, 2w3d, ... { String }
    --analysis, -a [PackageExperts] -> Analysis to execute { Value should be one of [packageexperts] }
    --help, -h -> Usage info 

By default, you only need to provide a directory pointing to a git repository. For example, to gather statistics for JUnit5 using the current default analyzer, write

$ git clone https://github.com/junit-team/junit5.git /tmp/junit5
$ ./git-analyzer --directory /tmp/junit5

{
<a lot of json output>
 "platform.tooling.support.tests" : {
    "Sam Brannen <sbrannen@vmware.com>" : 1,
    "Juliette de Rancourt <derancourt.juliette@gmail.com>" : 2,
    "Christian Stein <sormuras@gmail.com>" : 76,
    "JUnit Team <team@junit.org>" : 85,
    "Marc Philipp <mail@marcphilipp.de>" : 113
  },
  "standalone" : {
    "Christian Stein <sormuras@gmail.com>" : 1,
    "Sam Brannen <sbrannen@pivotal.io>" : 3,
    "JUnit Team <team@junit.org>" : 9
  }
}

The package platform.tooling.support.tests has been edited by five different accounts and Marc Philipp had the most commits (113) and could be considered the technial expert; note that this analysis might be skewed by team accounts such as the "JUnit Team", so be aware of that.

By specifying --period you can restrict analysis to a specific period, e.g. last 100 days via --period 100d, last 3 months via --period 3m etc.

Example: Interactive filtering with jq and fzf

This repository also provides an exemplary script which shows how to use the JSON output in combination which modern UNIX tools like jq and fzf. See scripts/query.sh:

Modules

packageexperts

Splits up the code base by packages and determines experts via their respective number of commits. Currently, does not take renamed files into account.

Open topics

• Write tests
• Build via GitHub actions
• Add more modules, e.g. files often changed together, most changed files per package, ...

License

The source code is licensed under the Apache license