New transformer to convert ".js" to ".js?f=sxg" in script node values.

[xiexr151e]

This transformer will be used as part of creating the SxG build for AMP, based off of the module build.

[xiexr151e]

@twifkak @erwinmombay

[honeybadgerdontcare]

Is there an issue describing what situation this is addressing?

[xiexr151e]

Is there an issue describing what situation this is addressing?

@honeybadgerdontcare I don't believe so. These are just part of a series of changes needed to make as part of preparing for a SxG build for AMP.

[twifkak]

Thanks for this change! I haven't taken a look at the code in detail yet, but I think a few things need to be done before we can land this PR:

• Serve .sxg.js for v0 and all the extensions at cdn.ampproject.org. (edit: solved with the change to ?f=sxg thought the contents are currently equal)
• Change cdn.ampproject.org cache transformations to rewrite .sxg.js back to .js for serving in AMP Viewer (edit: solved with http://cl/324144375)
• Change validator (either protoascii, or C++&JS) to allow these URLs in transformed AMP (edit: not yet solved)

There are enough users of the master branch that I wouldn't want to introduce a known breakage.

@honeybadgerdontcare @banaag My understanding is that this is the next step in differential loading of JS beyond module/nomodule. They're planning to ship a version of the JS that has viewer integration code and post-module polyfills removed so it has a smaller footprint.

@xiexr151e It might be worth a quick doc to explain the problem/solution. That would more easily allow multiple threads of discussion, and serve as a unified location for the overall plan.

[jridgewell]

Can someone point me to a doc explaining why we need .sxg.js?

[xiexr151e]

@twifkak @honeybadgerdontcare @jridgewell @erwinmombay @kevinkimball
Since we have already discussed this, I've updated the transformer accordingly to reflect our changes. Could you please take another look?

[erwinmombay]

@xiexr151e can you update the subject of this PR as it seems obsolete

[erwinmombay]

also lets externalize our design document and link it here for posterity

[twifkak]

Hi @xiexr151e! Thanks for the updates. Looks like 2 of the 3 blockers are solved, but this is still not valid transformed AMP. Those changes need to be made (and deployed within the Google AMP Cache) before we can merge this. Do you or @erwinmombay own the task of fixing the validator?

[xiexr151e]

Hi @xiexr151e! Thanks for the updates. Looks like 2 of the 3 blockers are solved, but this is still not valid transformed AMP. Those changes need to be made (and deployed within the Google AMP Cache) before we can merge this. Do you or @erwinmombay own the task of fixing the validator?

We jointly own this task, but I will be the primary assignee to the task. We are scheduled to begin the task next week.

[CLAassistant]

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3 out of 5 committers have signed the CLA.

✅ twifkak
✅ banaag
✅ nainar
❌ xiexr151e
❌ Derek Tse

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[erwinmombay]

going to close this. The SxG project is still on going but I will pick it up next quarter. and the code here is already obsolete