calculator/docs/NewFeatureProcess.md

New feature process

Where do I submit my idea for a new feature?

The easiest way to submit new feature requests is through Feedback Hub. In Feedback Hub, any Windows user (even if they aren't on GitHub) can upvote suggestions. The Calculator team reviews these suggestions regularly, and when we're ready to work on an idea we create feature pitch issues here on GitHub.

But using Feedback Hub is not required—you can create feature pitches too! This document explains the elements of a good pitch and how we'll guide features from a pitch to a finished product. The Feature Tracking board shows all the features we're working on and where they're at in the process.

Do I need to follow this process? Can I just start coding and submit a PR?

You do not need to follow this process for bug fixes, performance improvements, or changes to the development tools. To contribute these changes, discuss the proposed change in an issue and then submit a pull request.

You do need to follow this process for any change which "users will notice". This applies especially to new features and major visual changes.

Step 1: Feature pitch

Feature pitches are submitted as issues on GitHub using the Feature Request template. We encourage discussion on open issues, and as discussion progresses we will edit the issue description to refine the idea until it is ready for review.

We review pitches regularly, and will approve or close issues based on whether they broadly align with the Calculator roadmap. Approved pitches are moved into pre-production on the feature tracking board.

Step 2: Pre-production

For most features, the output of this phase is a specification which describes how the feature will work, supported by design renderings and code prototypes as needed. The original issue will continue to track the overall progress of the feature, but we will create and iterate on spec documentation in the Calculator Spec repo. Sometimes we'll learn new things about a feature proposal during pre-production, and we'll edit or close the original pitch.

We welcome community participation throughout pre-production. The best ideas often come from trying many ideas during the pre-production phase. To enable rapid experimentation, we encourage developing and sharing rough ideas—maybe even with pencil and paper—before making designs pixel-perfect or making code robust and maintainable.

After the spec review is completed, we will move the issue into production on the feature tracking board. In some cases, all of the details of an idea can be captured concisely in original feature pitch. When that happens, we may move ideas directly into production.

Step 3: Production

A feature can be implemented by the original submitter, a Microsoft team member, or by other community members. Code contributions and testing help are greatly appreciated. Please let everyone know if you're actively working on a feature to help avoid duplicated efforts from others.

You might be able to reuse code written during the prototype process, although there will typically be more work required to make the solution robust. Once the code is ready, you can begin submitting pull requests.

Technical review

As with all changes, the code for new features will be reviewed by a member of the Microsoft team before being checked in to the master branch.

New features often need a more thorough technical review than bug fixes. When reviewing code for new features, the Microsoft team considers at least these items:

• All items on the Accessibility checklist should be addressed.
• All items on the Globalization checklist should be addressed.
• The change should be tested on the oldest version of Windows that the app supports. You can find this version number in AppxManifest.xml. Any calls to APIs newer than that version should be conditionally enabled.
• The change should use only supported APIs. If there are any questions about whether legacy or undocumented APIs are in use, the Windows App Certification Kit should be run to check.
• The change should save the user's progress if the app is suspended and resumed. Code to handle these cases should be tested in the Visual Studio debugger.
• If the change has customizations for particular device families, it should be tested on those device families.
• The change should be tested with the app window resized to the smallest possible size.
• The change should be tested with light, dark, and high contrast themes. It should honor the user's preferred accent color.
• If the change adds new libraries or other dependencies:
  • If the library is packaged with the app, the increased size of the binaries should be measured.
  • If the library is not maintained by Microsoft, the Microsoft team will need to set up a plan to monitor the upstream library for changes like security fixes.
  • If the library is being used under an open-source license, we must comply with the license and credit third parties appropriately.
• If the change adds code which runs during the app's startup path, or adds new XAML elements which are loaded at startup:
  • Run the perf tests to measure any increase in startup time. Move work out of the startup path if possible.
• If the change adds additional logging:
  • All logging should use TraceLogging.
  • Unnecessary log events should be removed, or configured so that they are collected only when needed to debug issues or measure feature usage.
• If the change reads user data from files or app settings:
  • Verify that state saved in a previous version of the app can be used with the new version.
• If the change makes network requests:
  • Microsoft must plan to keep these dependencies secure and functional for the lifetime of the app (which might be several years).
  • The app should be fully functional if some network requests are slow or fail. Tools like Fiddler can be used to simulate slow or failed requests.

Step 4: Final product review and merge to master

After the technical review is complete, the product team will review the finished product to make sure the final implementation is ready to release to Windows customers.