Extension API process

Extension API Process

The goal of this process is to be transparent about how API is created, what phases a proposal goes through, and to know what proposals are finalised when. Still, we want to maintain flexibility in making API.

About Proposed API

We work with API proposals on which we iterate a few time before making stable API. Those proposals can be tested by extension authors. This is what you have to do to try out a proposed API:

• You must use Insiders because proposed APIs change frequently.
• You must have this line in the package.json file of your extension: "enableProposedAPI": true.
• Copy the latest version of the vscode.proposed.d.ts-file into your project.

Note that you cannot publish an extension that uses a proposed API. We may likely make breaking changes in the next release and we never want to break existing extensions.

Weekly API call:

• During debt week, everyone that plans to work on API joins the call and presents their case. This call is about forming a shared understanding of the problem and helps us to understand whether the request is one that can safely be mapped onto prior art or will require custom constructs (which pretty much means more work).
• We introduce a ‘api-finalization’ tag on GH to clearly identify the items that are about moving API from proposed to stable.
• Everyone who owns an open ‘api-finalization’ item for the current iteration needs to show up for the API call.
• Everyone who owns an open ‘api-finalization’ item scheduled for the iteration will present in week 1 of the iteration a concrete proposal and sample code showing how the API is being used. The sample code needs to be realistic. One-liners with artificial parameters etc. usually don’t cut it.
• In each API call, we’ll work through the remaining open ‘api-finalization’ items before we look at ‘api-proposal’ items.
• If an API topic needs more time than what we have in the API call, we’ll schedule separate calls for these topics. These calls are open to everyone, just like the API call.

Flow Chart of the Process

Phases of a proposal

1. Idea -> Ask yourself: How does this fit into the existing API? Is this a one-off-API that solves only your one problem? Does this reuse a concept, like providers or commands, or does this add a new concept?
2. Proposal -> Ask yourself: Does my proposal alter existing API and/or violates it our API guidelines?
3. Finalization -> _ Ask yourself:_ Do I have a non-trivial usage-sample for this? Do we use this new API ourselves?