For the best results editing and testing browser compat data, you need the following:
- A familiarity with your terminal and Git (for example, you know how to switch directories, clone a repository, and run scripts)
- A text editor (or editor extension) that supports EditorConfig and the project's
.editorconfigfile - Node.js, with an Active LTS or more recent release
Install the dependencies from npm. From the top-level project directory, run npm install.
Dependencies change from time to time. Periodically re-run npm install to get the latest dependencies.
All data must conform to the schema, plus several additional consistency and style checks. To test your changes locally, run npm test.
For more information on the schema for feature data, see compat-data-schema.md and compat-data.schema.json.
For more information on the schema for browser data, see browsers-schema.md and browsers.schema.json.
To see how changes will affect the statistics of real (either false or a version number, as defined in issue 3555), true, and null values, you can run npm run stats [folder]. This generates a Markdown-formatted table of the percentages of real, true, and null values for the eight primary browsers that browser-compat-data is focusing on. The script also takes an optional argument regarding a specific folder (such as api or javascript), which will print statistics result for only that folder. Additionally, you can run the script with --all to get statistics for all browsers tracked in BCD, not just the primary eight.
To find all the entries that are non-real, or of a specified value, you can run npm run traverse -- [options] [folder].
By default, the script will traverse and print the dotted path to every feature. One or more positional arguments can limit the traversal to a specific folder (for example, api). Additional options can limit the features listed to features with data matching specific browser and version values (for example, --non-real).
Run npm run traverse -- --help for a complete list of options and examples.
The -b or --browser argument may be any browser in the browsers/ folder. This argument may be repeated to traverse multiple browsers. By default, the script will traverse all browsers.
The -f or --filter argument may be any value accepted by version_added or version_removed. This argument may be repeated to test multiple values. By default, the script will traverse all features regardless of their value. The -n or --non-real argument may be included as a convenience alias for -f null -f true.
Examples: to search for all Safari entries that are non-real, run npm run traverse -- -b safari --non-real. To search for all WebView entries that are marked as true in api and javascript, run npm run traverse api,javascript -- -b webview_android -f true. To search for all Firefox entries supported since 10 across all folders, run npm run traverse -- -b firefox -f 10.