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Contribution Guidelines

We welcome many kinds of community contributions to this project! Whether it's a feature implementation, bug fix, or a good idea, please create an issue so that we can discuss it. It is not necessary to create an issue before sending a pull request but it may speed up the process if we can discuss your idea before you start implementing it.

Because this project exposes a couple different public APIs, we must be very mindful of any potential breaking changes. Some contributions may not be accepted if they risk introducing breaking changes or if they don't match the goals of the project. The core maintainer team has the right of final approval over any contribution to this project. However, we are very happy to hear community feedback on any decision so that we can ensure we are solving the right problems in the right way.

Ways to Contribute

  • File a bug or feature request as an issue
  • Comment on existing issues to give your feedback on how they should be fixed/implemented
  • Contribute a bug fix or feature implementation by submitting a pull request
  • Contribute more unit tests for feature areas that lack good coverage
  • Review the pull requests that others submit to ensure they follow established guidelines
  • Help others gets started with the project by contributing documentation or hanging out in the #editors room in the PowerShell community Slack chat.

Code Contribution Guidelines

Here's a high level list of guidelines to follow to ensure your code contribution is accepted:

  • Follow established guidelines for coding style and design
  • Follow established guidelines for commit hygiene
  • Write unit tests to validate new features and bug fixes
  • Ensure that the 'Release' build and unit tests pass locally
  • Ensure that the AppVeyor build passes for your change
  • Respond to all review feedback and final commit cleanup

Practice Good Commit Hygiene

First of all, make sure you are practicing good commit hygiene so that your commits provide a good history of the changes you are making. To be more specific:

  • Write good commit messages

    Commit messages should be clearly written so that a person can look at the commit log and understand how and why a given change was made. Here is a great model commit message taken from a blog post by Tim Pope:

    Capitalized, short (50 chars or less) summary
    
    More detailed explanatory text, if necessary.  Wrap it to about 72
    characters or so.  In some contexts, the first line is treated as the
    subject of an email and the rest of the text as the body.  The blank
    line separating the summary from the body is critical (unless you omit
    the body entirely); tools like rebase can get confused if you run the
    two together.
    
    Write your commit message in the imperative: "Fix bug" and not "Fixed bug"
    or "Fixes bug."  This convention matches up with commit messages generated
    by commands like git merge and git revert.
    
    Further paragraphs come after blank lines.
    
    - Bullet points are okay, too
    
    - Typically a hyphen or asterisk is used for the bullet, followed by a
      single space, with blank lines in between, but conventions vary here
    
    - Use a hanging indent
    

    A change that fixes a known bug with an issue filed should use the proper syntax so that the issue is automatically closed once your change is merged. Here's an example of what such a commit message should look like:

    Fix #3: Catch NullReferenceException from DoThing
    
    This change adds a try/catch block to catch a NullReferenceException that
    gets thrown by DoThing [...]
    
  • Squash your commits

    If you are introducing a new feature but have implemented it over multiple commits, please squash those commits into a single commit that contains all the changes in one place. This especially applies to any "oops" commits where a file is forgotten or a typo is being fixed. Following this approach makes it a lot easier to pull those changes to other branches or roll back the change if necessary.

  • Keep individual commits for larger changes

    You can certainly maintain individual commits for different phases of a big change. For example, if you want to reorganize some files before adding new functionality, have your first commit contain all of the file move changes and then the following commit can have all of the feature additions. We highly recommend this approach so that larger commits don't turn into a jumbled mess.

Add Unit Tests for New Code

If you're adding a new feature to the project, please make sure to include adequate xUnit tests with your change. In this project, we have chosen write out unit tests in a way that uses the actual PowerShell environment rather than extensive interface mocking. This allows us to be sure that our features will work in practice.

We do both component-level and scenario-level testing depending on what code is being tested. We don't expect contributors to test every possible edge case. Testing mainline scenarios and the most common failure scenarios is often good enough.

We are very happy to accept unit test contributions for any feature areas that are more error-prone than others. Also, if you find that a feature fails for you in a specific case, please feel free to file an issue that includes a unit test which reproduces the problem. This will allow us to quickly implement a fix that resolves the problem.

Build 'Release' Before Submitting

Before you send out your pull request, make sure that you have run a Release configuration build of the project and that all new and existing tests are passing. The Release configuration build ensures that all public API interfaces have been documented correctly otherwise it throws an error. We have turned on this check so that our project will always have good generated documentation.

Follow the Pull Request Process

  • Create your pull request

    Use the typical process to send a pull request from your fork of the project. In your pull request message, please give a high-level summary of the changes that you have made so that reviewers understand the intent of the changes. You should receive initial comments within a day or two, but please feel free to ping if things are taking longer than expected.

  • The build and unit tests must run green

    When you submit your pull request, our automated build system on AppVeyor will attempt to run a Release build of your changes and then run all unit tests against the build. If you notice that any of your unit tests have failed, please fix them by creating a new commit and then pushing it to your branch. If you see that some unrelated test has failed, try re-running the build for your pull request. If you continue to see issues, write a comment on the pull request and we will look into it.

  • Respond to code review feedback

    If the reviewers ask you to make changes, make them as a new commit to your branch and push them so that they are made available for a final review pass. Do not rebase the fixes just yet so that the commit hash changes don't upset GitHub's pull request UI.

  • If necessary, do a final rebase

    Once your final changes have been accepted, we may ask you to do a final rebase to have your commits so that they follow our commit guidelines. If specific guidance is given, please follow it when rebasing your commits. Once you do your final push and we see the AppVeyor build pass, we will merge your changes!