Add automatic linter

[ineiti]

To make the code look better, apply an automatic linter. The chosen linter is the Google-java-formatter from https://github.com/google/google-java-format, which can also be installed in your IDE.

It is included as a https://pre-commit.com/ rule, so that it can be automatically applied whenever the code is committed. Additionally, a github-action makes sure that all code is correctly linted.

If you want to run this locally, you have to install https://pre-commit.com/. Then you can do:

pre-commit run

before every commit, or on Mac and Linux:

pre-commit install

To have it automatically be run when committing.

This PR is huge, because it has the linter applied to the code.

Closes #223

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities (and 2 Security Hotspots to review)
13 Code Smells

73.5% Coverage
2.6% Duplication

[ineiti]

@martinalig asks how to go forward with this, with regard to all the other PRs. My proposition is:

• merge this PR
• all other PRs need to do the following:

  git fetch
  # Either merge or rebase, according to your normal workflow
  git merge/rebase origin/pre-linting
  git checkout origin/develop .pre-commit-config.yaml .github/workflows/pre-commit.yaml
  # The following command fails because it had to format all java files. If you run it again, it will succeed
  pre-commit run --all-files
  git commit -am "Branch with linted files"
  git checkout origin/linter_done
  git checkout -b old_branch_linted
  git checkout old_branch .
  git commit -am "Branch with linted files depending on develop"
  git rebase origin/develop

Then the changes should be minimal.

Problem with this solution: you lose all commit-history!

[martinalig]

Perfect, works for me!