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• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
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• All existing tests are passing: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/DevelopmentWorkflow.md#running-unit-tests-application.
• Tests for the changes are included - https://github.com/NativeScript/NativeScript/blob/master/tools/notes/WritingUnitTests.md.

What is the current behavior?

If there is an attempt to use a plugin dynamic import inside a JavaScript app, one will receive errors about tsconfig.json being missing as webpack will use lazy loading and try to load typescript definition files inside plugin.

Specifically, it occurs when the require path itself is dynamic:

var suffix = "messaging";
import(`firebase-${suffix}`);

Perhaps, this can be solved by creating a tsconfig.json file but the point is that JavaScript apps should not bother with TS files and developers should not worry about TypeScript setup.
Still, plugins include TS definition files and that confuses webpack in NS JavaScript apps.

What is the new behavior?

New behaviour will remove ts-loader if developers declare they use javascript configuration in webpack.

Old webpack plugin excluded ts-loader from webpack.javascript.config file but it seems that webpack5 makes sure most kinds of apps inherit it.