feat: introduce tsup for bundling

[weyert]

Added the package tsup to assist in bundling @mswjs/source-package so
it both supports CommonJS and ESM modules. The package.json file has
been modified so the appropriate properties for the modern exports-approach
of exporting, and the older main-module combination.

During building and running the tests the fromOpenApi had issues
to pass the tests or build due to the way the SwaggerParser utility
class was exporter. The code has been updated so it refers to
the deferences-function via SwaggerParser.deferences() instead of trying
to instantiate the class.

For this reason the tsconfig.json has been updated so that it enables
esModuleInterop and allowSyntheticDefaultImports after this change
the package build and bundled successfully with tsup and passed the
unit tests, before errors like below were shown:

    src/fromOpenApi/fromOpenApi.ts:16:35 - error TS2351: This expression is not constructable.
      Type 'typeof SwaggerParser' has no construct signatures.

    16   const specification = await new SwaggerParser().dereference(document)
                                         ~~~~~~~~~~~~~

[weyert]

I have tested these changes by run the build-command and copy the contents of the generated lib-directory to the lib-directory in my project that uses this package and then wrote the following Jest unit test:

import { fromTraffic } from '@mswjs/source'
import { default as json } from './__data__/health-check.json'

  it.only('should throw exception when all services are unavailable', async () => {
    server.use(
      ...fromTraffic(json),
      // rest.get('https://localhost:30001/-/health', (_req, res, _ctx) => {
      //   res.networkError('Network Error')
      // }),
      // rest.get('https://localhost:30002/-/health', (_req, res, _ctx) => {
      //   res.networkError('Network Error')
      // }),
    )

    await expect(controller.check()).rejects.toThrow('Service Unavailable Exception')
  })

For me, after these changes, the above unit test was passing without errors. The project is a Nest.js project using Typescript.

Note I currently don't have a ESM only project ready to test if the ESM module part of the package works as expected. I will try to do make one tomorrow.

[kettanaito]

It'd be great to have automated tests in different formats (CJS/ESM) that help us catch regressions regarding module format incompatibilities.

[kettanaito]

@weyert, I'm sorry, I think I've just messed up the commit authorship after rewording the commit. Could you please git commit --amend --author=X with your proper name + GitHub email? Thanks.

[weyert]

@weyert, I'm sorry, I think I've just messed up the commit authorship after rewording the commit. Could you please git commit --amend --author=X with your proper name + GitHub email? Thanks.

I think I did now but not 100% sure

[weyert]

It'd be great to have automated tests in different formats (CJS/ESM) that help us catch regressions regarding module format incompatibilities.

Yeah, good idea, I am not sure what the best approach is. Maybe a simple script that .mjs (for ESM) and .js (for CJS) then tries to load the package?

[kettanaito]

@weyert, you've set the commit author to @tapico-weyert. If it's the expected result then everything is okay!

[kettanaito]

Released: v0.1.0 🎉

This has been released in v0.1.0!

• 📄 Release notes
• 📦 npm package

Make sure to always update to the latest version (npm i @mswjs/source@latest) to get the newest features and bug fixes.

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