fix: use runtime globals in shared plugin

[animecyc]

What kind of change does this PR introduce?

• Fixes a bug that caused HMR to fail when using Module Federation (__webpack_modules__ is not defined).
• Fixes: ConsumeSharedPlugin with HMR throws unexpectedly #12830

Did you add tests for your changes?

I didn't, it would be great if some direction could be given as to where a test for something like this would go. Assuming hotCases?

Does this PR introduce a breaking change?

It doesn't introduce breaking changes.

What needs to be documented once your changes are merged?

This is an internals change, I don't believe this warrants a documentation change.

[webpack-bot]

For maintainers only:

• This needs to be documented (issue in webpack/webpack.js.org will be filed when merged)
• This needs to be backported to webpack 4 (issue will be created when merged)

[sokra]

Changes look good, but we definitely need a test case for the bug

[sokra]

and also make sure to sign the CLA

[sokra]

Yep, a test case in test/hotCases should make it. To trigger the behavior you can add a shared module in a HMR update. Change an existing module to reference the a new shared module.

To trigger both code paths you need on shared module that it loaded with import ... from "shared1" and another one that is loaded with import("shared2").

[animecyc]

and also make sure to sign the CLA

Will do.

Yep, a test case in test/hotCases should make it. To trigger the behavior you can add a shared module in a HMR update. Change an existing module to reference the a new shared module.

To trigger both code paths you need on shared module that it loaded with import ... from "shared1" and another one that is loaded with import("shared2").

I should be able to get something up here in the next few days. Appreciate the direction.

[webpack-bot]

@animecyc Thanks for your update.

I labeled the Pull Request so reviewers will review it again.

@sokra Please review the new changes.

[webpack-bot]

@sokra The most important CI builds failed. This way your PR can't be merged.

Please take a look at the CI results from azure (1 errors / 3 warnings) and appveyor (error) and fix these issues.