Refactoring Analysis

This project analyzes merge commits in git repositries and determines whether refactoring changes are to blame for the conflicts. For the version of the code used in our SANER '19 paper, please check https://github.com/ualberta-smr/RefactoringsInMergeCommits/tree/saner19-cr.

System requirements

• Linux or macOS
• git
• Java 11
• MySQL 5.7

How to run

1. Create a database configuration file

Edit the database.properties file and add your MySQL username and password:

development.driver=com.mysql.jdbc.Driver
development.username=USERNAME
development.password=PASSWORD
development.url=jdbc:mysql://localhost/refactoring_analysis

If you wish, you can choose a different name for the database (refactoring_analysis in the template). Please make sure that another database with the same name doesn't exist, since it'll most likely have a different schema and the program will run into problems.

2. Create a list of repositories

The program requires a text file consisting of the git repositories you want to analyze. Each line in the text file should include the complete URL of a git repository. We have included the reposList.txt file that contains 2,954 repositories.

3. Build the project

Run the following command to compile the project and create an executable JAR file:

./mvnw clean activejdbc-instrumentation:instrument compile assembly:single clean

This command will create refactoring-analysis.jar file in the root directory.

4. Run the JAR file

You can run the JAR file with the following command:

java -jar refactoring-analysis.jar [OPTIONS]

Note that none of the options are required. Here is a list of available options:

-c,--clonepath <file>        directory to temporarily download repositories (default=projects)
-d,--dbproperties <file>     database properties file (default=database.properties)
-h,--help                    print this message
-p,--parallelism <threads>   number of threads for parallel computing (default=1)
-r,--reposfile <file>        list of repositories to be analyzed (default=reposList.txt)

Here is an example command with all the options:

 java -jar refactoring-analysis.jar -r list.txt -c downloadedRepos -d mydb.properties -p 8 

5. Generate stat summaries

After the program has finished running, you can use the Python scripts in the stats folder to look at the results.

• data_resolver.py: This script will print a summary of stats, including total number of merge scenarios, merge scenarios with involved refacotirngs, conflicting regions with involved refactorings, etc.
• plotter.py: This script can draw a number of different plots.

Replicate the results of SANER 2019 submission

For our SANER 2019 submission, we used the provided reposList.txt list of repositories. More information on how we created this list can be found here. However, if you start running the program on the same list you might get slightly different results. This is because our results are based on the state of the repositories on Oct 5, 2018, and new changes could have happened to the repositories since then.

You can find a dump of our results after we finished the analysis here.