babel-plugin-replace-textdomain: detect aliased imports from the i18n ESM module

[jsnajdr]

Proposed changes

Enhance the babel-plugin-replace-textdomain plugin so that for every function call, it checks if the identifier is coming from the @wordpress/i18n import, even with aliased name:

import { __ as __45 } from '@wordpress/i18n';

__45( 'Sort ascending' );

This "real" name is then checked agains the functions object instead of the alias. Thanks to this, we can reliably detect also the aliased __45 calls, under any name, and can avoid the much less elegant generateI18nVariants helper.

Related product discussion/links

p1774956551856089-slack-C05Q5HSS013

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

No.

Testing instructions

How I tested this:

• cd projects/packages/newsletter (many other packages will do, but I used this one)
• run pnpm build-js
• check the built file in build/newsletter.js and search for Sort ascending. That's a translated string from the dataviews package. Verify that it has domain appended: the call should be __( 'Sort ascending', 'jetpack-newsletter' ).
• if the domain was missing, i.e., the call would be the original __( 'Sort ascending' ), that would mean that the Babel plugin is failing to do its job, no matter the method.

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack or WordPress.com Site Helper), and enable the remove/i18n-alt-names branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack remove/i18n-alt-names

bin/jetpack-downloader test jetpack-mu-wpcom-plugin remove/i18n-alt-names

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• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[github-actions]

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[jp-launch-control]

Code Coverage Summary

Coverage changed in 1 file.

File	Coverage	Δ%	Δ Uncovered
projects/js-packages/babel-plugin-replace-textdomain/src/index.js	70/70 (100.00%)	0.00%	0 💚

Full summary · PHP report · JS report

[anomiex]

I was concerned that this might negatively affect build time, since it's checking the scope of every non-i18n-name call, but some quick tests showed no noticable difference. 👍

[anomiex]

Will this do the right thing for the code path via the true case on line 76? e.g. code like

import { __ as __alias } from '@wordpress/i18n';
someObj.__alias( '???' );

[jsnajdr]

Good catch, this case was indeed buggy. We need an additional check that the callee is not a member expression. Fixed, together with two new unit tests.

[jsnajdr]

I was concerned that this might negatively affect build time, since it's checking the scope of every non-i18n-name call, but some quick tests showed no noticable difference. 👍

Thanks for verifying this. Analyzing the scopes and building the graph is probably already requested by other plugins that are a part of the Babel config, it's a commonly used feature. So there's no extra new work. And the lookups should be fast and cheap.

[anomiex]

I was going to suggest adding something to the readme about support for aliased imports, and when I checked to see what the readme currently says I note that the module isn't really WordPress-specific. It advertises itself as simply handling "gettext-style function calls".

That makes me wonder whether we should make the @wordpress/i18n import name configurable (still defaulting to @wordpress/i18n, of course) in case someone has reason to use a different import. That should be fairly straightforward: check something like opts.i18nmodule, and then pass it through to resolveI18nAlias instead of using a module-global.

OTOH, if you really don't want to, that could be done in a followup PR.