Upgrade to Promise-based requirejs

[kirmorozov]

Description (*)

Changes introduce major performance upgrade for Front-end, removes extra computation and timeouts overhead.
These changes are upgrading requirejs internals with requirejs/alameda - Promise-based implementation.
*mostly compatible with original RequireJS.
In this PR incompatible changes are resolved.

Fixed Issues (if relevant)

1. magento/magento2#19470: Debugging of JS issues is painful, upgrade to Promise-based requirejs
2. ...

Manual testing scenarios (*)

Changes must be at low level and compatible with most modules.

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-engcom-team]

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[sivaschenko]

Hi @kirmorozov , thanks for your contribution! For such fundamental changes an architectural approval is required. Can please create a pull request to https://github.com/magento/architecture describing your proposition.

[kirmorozov]

Hi, fellow,
Nothing major.
This is simple replacement, same require(), define() API and polyfill for Promise.
Browser support stays the same, for most APIs.
Plus it is easier to expose dependency tree between modules.

It does not change architecture outside requirejs, and requirejs-related internals.
only 's' property require is going away,
and adding special exposure of queue so mixin.js can mess with it.
Change is so deep, very few engineers will ever get there.

I'll handle issues with tests as soon as reproduce them locally.

[sivaschenko]

Hi @kirmorozov , I mean you are actually updating the library we are relying on lib/web/requirejs/require.js. Such changes should get common attention and approval. That's why I had to ask you to communicate that to https://github.com/magento/architecture

[kirmorozov]

jsbuild is doomed.
Please lets move on with removal of jsbuild-based magento bundles as they are inefficient.
Gulp or Grunt bundling provide uglyfied bundles along with source maps.

[DrewML]

We'll discuss more in the meeting (magento/architecture#47), but regarding the perf comment:

Changes introduce major performance upgrade for Front-end, removes extra computation and timeouts overhead.

Do you have before/after traces you can share? Would be nice to see where the time was being spent.

[sivaschenko]

@magento-engcom-team give me test instance

[magento-engcom-team]

Hi @sivaschenko. Thank you for your request. I'm working on Magento instance for you

[magento-engcom-team]

Hi @sivaschenko, here is your new Magento instance.
Admin access: https://pr-19517.instances.magento-community.engineering/admin
Login: admin Password: 123123q

[kirmorozov]

@magento-engcom-team give me test instance

[magento-engcom-team]

Hi @kirmorozov. Thank you for your request. I'm working on Magento instance for you

[sivaschenko]

Hi @kirmorozov can you please provide benchmark for this pull request as was requested on the architecture discussion meeting

[sidolov]

Hi @kirmorozov , I am closing this PR now due to inactivity.
Please reopen and update if you wish to continue.
Thank you for the collaboration!

[ghost]

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