Firefox and WebKit require native promises to provide awaitPromise
functionality. When the Promise is overwritten, all evaluations
in the main world produce wrong Promise, so we wrap with async
function to get a native promise instead.
I enabled vscode autocomplete in our test files. Typechecking had too many errors to enable, but it caught some real bugs that I will fix in a follow up.
This patch contains:
* `test/types.d.ts` - d.ts file for our test runner.
* `test/tsconfig.json` - typescript project for our tests.
* JSDoc header in all specs to mark the describe as a TestSuite
* Drive-by fix of a launcher test that was using `if` instead of `it`
* Some drive-by fixes of unimpactful typos in tests.
