#7: Adds developer guide (#8)

* Added developer guide
* Update doc/development/developer_guide.md

Co-authored-by: Anastasiia Sergienko <46891819+AnastasiiaSergienko@users.noreply.github.com>

README.md

@@ -16,6 +16,10 @@ programming language.
 
 - [Changelog](doc/changes/changelog.md)
 
+## Information for Contributors
+
+* [Developer Guide](doc/development/developer_guide.md)
+
 ## Dependencies
 
 ### Runtime Dependencies

doc/development/developer_guide.md

@@ -0,0 +1,187 @@
+# Developer Guide
+
+This guide provides development workflows that are used to develop and maintain
+the import-export-udf-common-scala and the projects based on it. It is intended for those who wish to address
+the issues, merge a pull request, perform release or deep dive into the codebase
+of the project.
+
+## Contributing
+
+Contributions to the import-export-udf-common-scala projects are very welcome!
+
+Please feel free to report a bug, suggest an idea for a feature, or ask a
+question about the code.
+
+Please keep in mind that contributions are not only pull requests. They can be
+any helpful comment on issues, improving documentation, enhancing the build process
+and many other tasks.
+
+### Getting in Touch
+
+Please feel free to report a bug, suggest an idea for a feature, or ask a
+question about the code.
+
+You can create an issue using [Github issues][gh-issues] or follow a standard
+[fork and pull][fork-and-pull] process to contribute a code via [Github pull
+requests][gh-pulls].
+
+If you do not know where to start, please have a look at [open
+issues][open-issues]. You can choose the ones that interest you the most. If you
+are new to the project, check out the issues labeled as
+[good-first-issue][first-issue].
+
+### Submitting a Pull Request
+
+Once you have found an interesting feature or issue to contribute, you can
+follow the steps below to submit your patches.
+
+- Create a new feature branch, `git checkout -b "cool-new-feature"`
+- Code
+- Write tests for changes
+- Update documentation if needed
+- **Make sure everything is working**, run `./scripts/ci.sh`
+- If everything is okay, commit and push to your fork
+- [Submit a pull request][submit-pr]
+- Let us work together to get your changes reviewed
+- Merge into master or development branches
+
+If your commit fixes any particular issue, please specify it in your commit
+message as `Fixes issue [issue number]`. For example, `Fixes issue #29`.
+
+Some best practices when creating a pull request:
+
+- Rebase or update
+- Squash your commits
+- Reword your commits
+- Write clear commit messages
+
+## Development Environment
+
+You need to have Java version 11 or above installed on your development
+machine.
+
+Additionally, we assume you have some experience doing Scala development. If you
+have any questions in general or about the development process, please feel free
+to get in touch.
+
+## Building the Project
+
+First clone a local copy of the repository:
+
+```bash
+git clone https://github.com/exasol/import-export-udf-common-scala.git
+```
+
+Then run `./sbtx`, and run any of these commands:
+
+- `clean`       : cleans previously compiled outputs; to start clean again.
+- `compile`     : compiles the source files.
+- `test:compile`: compiles the unit test files.
+- `it:compile`  : compiles the integration test files.
+- `test`        : run all the unit tests.
+- `it:test`     : run all the integration tests.
+- `doc`         : generate the api documentation.
+
+You can also run several commands combined together:
+
+```
+;clean;test;it:test
+```
+
+Additionally, you can run `testOnly filename` or `it:testOnly filename` commands
+to only run single file tests.
+
+### Running E2E Build Script
+
+Inside the `scripts/` folder, you will find the `ci.sh` bash file, that runs
+end-to-end build process. This file is intended to be run in continuous
+integration (CI) environment. For the continuous integration we use the [Travis
+CI](https://travis-ci.com/).
+
+Please run this file to make sure that everything is working before committing
+code or submitting a pull request.
+
+```bash
+./scripts/ci.sh
+```
+
+Additionally, ensure that the `ci.sh` scripts work with different versions of
+the Scala programming language. You can check that with the following command:
+
+```bash
+TRAVIS_SCALA_VERSION=2.11.12 ./scripts/ci.sh
+```
+
+## Checking the Test Coverage
+
+The `ci.sh` script also creates the code coverage reports. They are located in
+the target path, `target/scala-<SCALA.VERSION>/scoverage-report/`.
+
+You can open the `index.html` file, it should show the code coverage reports per
+file.
+
+![alt text](../images/code_coverage_example.png "Code Coverage Example")
+
+You can also generate the coverage reports using the `sbt` command line, by
+running:
+
+```bash
+;clean;coverage;test;it:test;coverageReport
+```
+
+## Checking the Dependency Updates
+
+It is important to keep the dependencies up to date.
+
+You can check out if any of dependencies or plugins have new versions, by
+running the following commands.
+
+Check if any plugins have new versions:
+
+```bash
+pluginUpdates
+```
+
+Check if any dependencies have new versions:
+
+```bash
+dependencyUpdates
+```
+
+### Dependency Tree and Artifact Eviction
+
+You can check the dependency tree by running the command below:
+
+```bash
+dependencyTree
+```
+
+Additionally, it is also good practice to check the evicted artifacts, and maybe
+to exclude them explicitly when declaring the library dependencies. In order to
+check the evicted artifacts, run:
+
+```bash
+evicted
+```
+
+## Editor Setups
+
+We try to keep the codebase code editor agnostic. But we tested that it works
+with IntelliJ.
+
+Any setups required for editors are out of scope. However, this can change when
+we get contributors who use those code editors :)
+
+## Conclusion
+
+This guide is expected to change and evolve with the changes to the project.
+Any pull requests to keep this document updated are very much appreciated!
+
+[gh-issues]: https://github.com/exasol/import-export-udf-common-scala/issues
+[gh-pulls]: https://github.com/exasol/import-export-udf-common-scala/pulls
+[fork-and-pull]: https://help.github.com/articles/using-pull-requests/
+[gh-releases]: https://github.com/exasol/import-export-udf-common-scala/releases
+[submit-pr]: https://github.com/exasol/import-export-udf-common-scala/compare
+[open-issues]: https://github.com/exasol/import-export-udf-common-scala/issues
+[first-issue]: https://github.com/exasol/import-export-udf-common-scala/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22
+[import-export-udf]: https://docs.exasol.com/loading_data/user_defined_import_export_using_udfs.htm