Do not create an empty commit when generating report

[timtebeek]

Describe the bug
When I create a report to inform myself of the steps needed for a migration, an empty commit is created and added to the git history. As a user this is quite surprising; I would not expect a report generation that does not yet make any code changes to add anything to my git history. Perhaps that's intentional, but I'd thought to mildly challenge that here, as it makes the report generation more widely applicable if it does not create any git changes (yet).

To Reproduce
Steps to reproduce the behavior:

1. git clone [email protected]:spring-projects-experimental/spring-boot-migrator.git, currently at 21fce4d
2. cd spring-boot-migrator
3. ./mvnw install -DskipTests
4. java -jar applications/spring-shell/target/spring-boot-migrator.jar
5. scan ../any-other-project
6. apply --recipeName boot-2.7-3.0-upgrade-report2

Expected behavior
Only a generated report; no new commits added to the repository.

Instead I see a new commit:

SBM: applied recipe 'boot-2.7-3.0-upgrade-report2'

Desktop (please complete the following information):

• OS: Ubuntu 2022.04
• Version 21fce4d

[fabapp2]

@timtebeek Hm... I agree that an empty commit is useless and should be fixed. Not sure if I agree that no commit at all should be created. But I'm Interested in your reasoning.

[timtebeek]

In my view report generation is purely an informative step, to better judge any follow up code charging steps to take after that. The reports do not yet make code changes, and it's unlike that you'd want the report to be added to the repository. Hence why I would not yet expect a commit on the active branch, much less an empty commit at that.

Perhaps there'd be some value if the report commit is on a separate branch. But when users have the main branch checked out and generate a report, they could be surprised to find a new empty commit on the main branch, which typically can not be pushed directly for protected branches.

[fabapp2]

Hi @timtebeek
we reworked the Spring Boot Report from ground up. The shell is history for report generation (recipes and report generation should still work though) and will be (see branch webapp-demo) replaced with the HTML report that allows applying recipes from the report. the empty commit problem has been fixed in this branch. Using the Shell will currently still create a commit but when using the new report capability there are no commits for the generated report.
I like the new approach a lot and could see this replacing the shell completely over time.

[timtebeek]

Sounds promising! Glad to hear the issue is resolved on a branch. Feel free to already close this issue. I'll have no way to check until January. :)