addition of --env flag to cli-hydrogen preview

[kcarra]

WHY are these changes introduced?

Currently when running shopify hydrogen preview the .env file is not included in the miniflare worker env and Oxygen.env never gets populated with those bindings. This pr adds the --env flag to specify a .env file to be used when creating the preview Oxygen environment. Examples of use:

shopify hydrogen preview --env=.env

shopify hydrogen preview --env=.preview.env

Fixes Shopify/hydrogen/issues/1901

WHAT is this pull request doing?

This pr adds the --env flag to the shopify hydrogen preview command to populate miniflare bindings

How to test your changes?

Vitest:
yarn test packages/cli-hydrogen/src/cli/services/preview.test.ts

yarn link:

• checkout branch
• cd into packages/cli-hydrogen
• yarn yarn link
• cd into a hydrogen project
• yarn link yarn link "@shopify/cli-hydrogen"
• run preview with .env file shopify hydrogen preview --env=.env
• Verify that Oxygen.env is populated with values from .env file

[cartogram]

Thanks for adding tests! Can we add a minor changeset for this?

@rennyG throwing this on your radar for documenting the new flag.

[rennyG]

Thanks for adding tests! Can we add a minor changeset for this?

@rennyG throwing this on your radar for documenting the new flag.

Thanks Matt! I've spun up this issue to address.

[kcarra]

Just signed the CLA as well if you want to re-run the job @cartogram

[rennyG]

What' the delivery by date for the updated docs, @cartogram?

[kcarra]

Thanks for adding tests! Can we add a minor changeset for this?

@rennyG throwing this on your radar for documenting the new flag.

Changeset added

[rennyG]

shopify.dev PR, cc. @cartogram

[pepicrft]

As @matteodepalo pointed out, I'd use the existing utility in @shopify/cli-kit to get the content of the .env file into a Javascript object.

[kcarra]

@matteodepalo @pepicrft @isaacroldan addressed your feedback. Only thing I'm not sure about is why the async version of file.write isn't working in that test. I figured I would toss the question back to you guys for any suggestions before I spend to much time trying to debug it.

[matteodepalo]

@kcarra I think what is happening is that file.write is stubbed so when you try to use it, it doesn't actually do anything. Instead of checking that file.write has been called with certain params, I wonder if we can remove the stub at the top (write: vi.fn()) and replace those checks with actual file.exists and content checks? It would require us to refactor other tests as well, but all those files get deleted anyway because they're written in tmp directories.

You can also try to play with vi.restoreAllMocks at the beginning of the test, although that would restore other mocks as well so it might make other things not work.

[kcarra]

@matteodepalo great ideas! check out 30322d1 vitest allows you to restore your mock to the actual implementation if you pass it as an arg to vi.fn(impl)

[matteodepalo]

@kcarra nice! 👍 approved.

[kcarra]

@blittle @matteodepalo Any idea when this could get merged in?

[matteodepalo]

Merged! Apologies, I think we were waiting on each other to merge :)