- Remove pdf from webpack.vendor.config
- Support both versions of pdfjs in webpack.constants.js
- Pull pdfjs consts into its own file
- Fix tests

Once a TC39 proposal becomes part of the ECMAScript spec, babel
deprecates the corresponding `@babel/plugin-proposal-*` in favour of a
`@babel/plugin-transform-*`.

We have been enabling a hardcoded list of plugins. Some for
compatibility with webpack@4, some for unknown reasons. We should double
check whether we need them, but that should be done in a separate MR.

That being said, all plugins we use made it to the ECMAScript standard
and we can happily use them as transform plugins.

This rather new setting (ehrm, 3 years old) is well explained in the
release blog post:
https://babeljs.io/blog/2020/03/16/7.9.0#babelpreset-envs-bugfixes-option-11083

In our code base it has the following effect:
1. Safari / Webkit has a bug
   https://bugs.webkit.org/show_bug.cgi?id=220517 related to
   destructuring function arguments.
2. `@babel/preset-env` will turn on `transform-parameters`.
3. With the bugfixes setting enabled, it will turn on
   `bugfix-safari-id-destructuring-collision-in-function-expression`
   instead which only transpiles the specific bug case which we might
   not even have in our code base

Remove istanul pkgs since we dropped karma
long time ago.
Remove @babel/plugin-syntax-import-meta as it's no longer required.

Speciyfing minor version is requried
to tell babel to pull the correct corejs version.

Our version of webpack's acorn is too old and throws errors when we are
not transpiling the optional chaining operators `?.` and nullish
coalescing operators `??` even though all our targeted browsers support
it.

Therefore we need to enable
[`@babel/plugin-proposal-optional-chaining`][0] and
[`@babel/plugin-proposal-nullish-coalescing-operator`][1] manually.

After we have updated to webpack@5, we can disable these plugins.

[0]: https://babeljs.io/docs/en/babel-plugin-proposal-optional-chaining
[1]: https://babeljs.io/docs/en/babel-plugin-proposal-nullish-coalescing-operator

Lukas 'Eipi' Eipert 创作于 4 years ago ，Vitaly Slobodin 提交于 4 years ago

This re-adds our config/, scripts/ and *.config.js files to eslint,
together with some rules to make it a little easier for those
node-scripts, e.g. console logging or importing node or dev dependencies
should be fine.

In order to re-use our browserslist config across babel, autoprefixer
and other tools, we are moving it to a separate file.

Furthermore we update browserslist itself, because why not.

We do not have a fully defined babel preset environment just yet, thus
we go with a bit of conservative values for the other browsers (support
for more versions than necessary) just in order to be safe and until we
have decided on the exact versions to support.

This is a follow-up to [removing most no-op default exports][1]. In that
MR, the "most" was due to the fact that a couple of files were still
participating in Karma tests.

Since it turns out that no Karma tests rely on `babel-plugin-rewire`,
that could be removed, allowing the final two instances of workarounds
for it to be removed as well.

Finally, the `spyOnDependency` helper was removed, since it's unused.

[1]: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/37213

This changes the babel config to allow async/await in jest tests.

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/25964

Removes explict calls to core-js polyfills.
Lets babel find polyfills when needed for our target browsers.

Add babel-lodash for tree shaking
and nice import statements.

This commit is the result of running `yarn eslint --fix` after enabling
the `no-implicit-coercion` ESLint rule.  This rule has been added to
our ESLint config here:

https://gitlab.com/gitlab-org/gitlab-eslint-config/merge_requests/14

With https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25597 we
also removed the babel-plugin-dynamic-import-node. It is now throwing
errors when we run jest with coverage.

This removes other outdated babel@6 dependencies as well.

Unfortunately the newer version of vue-jest has a dependency of an older
version of ts-jest. In order to satisfy the peerDependency from ts-jest,
we are forcing the version@24. The only "breaking" change from ts-jest
23->24 is that it requires a newer version of jest. This might be
obsolete soon, as vue-jest plans on switching to babel eventually.