Add developer guide to the documentation

doc/developer_guide/index.md

@@ -0,0 +1,185 @@
+# Setting up a development environment
+
+The GeoViews library is a project that provides a wide range of data interfaces and an extensible set of plotting backends, which means the development and testing process involves a broad set of libraries.
+
+This guide describes how to install and configure development environments.
+
+If you have any problems with the steps here, please reach out in the `dev` channel on [Discord](https://discord.gg/rb6gPXbdAr) or on [Discourse](https://discourse.holoviz.org/).
+
+## Preliminaries
+
+### Basic understanding of how to contribute to Open Source
+
+If this is your first open-source contribution, please study one
+or more of the below resources.
+
+- [How to Get Started with Contributing to Open Source | Video](https://youtu.be/RGd5cOXpCQw)
+- [Contributing to Open-Source Projects as a New Python Developer | Video](https://youtu.be/jTTf4oLkvaM)
+- [How to Contribute to an Open Source Python Project | Blog post](https://www.educative.io/blog/contribue-open-source-python-project)
+
+### Git
+
+The GeoViews source code is stored in a [Git](https://git-scm.com) source control repository. The first step to working on GeoViews is to install Git onto your system. There are different ways to do this, depending on whether you use Windows, Mac, or Linux.
+
+To install Git on any platform, refer to the [Installing Git](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git) section of the [Pro Git Book](https://git-scm.com/book/en/v2).
+
+To contribute to GeoViews, you will also need [Github account](https://github.com/join) and knowledge of the [_fork and pull request workflow_](https://docs.github.com/en/get-started/quickstart/contributing-to-projects).
+
+### Pixi
+
+Developing all aspects of GeoViews requires a wide range of packages in different environments. To make this more manageable, Pixi manages the developer experience. To install Pixi, follow [this guide](https://pixi.sh/latest/#installation).
+
+#### Glossary
+
+- Tasks: A task is what can be run with `pixi run <task-name>`. Tasks can be anything from installing packages to running tests.
+- Environments: An environment is a set of packages installed in a virtual environment. Each environment has a name; you can run tasks in a specific environment with the `-e` flag. For example, `pixi run -e test-core test-unit` will run the `test-unit` task in the `test-core` environment.
+- Lock-file: A lock-file is a file that contains all the information about the environments.
+
+For more information, see the [Pixi documentation](https://pixi.sh/latest/).
+
+:::{admonition} Note
+:class: info
+
+The first time you run `pixi`, it will create a `.pixi` directory in the source directory.
+This directory will contain all the files needed for the virtual environments.
+The `.pixi` directory can be large, so it is advised not to put the source directory into a cloud-synced directory.
+:::
+
+## Installing the Project
+
+### Cloning the Project
+
+The source code for the GeoViews project is hosted on [GitHub](https://github.com/holoviz/geoviews). The first thing you need to do is clone the repository.
+
+1. Go to [github.com/holoviz/geoviews](https://github.com/holoviz/geoviews)
+2. [Fork the repository](https://docs.github.com/en/get-started/quickstart/contributing-to-projects#forking-a-repository)
+3. Run in your terminal: `git clone https://github.com/<Your Username Here>/geoviews`
+
+The instructions for cloning above created a `geoviews` directory at your file system location.
+This `geoviews` directory is the _source checkout_ for the remainder of this document, and your current working directory is this directory.
+
+## Start developing
+
+To start developing, run the following command
+
+```bash
+pixi install
+```
+
+The first time you run it, it will create a `pixi.lock` file with information for all available environments. This command will take a minute or so to run.
+When this is finished, it is possible to run the following command to download the data GeoViews tests and examples depend upon.
+
+```bash
+pixi run -e download-data download-data
+```
+
+All available tasks can be found by running `pixi task list`, the following sections will give a brief introduction to the most common tasks.
+
+### Syncing Git tags with upstream repository
+
+If you are working from a forked repository of GeoViews, you will need to sync the tags with the upstream repo.
+This is needed because the GeoViews version number depends on [`git tags`](https://git-scm.com/book/en/v2/Git-Basics-Tagging).
+Syncing the git tags can be done with:
+
+```bash
+pixi run sync-git-tags
+```
+
+### Editable install
+
+It can be advantageous to install the GeoViews in [editable mode](https://pip.pypa.io/en/stable/topics/local-project-installs/#editable-installs):
+
+```bash
+pixi run install
+```
+
+:::{admonition} Note
+:class: info
+
+Currently, this needs to be run for each environment. So, if you want to install in the `test-ui` environment, you can add `--environment` / `-e` to the command:
+
+```bash
+pixi run -e test-ui install
+```
+
+:::
+
+## Linting
+
+GeoViews uses [pre-commit](https://pre-commit.com/) to apply linting to GeoViews code. Linting can be run for all the files with:
+
+```bash
+pixi run lint
+```
+
+Linting can also be set up to run automatically with each commit; this is the recommended way because if linting is not passing, the [Continuous Integration](https://en.wikipedia.org/wiki/Continuous_integration) (CI) will also fail.
+
+```bash
+pixi run lint-install
+```
+
+## Testing
+
+To help keep GeoViews maintainable, all Pull Requests (PR) with code changes should typically be accompanied by relevant tests. While exceptions may be made for specific circumstances, the default assumption should be that a Pull Request without tests will not be merged.
+
+There are three types of tasks and five environments related to tests.
+
+### Unit tests
+
+Unit tests are usually small tests executed with [pytest](https://docs.pytest.org). They can be found in `geoviews/tests/`.
+Unit tests can be run with the `test-unit` task:
+
+```bash
+pixi run test-unit
+```
+
+The task is available in the following environments: `test-310`, `test-311`, `test-312`, and `test-core`. Where the first ones have the same environments except for different Python versions, and `test-core` only has a core set of dependencies.
+
+If you haven't set the environment flag in the command, a menu will help you select which one of the environments to use.
+
+### Example tests
+
+GeoViews's documentation consists mainly of Jupyter Notebooks. The example tests execute all the notebooks and fail if an error is raised. Example tests are possible thanks to [nbval](https://nbval.readthedocs.io/) and can be found in the `examples/` folder.
+Example tests can be run with the following command:
+
+```bash
+pixi run test-example
+```
+
+This task has the same environments as the unit tests except for `test-core`.
+
+## Documentation
+
+The documentation can be built with the command:
+
+```bash
+pixi run docs-build
+```
+
+As GeoViews uses notebooks for much of the documentation, this will take significant time to run (around an hour).
+
+A development version of GeoViews can be found [here](https://dev.geoviews.org/). You can ask a maintainer if they want to make a dev release for your PR, but there is no guarantee they will say yes.
+
+## Build
+
+GeoViews have three build tasks. One is for building packages for Pip, Conda, and NPM.
+
+```bash
+pixi run build-pip
+pixi run build-conda
+pixi run build-npm
+```
+
+## Continuous Integration
+
+Every push to the `main` branch or any PR branch on GitHub automatically triggers a test build with [GitHub Actions](https://github.com/features/actions).
+
+You can see the list of all current and previous builds at [this URL](https://github.com/holoviz/geoviews/actions)
+
+### Etiquette
+
+GitHub Actions provides free build workers for open-source projects. A few considerations will help you be considerate of others needing these limited resources:
+
+- Run the tests locally before opening or pushing to an opened PR.
+
+- Group commits to meaningful chunks of work before pushing to GitHub (i.e., don't push on every commit).

doc/index.rst

@@ -96,5 +96,6 @@ or have set up your system to be able to build them.
    User Guide <user_guide/index>
    Gallery <gallery/index>
    Topics <topics>
+   Developer Guide <developer_guide/index>
    Releases <releases>
    About <about>