Console warnings when using `dcc.Graph` on `dash==1.8` with `debug=True`

[anders-kiaer]

Running some small example like

# -*- coding: utf-8 -*-
import dash
import dash_core_components as dcc
import dash_html_components as html

app = dash.Dash(__name__)

app.layout = html.Div(children=[
    dcc.Graph(
        id='example-graph',
        figure={
            'data': [
                {'x': [1, 2, 3], 'y': [4, 1, 2], 'type': 'bar', 'name': 'SF'},
                {'x': [1, 2, 3], 'y': [2, 4, 5], 'type': 'bar', 'name': u'Montréal'},
            ],
            'layout': {
                'title': 'Dash Data Visualization'
            }
        }
    )
])

if __name__ == '__main__':
    app.run_server(debug=True)

returns console warnings in the browser (Chromium Version 79.0.3945.88):

Warning: Failed prop type: The prop `isRequired` is marked as required in `<<anonymous>>`, but its value is `undefined`.
    in Unknown (created by t)
    in t (created by CheckedComponent)
    in CheckedComponent (created by TreeContainer)
    in UnconnectedComponentErrorBoundary (created by Connect(UnconnectedComponentErrorBoundary))
    in Connect(UnconnectedComponentErrorBoundary) (created by TreeContainer)
    in TreeContainer (created by Connect(TreeContainer))
    in Connect(TreeContainer) (created by TreeContainer)
    in div (created by u)
    in u (created by CheckedComponent)
    in CheckedComponent (created by TreeContainer)
    in UnconnectedComponentErrorBoundary (created by Connect(UnconnectedComponentErrorBoundary))
    in Connect(UnconnectedComponentErrorBoundary) (created by TreeContainer)
    in TreeContainer (created by Connect(TreeContainer))
    in Connect(TreeContainer) (created by UnconnectedContainer)
    in div (created by UnconnectedGlobalErrorContainer)
    in div (created by GlobalErrorOverlay)
    in div (created by GlobalErrorOverlay)
    in GlobalErrorOverlay (created by DebugMenu)
    in div (created by DebugMenu)
    in DebugMenu (created by UnconnectedGlobalErrorContainer)
    in div (created by UnconnectedGlobalErrorContainer)
    in UnconnectedGlobalErrorContainer (created by Connect(UnconnectedGlobalErrorContainer))
    in Connect(UnconnectedGlobalErrorContainer) (created by UnconnectedContainer)
    in UnconnectedContainer (created by Connect(UnconnectedContainer))
    in Connect(UnconnectedContainer) (created by UnconnectedAppContainer)
    in UnconnectedAppContainer (created by Connect(UnconnectedAppContainer))
    in Connect(UnconnectedAppContainer) (created by AppProvider)
    in Provider (created by AppProvider)
    in AppProvider

Appears to happen only when on dash==1.8 and with debug=True. Downgrading to dash==1.7 removes the warning even when debug=True.

dash==1.8.0
dash-core-components==1.7.0
dash-html-components==1.0.2
dash-renderer==1.2.3
dash-table==4.6.0

[alexcjohnson]

Closed by #754