Viewport addon hidden by default, does not accept defaultViewport parameter

[Jessidhia]

Describe the bug
@storybook/addon-viewport crashes on initial render, which causes storybooks to render a blank page.

To Reproduce
It seems that all that you need is to specify a defaultViewport:

When it is converted by toList, it splits the string:

When the list is eventually processed, list.map tries to access named properties but the only one that exists is id:

Which eventually crashes inside createItem:

Expected behavior
No crash.

Screenshots
It's a blank page, but I added screenshots of the debugger.

System:

• OS: MacOS
• Device: MBP
• Browser: Chrome
• Framework: Vue
• Addons: viewport
• Version: 5.0.0-rc.6

[Jessidhia]

Likely broken by a86e25f#diff-0b19096a27d5827867e96b205e01a2ffR13 because it treats the string as an object, copying the enumerable properties.

[Jessidhia]

This seems to have been a misconfiguration: https://github.com/storybooks/storybook/tree/next/addons/viewport#change-the-default-viewport

(change from the alphas? or was it just misconfigured all along?)

[Jessidhia]

It seems the deprecation message in configureViewport is misleading, so when the message first appeared it was "fixed" by just directly changing configureViewport(options) to addParameters({ viewports: options }). That didn't crash at first, and only started crashing after the commit that I mentioned.

The Viewport tool also does not render unless it is explicitly configured with addParameters({ viewports: INITIAL_VIEWPORTS }), and choosing the default viewport is buggy (it's hardcoded to 'responsive' on mount, only actually looks for the first viewport with default: true if you change stories).

[shilman]

NOTE: I can repro this in the official storybook in next (5.x) but not in master (4.x)

[tmeasday]

Thanks for the report @Jessidhia.

.addParameters({ viewport: 'string' }) will no longer be supported (we need to it to be an object so it can be sensibly merged by the parameters system) but we need to (a) allow setting the default viewport and (b) not throw up if you do the old thing. See #5829

[shilman]

Yee-haw!! I just released https://github.com/storybooks/storybook/releases/tag/v5.0.0-rc.10 containing PR #5829 that references this issue. Upgrade today to try it out!

Because it's a pre-release you can find it on the @next NPM tag.

Closing this issue. Please re-open if you think there's still more to do.