add storybook ci option to test start-storybook ok

[thedavidprice]

@peterp I'm exploring a way to test storybook server start via E2E.

In this PR, I'm trying the start-storybook --smoke-test (Exit after successful start). Strangely, running it works as described, but it throws with a exit code 1 — seems super unhelpful 🤔:

...
manager (webpack 5.44.0) compiled successfully in 7939 ms
<i> [webpack-dev-middleware] wait until bundle finished: /__webpack_hmr
99% done plugins webpack-hot-middlewarewebpack built preview e0d515b292be71f5422e in 9331ms
WARN preview: [object Object]
error Command failed with exit code 1.

Just running the start-storybook --ci might be another way if we can check the output for Storybook 6.3.6 started . Here's what that looks like:

...
info => Using cached manager
99% done plugins webpack-hot-middlewarewebpack built preview e0d515b292be71f5422e in 9039ms
╭────────────────────────────────────────────────╮
│                                                │
│   Storybook 6.3.6 started                      │
│   9.71 s for preview                           │
│                                                │
│    Local:            http://localhost:7910/    │
│    On your network:  http://192.0.2.2:7910/    │
│                                                │
╰────────────────────────────────────────────────╯
99% done plugins webpack-hot-middlewarewebpack built preview 4a36af37a4de190b352d in 784ms

---

Do you have any other thoughts/suggestions here? Maybe I'm missing something obvious...

[virtuoushub]

fwiw, my suspicion is that somehow the:

WARN preview: [object Object]

results in the non zero exit code.

I have tried start-storybook --smoke-test in repositories I work on that use Storybook, and which I know start and build Storybook. The console output also also had WARN(s) and resulted in:

error Command failed with exit code 1.

I then tried start-storybook --smoke-test from a fresh project ( using getting started ), no WARN and it completed with an exit code of 0.

[thedavidprice]

@virtuoushub Do you want to take over this PR from me? I actually thought that's what you were doing in #3515 No pressure but I'm all for it! Can just close this out.

But also not convinced this is the way to go yet, so understood toward that end as well.

[virtuoushub]

@virtuoushub Do you want to take over this PR from me? I actually thought that's what you were doing in #3515 No pressure but I'm all for it! Can just close this out.

But also not convinced this is the way to go yet, so understood toward that end as well.

Yes I suggest we move over to #3515

I left my comment here earlier because the output stacktrace is in this PR's description, so I thought it made sense just to close the loop about that closer to the context.

If any relevant findings are more in the future I'll drop them in #3515

[thedavidprice]

moved to #3515