This is part of the migration to @web/test-runner, which uses file globs to determine which files should be considered runnable test suites. Changing the file extensions for all test-containing HTML allows them to be distinguished from non-test HTML files (i.e. HTML imports) by path alone. This will also significantly reduce the diff of https://github.com/webcomponents/polyfills/pull/509, within which git is currently struggling to correctly associate files across renames.
This is part of the migration to
@web/test-runner, which uses file globs to determine which files should be considered runnable test suites. Changing the file extensions for all test-containing HTML allows them to be distinguished from non-test HTML files (i.e. HTML imports) by path alone. This will also significantly reduce the diff of https://github.com/webcomponents/polyfills/pull/509, within which git is currently struggling to correctly associate files across renames.