jQuery source has been migrated in gh-4541 from AMD to ES modules. To maintain
support for consumers of our AMD modules, this commits adds a task transpiling
the ES modules sources in `src/` to AMD in `amd/`.
A "Load with AMD" checkbox was also restored to the QUnit setup. Note that,
contrary to jQuery 3.x, AMD files need to be generated via `grunt amd` or
`grunt` as sources are not authored in ECMAScript modules. To achieve a similar
no-compile experience during jQuery 4.x testing, use the new "Load as modules"
checkbox which works in all supported browsers except for IE & Edge (the
legacy, EdgeHTML-based one).
Ref gh-4541
Closes gh-4554
Migrate all source AMD modules to ECMAScript modules. The final bundle
is compiled by a custom build process that uses Rollup under the hood.
Test files themselves are still loaded via RequireJS as that has to work in
IE 11.
Tests can now be run in "Load as modules" mode which replaces the previous
"Load with AMD" option. That option of running tests doesn't work in IE
and Edge as it requires support for dynamic imports.
Some of the changes required by the migration:
* check `typeof` of `noGlobal` instead of using the variable directly
as it's not available when modules are used
* change the nonce module to be an object as ECMASscript module exports
are immutable
* remove some unused exports
* import `./core/parseHTML.js` directly in `jquery.js` so that it's not
being cut out when the `ajax` module is excluded in a custom compilation
Closes gh-4541
Tracked bower dependencies are located at "src/sizzle" and "test/libs".
The source-destination mapping is in the Gruntfile.
When updating a bower dependency, update the version in bower.json, run
`grunt bower`, and then commit the result. When adding a dependency,
update the bowercopy task accordingly.
Fixes#14615.
Closes gh-1452.
