Missing JS file (critical-css-loader) in Magento 2.3.4

[Sathishkumar8731]

Preconditions (*)

1. Magento 2.3.4
2. MYSQL 5.6
3. PHP 7.2.X

Steps to reproduce (*)

1. Go to the File Path: app/code/Magento/Theme/view/frontend/requirejs-config.js
2. Open the "requirejs-config.js" file and you can find below code in Mapper section

'criticalCssLoader': 'Magento_Theme/js/view/critical-css-loader',

3. Whereas, critical-css-loader js file should be available in the file path: app/code/Magento/Theme/view/frontend/web/js/view

Expected result (*)

1. Loader should need to show while calling criticalcss

Actual result (*)

1. Loader is not working and unable to customize it on Custom them.

[m2-assistant]

Hi @Sathishkumar8731. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

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• Information on your environment
• Steps to reproduce
• Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.4-develop instance - upcoming 2.4.x release

For more details, please, review the Magento Contributor Assistant documentation.

@Sathishkumar8731 do you confirm that you were able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

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[m2-assistant]

Hi @engcom-Bravo. Thank you for working on this issue.
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[magento-engcom-team]

✅ Confirmed by @engcom-Bravo
Thank you for verifying the issue. Based on the provided information internal tickets MC-32088 were created

Issue Available: @engcom-Bravo, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.

[magento-engcom-team]

Hi @Sathishkumar8731. Thank you for your report.
The issue has been fixed in #26987 by @mrtuvn in 2.4-develop branch
Related commit(s):

• e2c403fa3d9fcaa2341214218e35889b4e83b0b8
• eee02627f468d04d24530ddde87ad30f02cee15e
• befbca488671ea50343801ee1232bef4ee066e22
• e22c47c6dce745162a5df8a88873f7f08fb8e290
• a3218fe7b4b8479f1e4ce2d1d5180a80e3245f12
• f98537d818f4dd894a7ba36ef3d56c5865d65ac1
• 339c099c79b183c0a8caca37e2caa8b60d276a49
• 5843df461626ac32230c2425d07f60b480637333
• abad8db69e9b66d8b32be10d38e283c09ebd2d72
• c40d35c9d1de2d1896e2c9a19c18435d2145c5d5
• fb839e740c986c7f52469a566b368eb8bf80e8f3
• e45dd6ee71abfb7b445021281808d86d199cd550
• 5c29e1998e399696046e8562f8ec1a43bfd2ab42

The fix will be available with the upcoming 2.4.0 release.