Each child in a list should have a unique "key" prop

[pkuczynski]

I am seeing following warning after adding this plugin:

Warning: Each child in a list should have a unique "key" prop.

Check the top-level render call using <Styled(div)>. See https://fb.me/react-warning-keys for more information.
    in LocalePanel
    in Unknown
    in Unknown
    in Unknown
    in Unknown (created by Context.Consumer)
    in _default (created by Layout)
    in div (created by Context.Consumer)
    in Styled(div) (created by Panel)
    in Panel (created by Layout)
    in div (created by Context.Consumer)
    in Styled(div) (created by Main)
    in div (created by Context.Consumer)
    in Styled(div) (created by Main)
    in Main (created by Layout)
    in Layout (created by Context.Consumer)
    in WithTheme(Layout) (created by ResizeDetector)
    in ResizeDetector
    in div (created by Context.Consumer)
    in Styled(div)
    in Unknown
    in Unknown (created by ResizeDetector)
    in ResizeDetector
    in Unknown
    in Unknown (created by Manager)
    in ThemeProvider (created by Manager)
    in Manager (created by Context.Consumer)
    in Location (created by QueryLocation)
    in QueryLocation (created by Root)
    in LocationProvider (created by Root)
    in HelmetProvider (created by Root)
    in Root

Seems that LocalePanel is part of this library?

[floriangosse]

Which version of React and Storybook do you use?
And which other add-ons have you registered?

[pkuczynski]

    "@storybook/addon-actions": "^5.0.1",
    "@storybook/addon-options": "^5.0.1",
    "@storybook/addons": "^5.0.1",
    "@storybook/react": "^5.0.1",
    "storybook-addon-intl": "^2.4.0",
    "react": "^16.8.4",
    "react-dev-utils": "^8.0.0",
    "react-dom": "^16.8.4",
    "react-intl": "^2.7.2",

[floriangosse]

I might have something to do with storybook@5. I'll need more time to investigate and fix it.

I keep you updated.

[vdh]

It looks like they changed the addon panel rendering in Storybook v5. It was changed in commit storybookjs/storybook@5ecc23e

I couldn't find documentation about the change, but it seemed straightforward enough so I tested a small local patch that looks like it fixed it. I made a PR with the same change.

[floriangosse]

A new version was published which contains the fix for this problem.