ReactJS TypeError: Cannot read property of undefined

Question

I have this code right here, that works in this online text editor: https://codesandbox.io/s/o4n0v203vy

In the npm console, everything is okay:

But in the browser, this happens:

What logs in the console, when i do export var renderTree = (node, setActiveNode, activeNode) => { console.log(node && node.type, 'look here');

I can't figure out why is this happening. Any help is appreciated! Thanks!

You have dummy data in the Codesandbox. Are you using dummy data locally too? If not, please post that data here. — Colin Burke
– Colin Burke, Commented Apr 23, 2018 at 13:42
Try to console the node type export var renderTree = (node, setActiveNode, activeNode) => { console.log(node && node.type, 'look here'); Do you see node type? — Liam
– Liam, Commented Apr 23, 2018 at 13:53

lnl · Accepted Answer · 2018-04-23 13:39:32Z

2

You're probably running the source file in your browser instead of the built one.

answered Apr 23, 2018 at 13:39

lnl

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Comments

Stretch0 · Accepted Answer · 2018-04-23 13:38:37Z

1

The variable node is undefined so doesn't have a property called type.

Change your check to

if(node && node.type === 'file'){
    ...
}

answered Apr 23, 2018 at 13:38

Stretch0

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after applying your solution the error is gone, but the file tree doesn't appear in the browser, which is weird. @Stretch0