Extensions: update webpack configuration to prevent plugin conflicts

[creativecoder]

Fixes #17289

Changes proposed in this Pull Request:

• Adds a custom setting for output.jsonpFunction to the webpack configuration for building extensions
• This prevents conflicts in the default webpackJsonp JavaScript global when other WordPress plugins also load JavaScript built with webpack

See https://v4.webpack.js.org/configuration/output/#outputjsonpfunction for more information about the webpack configuration.

Jetpack product discussion

N/A

Does this pull request change what data or activity we track or use?

No.

Testing instructions:

I've only been able to replicate #17289 with the release build of Jetpack, not in development environments, so I'm not sure how to test that this definitely fixes the issue.

But more generally, you can test by

1. Build Jetpack extensions with jetpack build plugin and select jetpack.
2. Load a post or page in the editor with your local Jetpack development site. Look at the output JS for extensions (such as editor-beta.js). You should see window["webpackJsonpJetpack"] in the built JS, rather than window["webpackJsonp"]

Proposed changelog entry for your changes:

• Updates the webpack configuration for jsonpFunction when building JavaScript for extensions.

[matticbot]

Caution: This PR has changes that must be merged to WordPress.com
Hello creativecoder! These changes need to be synced to WordPress.com - If you 're an a11n, please commandeer and confirm D50391-code works as expected before merging this PR. Once this PR is merged, please commit the changes to WP.com. Thank you!
This revision will be updated with each commit to this PR

[jetpackbot]

Scheduled Jetpack release: November 10, 2020.
Scheduled code freeze: November 3, 2020

E2E results is available here (for debugging purposes): https://jetpack-e2e-dashboard.herokuapp.com/pr-17312

Thank you for the great PR description!

When this PR is ready for review, please apply the [Status] Needs Review label. If you are an a11n, please have someone from your team review the code if possible. The Jetpack team will also review this PR and merge it to be included in the next Jetpack release.

Generated by 🚫 dangerJS against fc5a9ae

[creativecoder]

Related PR: Automattic/wp-calypso#46252

[creativecoder]

Note that Automattic/wp-calypso#46252 is merged, but the @automattic/calypso-build package still needs a release for the changes to be available through npm.

I've updated the description and marked this ready for review.

[creativecoder]

PR for the update to @automattic/calypso-build

[jeherve]

Noting that we won't be able to update calypso-build just yet, even when a 6.4.0 becomes available. We'll need to fix the issues that prevent us from updating to 6.3.0 first:
#16845

[creativecoder]

Noting that we won't be able to update calypso-build just yet

Ugh.. okay good to know. I'm wondering if we should prioritize that sooner rather than later given the severity of the related bug (#17289)

[jeherve]

yarn link the @automattic/calypso-build package from wp-calypso package you have locally to a local Jetpack development environment

How did you get this to work? I get the following message when I give this a try:

yarn link @automattic/calypso-build
yarn link v1.22.10
error No registered package found called "@automattic/calypso-build".

[creativecoder]

How did you get this to work?

@jeherve my process was

From packages/calypso-build directory in wp-calypso repo, run yarn link (note that you may first need to yarn unlink if you've done this previously). You should see a message

success Registered "@automattic/calypso-build".
info You can now run `yarn link "@automattic/calypso-build"` in the projects where you want to use this package and it will be used instead.

From jetpack repo root, run yarn link "@automattic/calypso-build". You should see

success Using linked package for "@automattic/calypso-build".

[jeherve]

Noting that this will also be fixed in Core, as per this PR:
WordPress/gutenberg#27985

[creativecoder]

Noting that this PR is still blocked by required upgrade of calypso-build. Most recent PR for that upgrade is #19374.

[jeherve]

Noting that this PR is still blocked by required upgrade of calypso-build. Most recent PR for that upgrade is #19374.

The update is now complete. 🎉

[jeherve]

Do you think you could rebase, now that the Calypso build update is merged?

[github-actions]

Thank you for your PR!

When contributing to Jetpack, we have a few suggestions that can help us test and review your patch:

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Then, add the "[Status] Needs Team review" label and ask someone from your team review the code.
Once you’ve done so, switch to the "[Status] Needs Review" label; someone from Jetpack Crew will then review this PR and merge it to be included in the next Jetpack release.

---

Jetpack plugin:

• Next scheduled release: July 6, 2021.
• Scheduled code freeze: June 28, 2021.

[creativecoder]

This should now be ready to go

[anomiex]

Seems ok to me.

PR was rebased.

[github-actions]

Great news! One last step: head over to your WordPress.com diff, D50391-code, and commit it.
Once you've done so, come back to this PR and add a comment with your changeset ID.

Thank you!

[creativecoder]

r227168-wpcom