🏗 Share dependencies in bento.js

[alanorozco]

Partial for #36421

bento-*.js files now use shared modules from a global BENTO.

Shared modules are listed on shared-bento-symbols.js.

• We generate bento.js to import and provide the dependencies based on this list. We also generate bento-shared.js to use the dependencies from the global.

• bento-*.js binaries use module-resolver so that the listed imports are replaced with bento-shared.js.

Also adds the flag --bento_runtime_only.

[amp-owners-bot]

Hey @erwinmombay, @jridgewell! These files were changed:

build-system/babel-plugins/babel-plugin-bento-imports/index.js
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/ignored/input.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/ignored/output.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/local-name/input.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/local-name/output.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/mixed/input.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/mixed/output.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/namespace/input.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/namespace/output.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/options.json
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/preserved/input.mjs
build-system/babel-plugins/babel-plugin-bento-imports/test/fixtures/transform-assertions/preserved/output.mjs
+1 more

[samouri]

Did we ever discuss why we are pursuing this approach vs. the naive way?

My impression is that naively we could manually add all of the imports into bento.js like so:

// bento.js
import {PreactBaseElement} from '#preact/base-element';
window.BENTO['PreactBaseElement'] = PreactBaseElement;

// amp-fit-text/1.0/base-element.js
class FitText extends window.BENTO.PreactBaseElement {
 ...
}

I think what you've written in this PR is a babel transform which automatically performs the same translation right? That means we don't need to modify the source and can easily update which modules are included in bento.js over time.

[alanorozco]

@samouri

• Adding them to bento.js source manually would be fine, just somewhat tedious.
• The AMP layer bundles the dependencies, so we can't change the extension source to use self.BENTO.
• We can get rid of the transform if we restructure the packages so they only include what we'd like share. If so, we can use an early module-resolver

[samouri]

@alanorozco: are there any blockers for this PR?