Add support for .ts files when app is not run with ts-node.

[kylerush]

This branch adds support for .ts files when the application is not run with ts-node. The specific use case for this is mentioned in #230. Vitest does not run with ts-node (it uses es-build) to compile TypeScript. This creates a situation where some.ts files that AutoLoad tries to import fails because there is no Typescript transpiler.

This pull request resolves #230.

To make the tests fail

Replace lines 32-42 in test/commonjs/error.js with app3.register(require('./index-error/app')). This will cause the plugin to load ts-node from the Node modules and not throw an error to the user that they need to install ts-node.

Replace index.js with the current version of the file in the master branch. This will cause the test files in test/commonjs/ts-node.js to error because it cannot load .ts files without either being run with ts-node or the ts-node register that is added in this branch.

Notes

I did not modify any documentation as the error messages in index.js will still make sense. Happy to revise the documentation if requested.

Per request, I added vite and vitest as devDependencies and added some vitest tests so that we don't lose vitest support.

Also happy to make any changes needed to this. Thanks for reviewing!

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the [Developer's Certification of Origin]

[mcollina]

Could you add some tests with vitest, so we make sure we do not regress in vitest support?

[kylerush]

Yes, will work on adding some tests with vitest. Good idea.

[kylerush]

@mcollina all set. added some tests with vitest.

[mcollina]

lgtm

[bcomnes]

This change is breaking my non-ts fastify servers #266

[ManUtopiK]

It also not work with vite-node either with vite-plugin-node
with @fastify/autoload": "^5.4.1".
forceESM change nothing.
It always throw this error:

`@fastify/autoload cannot import plugin at '${file}'. To fix this error compile TypeScript to JavaScript or use 'ts-node' to run your app.`

[climba03003]

Please open your own issue with a proper reproducible example.
Different environment require differences fix.