# Contributing to Zila :balloon: Thanks for your help improving the project! We are so happy to have you! There are opportunities to contribute to Zila at any level. It doesn't matter if you are just getting started with Rust or are the most weathered expert, we can use your help. **No contribution is too small and all contributions are valued.** This guide will help you get started. **Do not let this guide intimidate you**. It should be considered a map to help you navigate the process. ## Conduct The Zila project adheres to the [Rust Code of Conduct][coc]. This describes the _minimum_ behavior expected from all contributors. [coc]: https://github.com/rust-lang/rust/blob/master/CODE_OF_CONDUCT.md ## Contributing in Issues For any issue, there are fundamentally three ways an individual can contribute: 1. By opening the issue for discussion: For instance, if you believe that you have discovered a bug in Zila, creating a new issue in [the a-rustacean/zila issue tracker][issue] is the way to report it. 2. By helping to triage the issue: This can be done by providing supporting details (a test case that demonstrates a bug), providing suggestions on how to address the issue, or ensuring that the issue is tagged correctly. 3. By helping to resolve the issue: Typically this is done either in the form of demonstrating that the issue reported is not a problem after all, or more often, by opening a Pull Request that changes some bit of something in Zila in a concrete and reviewable manner. [issue]: https://github.com/a-rustacean/zila/issues **Anybody can participate in any stage of contribution**. We urge you to participate in the discussion around bugs and participate in reviewing PRs. ### Asking for General Help If you have reviewed existing documentation and still have questions or are having problems, you can [open a discussion] asking for help. In exchange for receiving help, we ask that you contribute back a documentation PR that helps others avoid the problems that you encountered. [open a discussion]: https://github.com/a-rustacean/zila/discussions/new ### Submitting a Bug Report When opening a new issue in the Zila issue tracker, you will be presented with a basic template that should be filled in. If you believe that you have uncovered a bug, please fill out this form, following the template to the best of your ability. Do not worry if you cannot answer every detail, just fill in what you can. The two most important pieces of information we need in order to properly evaluate the report is a description of the behavior you are seeing and a simple test case we can use to recreate the problem on our own. If we cannot recreate the issue, it becomes impossible for us to fix. In order to rule out the possibility of bugs introduced by userland code, test cases should be limited, as much as possible, to using only Zila APIs. See [How to create a Minimal, Complete, and Verifiable example][mcve]. [mcve]: https://stackoverflow.com/help/mcve ### Triaging a Bug Report Once an issue has been opened, it is not uncommon for there to be discussion around it. Some contributors may have differing opinions about the issue, including whether the behavior being seen is a bug or a feature. This discussion is part of the process and should be kept focused, helpful, and professional. Short, clipped responses—that provide neither additional context nor supporting detail—are not helpful or professional. To many, such responses are simply annoying and unfriendly. Contributors are encouraged to help one another make forward progress as much as possible, empowering one another to solve issues collaboratively. If you choose to comment on an issue that you feel either is not a problem that needs to be fixed, or if you encounter information in an issue that you feel is incorrect, explain why you feel that way with additional supporting context, and be willing to be convinced that you may be wrong. By doing so, we can often reach the correct outcome much faster. ### Resolving a Bug Report In the majority of cases, issues are resolved by opening a Pull Request. The process for opening and reviewing a Pull Request is similar to that of opening and triaging issues, but carries with it a necessary review and approval workflow that ensures that the proposed changes meet the minimal quality and functional guidelines of the Zila project. ## Pull Requests Pull Requests are the way concrete changes are made to the code, documentation, and dependencies in the Zila repository. Even tiny pull requests (e.g., one character pull request fixing a typo in API documentation) are greatly appreciated. Before making a large change, it is usually a good idea to first open an issue describing the change to solicit feedback and guidance. This will increase the likelihood of the PR getting merged. ### Tests If the change being proposed alters code (as opposed to only documentation for example), it is either adding new functionality to Zila or it is fixing existing, broken functionality. In both of these cases, the pull request should include one or more tests to ensure that Zila does not regress in the future. There are two ways to write tests: [integration tests][integration-tests] and [documentation tests][documentation-tests]. (Zila avoids [unit tests][unit-tests] as much as possible). ### Commits It is a recommended best practice to keep your changes as logically grouped as possible within individual commits. There is no limit to the number of commits any single Pull Request may have, and many contributors find it easier to review changes that are split across multiple commits. That said, if you have a number of commits that are "checkpoints" and don't represent a single logical change, please squash those together. Note that multiple commits often get squashed when they are landed (see the notes about [commit squashing](#commit-squashing)). #### Commit message guidelines A good commit message should describe what changed and why. 1. The first line should: * contain a short description of the change (preferably 50 characters or less, and no more than 72 characters) * be entirely in lowercase with the exception of proper nouns, acronyms, and the words that refer to code, like function/variable names * be prefixed with the name of the sub crate being changed. Examples: * timer: introduce `Timeout` and deprecate `Deadline` * export `Encoder`, `Decoder`, `Framed*` from codec 2. Keep the second line blank. 3. Wrap all other lines at 72 columns (except for long URLs). 4. If your patch fixes an open issue, you can add a reference to it at the end of the log. Use the `Fixes: #` prefix and the issue number. For other references use `Refs: #`. `Refs` may include multiple issues, separated by a comma. Examples: - `Fixes: #1337` - `Refs: #1234` Sample complete commit message: ```txt subcrate: explain the commit in one line Body of commit message is a few lines of text, explaining things in more detail, possibly giving some background about the issue being fixed, etc. The body of the commit message can be several paragraphs, and please do proper word-wrap and keep columns shorter than about 72 characters or so. That way, `git log` will show things nicely even when it is indented. Fixes: #1337 Refs: #453, #154 ``` ### Opening the Pull Request From within GitHub, opening a new Pull Request will present you with a [template] that should be filled out. Please try to do your best at filling out the details, but feel free to skip parts if you're not sure what to put. [template]: .github/PULL_REQUEST_TEMPLATE.md ### Discuss and update You will probably get feedback or requests for changes to your Pull Request. This is a big part of the submission process so don't be discouraged! Some contributors may sign off on the Pull Request right away, others may have more detailed comments or feedback. This is a necessary part of the process in order to evaluate whether the changes are correct and necessary. **Any community member can review a PR and you might get conflicting feedback**. Keep an eye out for comments from code owners to provide guidance on conflicting feedback. **Once the PR is open, do not rebase the commits**. See [Commit Squashing](#commit-squashing) for more details. ### Commit Squashing In most cases, **do not squash commits that you add to your Pull Request during the review process**. When the commits in your Pull Request land, they may be squashed into one commit per logical change. Metadata will be added to the commit message (including links to the Pull Request, links to relevant issues, and the names of the reviewers). The commit history of your Pull Request, however, will stay intact on the Pull Request page. ## Reviewing Pull Requests **Any Zila community member is welcome to review any pull request**. All Zila contributors who choose to review and provide feedback on Pull Requests have a responsibility to both the project and the individual making the contribution. Reviews and feedback must be helpful, insightful, and geared towards improving the contribution as opposed to simply blocking it. If there are reasons why you feel the PR should not land, explain what those are. Do not expect to be able to block a Pull Request from advancing simply because you say "No" without giving an explanation. Be open to having your mind changed. Be open to working with the contributor to make the Pull Request better. Reviews that are dismissive or disrespectful of the contributor or any other reviewers are strictly counter to the Code of Conduct. When reviewing a Pull Request, the primary goals are for the codebase to improve and for the person submitting the request to succeed. **Even if a Pull Request does not land, the submitters should come away from the experience feeling like their effort was not wasted or unappreciated**. Every Pull Request from a new contributor is an opportunity to grow the community. ### Review a bit at a time. Do not overwhelm new contributors. It is tempting to micro-optimize and make everything about relative performance, perfect grammar, or exact style matches. Do not succumb to that temptation. Focus first on the most significant aspects of the change: 1. Does this change make sense for Zila? 2. Does this change make Zila better, even if only incrementally? 3. Are there clear bugs or larger scale issues that need attending to? 4. Is the commit message readable and correct? If it contains a breaking change is it clear enough? Note that only **incremental** improvement is needed to land a PR. This means that the PR does not need to be perfect, only better than the status quo. Follow up PRs may be opened to continue iterating. When changes are necessary, *request* them, do not *demand* them, and **do not assume that the submitter already knows how to add a test or run a benchmark**. Specific performance optimization techniques, coding styles and conventions change over time. The first impression you give to a new contributor never does. Nits (requests for small changes that are not essential) are fine, but try to avoid stalling the Pull Request. Most nits can typically be fixed by the Zila Collaborator landing the Pull Request but they can also be an opportunity for the contributor to learn a bit more about the project. It is always good to clearly indicate nits when you comment: e.g. `Nit: change foo() to bar(). But this is not blocking.` If your comments were addressed but were not folded automatically after new commits or if they proved to be mistaken, please, [hide them][hiding-a-comment] with the appropriate reason to keep the conversation flow concise and relevant. ### Be aware of the person behind the code Be aware that *how* you communicate requests and reviews in your feedback can have a significant impact on the success of the Pull Request. Yes, we may land a particular change that makes Zila better, but the individual might just not want to have anything to do with Zila ever again. The goal is not just having good code. ### Abandoned or Stalled Pull Requests If a Pull Request appears to be abandoned or stalled, it is polite to first check with the contributor to see if they intend to continue the work before checking if they would mind if you took it over (especially if it just has nits left). When doing so, it is courteous to give the original contributor credit for the work they started (either by preserving their name and email address in the commit log, or by using an `Author: ` meta-data tag in the commit. _Adapted from the [Node.js contributing guide][node]_. [node]: https://github.com/nodejs/node/blob/master/CONTRIBUTING.md [hiding-a-comment]: https://help.github.com/articles/managing-disruptive-comments/#hiding-a-comment [documentation test]: https://doc.rust-lang.org/rustdoc/documentation-tests.html ## Keeping track of issues and PRs The Zila GitHub repository has a lot of issues and PRs to keep track of. This section explains the meaning of various labels. The section is primarily targeted at maintainers. Most contributors aren't able to set these labels. ### Category - **C-bug** This is a bug-report. Bug-fix PRs use `C-enhancement` instead. - **C-enhancement** This is a PR that adds a new features. - **C-maintenance** This is an issue or PR about stuff such as documentation, GitHub Actions or code quality. - **C-feature-request** This is a feature request. Implementations of feature requests use `C-enhancement` instead. - **C-feature-accepted** If you submit a PR for this feature request, we wont close it with the reason "we don't want this". Issues with this label should also have the `C-feature-request` label. - **C-musing** Stuff like tracking issues or roadmaps. "musings about a better world" - **C-proposal** A proposal of some kind, and a request for comments. - **C-question** A user question. Large overlap with GitHub discussions. - **C-request** A non-feature request, e.g. "please add deprecation notices to `-alpha.*` versions of crates" ### Calls for participation - **E-help-wanted** Stuff where we want help. Often seen together with `C-bug` or `C-feature-accepted`. - **E-easy** This is easy, ranging from quick documentation fixes to stuff you can do after reading the tutorial on our website. - **E-medium** This is not `E-easy` or `E-hard`. - **E-hard** This either involves very tricky code, is something we don't know how to solve, or is difficult for some other reason. - **E-needs-mvce** This bug is missing a minimal complete and verifiable example. The "E-" prefix is the same as used in the Rust compiler repository. Some issues are missing a difficulty rating, but feel free to ask on our Discord server if you want to know how difficult an issue likely is. ### Topic Some extra information. - **T-docs** This is about documentation. - **T-performance** This is about performance. - **T-v0.1.x** This is about old Zila. Any label not listed here is not in active use. ## LTS guarantees Zila ≥1.0.0 comes with LTS guarantees: * A minimum of 5 years of maintenance. * A minimum of 3 years before a hypothetical 2.0 release. The goal of these guarantees is to provide stability to the ecosystem. ## Minimum Supported Rust Version (MSRV) * All Zila ≥1.0.0 releases will support at least a 6-month old Rust compiler release. * The MSRV will only be increased on 1.x releases. ## Versioning Policy With Zila ≥1.0.0: * Patch (1.\_.x) releases _should only_ contain bug fixes or documentation changes. Besides this, these releases should not substantially change runtime behavior. * Minor (1.x) releases may contain new functionality, MSRV increases (see above), minor dependency updates, deprecations, and larger internal implementation changes. This is as defined by [Semantic Versioning 2.0](https://semver.org/). ## Releasing Since the Zila project consists of a number of crates, many of which depend on each other, releasing new versions to crates.io can involve some complexities. When releasing a new version of a crate, follow these steps: 1. **Ensure that the release crate has no path dependencies.** When the HEAD version of a Zila crate requires unreleased changes in another Zila crate, the crates.io dependency on the second crate will be replaced with a path dependency. Crates with path dependencies cannot be published, so before publishing the dependent crate, any path dependencies must also be published. This should be done through a form of depth-first tree traversal: 1. Starting with the first path dependency in the crate to be released, inspect the `Cargo.toml` for the dependency. If the dependency has any path dependencies of its own, repeat this step with the first such dependency. 2. Begin the release process for the path dependency. 3. Once the path dependency has been published to crates.io, update the dependent crate to depend on the crates.io version. 4. When all path dependencies have been published, the dependent crate may be published. To verify that a crate is ready to publish, run: ```bash bin/publish --dry-run ``` 2. **Update Cargo metadata.** After releasing any path dependencies, update the `version` field in `Cargo.toml` to the new version, and the `documentation` field to the docs.rs URL of the new version. 3. **Update other documentation links.** Update the "Documentation" link in the crate's `README.md` to point to the docs.rs URL of the new version. 4. **Update the changelog for the crate.** Each crate in the Zila repository has its own `CHANGELOG.md` in that crate's subdirectory. Any changes to that crate since the last release should be added to the changelog. Change descriptions may be taken from the Git history, but should be edited to ensure a consistent format, based on [Keep A Changelog][keep-a-changelog]. Other entries in that crate's changelog may also be used for reference. 5. **Perform a final audit for breaking changes.** Compare the HEAD version of crate with the Git tag for the most recent release version. If there are any breaking API changes, determine if those changes can be made without breaking existing APIs. If so, resolve those issues. Otherwise, if it is necessary to make a breaking release, update the version numbers to reflect this. 6. **Open a pull request with your changes.** Once that pull request has been approved by a maintainer and the pull request has been merged, continue to the next step. 7. **Release the crate.** Run the following command: ```bash bin/publish ``` Your editor and prompt you to edit a message for the tag. Copy the changelog entry for that release version into your editor and close the window. [keep-a-changelog]: https://github.com/olivierlacan/keep-a-changelog/blob/master/CHANGELOG.md [unit-tests]: https://doc.rust-lang.org/rust-by-example/testing/unit_testing.html [integration-tests]: https://doc.rust-lang.org/rust-by-example/testing/integration_testing.html [documentation-tests]: https://doc.rust-lang.org/rust-by-example/testing/doc_testing.html [conditional-compilation]: https://doc.rust-lang.org/reference/conditional-compilation.html