Contributing to libgweather =========================== Thank you for considering contributing to libgweather! These guidelines are meant for new contributors, regardless of their level of proficiency; following them allows the maintainers of libgweather to more effectively evaluate your contribution, and provide prompt feedback to you. Additionally, by following these guidelines you clearly communicate that you respect the time and effort that the people developing libgweather put into managing the project. This project is free software, and it would not exist without contributions from the free and open source software community. There are many things that we value: - bug reporting and fixing - documentation and examples - tests - testing and support for other platforms - new features Please, do **not** use the issue tracker for support questions. If you have questions on how to use libgweather effectively, you can use: - the [`gweather` tag on GNOME's Discourse](https://discourse.gnome.org/tags/gweather) The issue tracker is meant to be used for actionable issues only. ## How to report bugs ### Security issues You should not open a new issue for security related questions. Always use the [security report form](https://security.gnome.org) to ensure the relevant people are notified of your issue. ### Bug reports If you’re reporting a bug make sure to list: 0. which version of libgweather are you using? 0. which operating system are you using? 0. the necessary steps to reproduce the issue 0. the expected outcome 0. a description of the behavior 0. a small, self-contained example exhibiting the behavior If the issue includes a crash, you should also include: 0. the eventual warnings printed on the terminal 0. a backtrace, obtained with tools such as GDB or LLDB If the issue includes a memory leak, you should also include: 0. a log of definite leaks from a tool such as [valgrind’s memcheck](http://valgrind.org/docs/manual/mc-manual.html) For small issues, such as: - spelling/grammar fixes in the documentation, - typo correction, - comment clean ups, - changes to metadata files (CI, `.gitignore`), - build system changes, or - source tree clean ups and reorganizations; or for self-contained bug fixes where you have implemented and tested a solution already, you should directly open a merge request instead of filing a new issue. ### Features and enhancements Feature discussion can be open ended and require high bandwidth channels; if you are proposing a new feature on the issue tracker, make sure to make an actionable proposal, and list: 0. what you’re trying to achieve and the problem it solves 0. three (or more) existing pieces of software which would benefit from the new feature New APIs, in particular, should follow the ‘rule of three’, where there should be three (or more) pieces of software which are ready to use the new APIs. This allows us to check that the new APIs are usable in real-life code, and fit well with related APIs. If proposing a large feature or change, it’s better to discuss it on [Discourse](https://discourse.gnome.org) before putting time into writing an actionable issue — and certainly before putting time into writing a merge request. ## Your first contribution ### Prerequisites If you want to contribute to the libgweather project, you will need to have the development tools appropriate for your operating system, including: - Python 3.x - Meson - Ninja - Gettext (19.7 or newer) - a [C99 compatible compiler](https://wiki.gnome.org/Projects/GLib/CompilerRequirements) Up-to-date instructions about developing GNOME applications and libraries can be found on [the GNOME Developer Center](https://developer.gnome.org). The [libgweather project uses GitLab](https://gitlab.gnome.org/GNOME/libgweather/) for code hosting and for tracking issues. More information about using GitLab can be found [on the GNOME wiki](https://wiki.gnome.org/GitLab). ### Getting started You should start by forking the libgweather repository from the GitLab web UI, and cloning from your fork: ```sh $ git clone https://gitlab.gnome.org/yourusername/libgweather.git $ cd libgweather ``` To compile the Git version of libgweather on your system, you will need to configure your build using Meson: ```sh $ meson setup _builddir . $ meson compile -C _builddir ``` Typically, you should work on your own branch: ```sh $ git switch -C your-branch ``` The coding style of libgweather is maintained through [clang-format](https://clang.llvm.org/docs/ClangFormat.html). The configuration is provided by libgweather itself. Before committing your changes, you should run: ```sh clang-format \ --style=file \ libgweather/*.c \ libgweather/tests/*.c \ libgweather/tools/*.c ``` to ensure that the changes are formatted using the same coding style as the rest of the project. The project's own continuous integration pipeline will enforce the coding style. Once you’ve finished working on the bug fix or feature, push the branch to the Git repository and open a new merge request, to let the libgweather core developers review your contribution. ### Code reviews Each contribution is reviewed by the core developers of the libgweather project. With each code review, we intend to: 0. Identify if this is a desirable change or new feature. Ideally for larger features this will have been discussed (in an issue, on IRC, or on Discourse) already, so that effort isn’t wasted on putting together merge requests which will be rejected. 0. Check the design of any new API. 0. Provide realistic estimates of how long a review might take, if it can’t happen immediately. 0. Ensure that all significant contributions of new code, or bug fixes, are adequately tested, either through requiring tests to be submitted at the same time, or as a follow-up. 0. Ensure that all new APIs are documented and have [introspection annotations](https://gi.readthedocs.org). 0. Check that the contribution is split into logically separate commits, each with a good commit message. 0. Encourage further high quality contributions. 0. Ensure code style and quality is upheld. If a code review is stalled (due to not receiving comments for two or more weeks; or due to a technical disagreement), please ping the libgweather maintainers on the merge request, or on IRC, to ask for a second opinion. ### Commit messages The expected format for git commit messages is as follows: ```plain Short explanation of the commit Longer explanation explaining exactly what’s changed, whether any external or private interfaces changed, what bugs were fixed (with bug tracker reference if applicable) and so forth. Be concise but not too brief. Closes #1234 ``` - Always add a brief description of the commit to the _first_ line of the commit and terminate by two newlines (it will work without the second newline, but that is not nice for the interfaces). - First line (the brief description) must only be one sentence and should start with a capital letter unless it starts with a lowercase symbol or identifier. Don’t use a trailing period either. Don’t exceed 72 characters. - The main description (the body) is normal prose and should use normal punctuation and capital letters where appropriate. Consider the commit message as an email sent to the developers (or yourself, six months down the line) detailing **why** you changed something. There’s no need to specify the **how**: the changes can be inlined. - When committing code on behalf of others use the `--author` option, e.g. `git commit -a --author "Joe Coder "` and `--signoff`. - If your commit is addressing an issue, use the [GitLab syntax](https://docs.gitlab.com/ce/user/project/issues/automatic_issue_closing.html) to automatically close the issue when merging the commit with the upstream repository: ```plain Closes #1234 Fixes #1234 Closes: https://gitlab.gnome.org/GNOME/libgweather/issues/1234 ``` - If you have a merge request with multiple commits and none of them completely fixes an issue, you should add a reference to the issue in the commit message, e.g. `Bug: #1234`, and use the automatic issue closing syntax in the description of the merge request. ### Notes for developers in the GNOME group on GitLab Don't commit any but the most trivial patches without approval. Exceptions to the rule above: - Translators may commit basic i18n related patches to the build setup. - Release team members are welcome to commit merge requests to unbreak the GNOME build. ## Adding new weather sources To add new weather sources, a number of requirements must be considered: - the API should be documented - access to the API can require the use of a freely available application token ID. See the requirements below. - there must not be hard usage limits, or they must be high enough not to cause disruption with weather support being builtin to the OS/desktop - the requests must be made over HTTPS, or an equivalent, encrypted network connection. - the result of requests must be machine parseable, and the parsing code must have unit tests to prevent regressions, and make it easy to root-cause crashes - the user’s privacy must be maintained as much as possible, see section below - the user’s bandwidth must be preserved where possible, with the server offering enough information to avoid downloads through libsoup, our HTTP library. - the data gathered can require a attribution (in which case the patch must contain code to implement this) and if restricted to non-commercial usage, must have a comment mentioning that fact in the GWeatherWeather API documentation - finally, a working and applicable patch must be provided ## Privacy The user’s privacy must be maintained as much as possible: - don’t include unnecessary detail in requests - don’t allow fine-grained location tracking - don’t include other identifying information in the requests if possible - service must have a data usage policy that's reasonable compared to equivalent services, eg. not use requests as a way to feed into user tracking for an advertisment business ## Application token usage Not using tokens is preferable, but some data sources don't offer the option. There are a number of requirements for those tokens: - One should be provided in the patch for testing purposes, and be easily overridable by distributions wishing to have a separate identifier and limits - The test token should have high enough limits that you're reasonably confident that lots of people running `meson test` won’t cause the token to be revoked and break everyone’s tests - Instructions on how to get a token for the application must be provided