Indicating Feature Availability to Tools

Add features to DocC and indicate the feature’s availability to other tools.

Overview

Over time as we develop new features in DocC we also add, update, or remove the flags and options that the docc executable accepts. So that other tools can know what flags and options a certain version of the docc executable accepts, we add new entries in the “features.json” file.

Adding a New Feature

When adding a new collection of command line flags or options to the docc executable that relate to some new feature, add a new entry to the “feature.json” file that name the new feature. For example:

{
  "features": [
    {
      "name": "name-of-first-feature"
    },
    {
      "name": "name-of-second-feature"
    }
  ]
}

Note
Use a single entry for multiple related command line flags and options if they are all added in the same build.

Checking what Features DocC Supports

In a Swift toolchain, the docc executable is installed at usr/bin/docc. In the same toolchain, the “features.json” file is installed at usr/share/docc/features.json.

Tools that call the docc executable from a Swift toolchain can read the “features.json” file to check if a specific feature is available in that build.

Note
The feature entry describes the feature name and doesn’t list what command line flags or options that feature corresponds to.