# Contributing to eclipse hawkBit

:+1: First off, thanks for taking the time to contribute! We really appreciate this. :+1:

Please read this if you intend to contribute to the project.

## Conventions

### Code Style

* Java files:
  * we follow the standard eclipse IDE (built in) code formatter with the following changes:
    * Tab policy: spaces only: 4
  * We recommend using at least Eclipse [Mars](https://www.eclipse.org/mars/) IDE release. It seems that the Java code formatter line break handling has been changed between [Luna](https://www.eclipse.org/luna/) and Mars.
* XML files:
  * we follow the standard eclipse IDE XML formatter with the following changes:
    * Indent using spaces only: 3
* SCSS files:
  * we follow the standard [scss-lint](https://github.com/brigade/scss-lint/) rules with the following exception:
    * disabled rules: ImportantRule, PropertySortOrder
* Sonarqube:
  * Our rule set can be found [here](https://sonar.ops.bosch-iot-rollouts.com/projects) with navigating to the tab "Quality Profiles", selecting "hawkBit", and then selecting "Actions" - "Back up"

### Utility library usage

hawkBit has currently both [guava](https://github.com/google/guava) and [Apache commons lang](https://commons.apache.org/proper/commons-lang/) on the classpath in several of its modules. However, we see introducing too many utility libraries problematic as we force these as transitive dependencies on hawkBit users. We in fact are looking into reducing them in future not adding new ones.

So we kindly ask contributors:

* not introduce extra utility library dependencies
* keep them out of the core modules (e.g. hawkbit-core, hawkbit-rest-core, hawkbit-http-security) to avoid that all modules have them as transitive dependency
* use utility functions in general based in the following priority:
  * use utility functions from JDK if feasible
  * use Spring utility classes if feasible
  * use [guava](https://github.com/google/guava) if feasible
  * use [Apache commons lang](https://commons.apache.org/proper/commons-lang/) if feasible

Note that the guava project for instance often documents where they think that JDK is having a similar functionality (e.g. their thoughts on  [Throwables.propagate](https://github.com/google/guava/wiki/Why-we-deprecated-Throwables.propagate)).

Examples:

* Prefer `Arrays.asList(...)` from JDK over guava's `Lists.newArrayList(...)`
* Prefer `StringUtils` from Spring over guava's `Strings` Apache's `StringUtils`

### Test documentation

Please documented the test cases that you contribute by means of [Allure](https://docs.qameta.io/allure/) annotations and proper test method naming.

All test classes are documented with [Allure's](https://docs.qameta.io/allure/#_behaviours_mapping) **@Feature** and **@Story** annotations in the following format:
```
@Feature("TEST_TYPE - HAWKBIT_COMPONENT")
@Story("Test class description")
```

Test types are:

* Unit Tests - for single units tests with a mocked environment
* Component Tests - for complete components including lower layers, e.g. Spring MVC test on rest API including repository and database.
* Integration Tests - including clients, e.g. Selenium UI tests with various browsers.
* System Tests - on target environments, e.g. Cloud Foundry.

Examples for hawkBit components:

* Management API
* Direct Device Integration API
* Device Management Federation API
* Management UI
* Repository
* Security

```java
@Feature("Component Tests - Management API")
@Story("Distribution Set Type Resource")
```

In addition all test method's name describes in **camel case** what the test is all about and has in addition a long description in Allures **@Description** annotation.

## Legal considerations for your contribution

Before your contribution can be accepted by the project team contributors must
electronically sign the [Eclipse Contributor Agreement (ECA)](http://www.eclipse.org/legal/ECA.php).

Commits that are provided by non-committers must have a Signed-off-by field in
the footer indicating that the author is aware of the terms by which the
contribution has been provided to the project. The non-committer must
additionally have an Eclipse Foundation account and must have a signed Eclipse
Contributor Agreement (ECA) on file.

For more information, please see the Eclipse Committer Handbook:
https://www.eclipse.org/projects/handbook/#resources-commit

HowTo "Sign-off" your commits:

You do this by adding the `-s` flag when you make the commit(s), e.g.

    git commit -s -m "Shave the yak some more"

## Making your changes

* Fork the repository on GitHub
* Create a new branch for your changes
* Make your changes
* Make sure you include tests
* Make sure the tests pass after your changes
* Commit your changes into that branch
* Use descriptive and meaningful commit messages
* If you have a lot of commits squash them into a single commit
* Make sure you use the `-s` flag when committing as explained above.
* Push your changes to your branch in your forked repository

## Submitting the changes

Submit a pull request via the normal GitHub UI (desktop or web).

## After submitting

* Do not use your branch for any other development, otherwise further changes that you make will be visible in the PR.

## Further information

* [Eclipse Project Page](http://projects.eclipse.org/projects/iot.hawkbit)
