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Remove extra loop (?) #11889

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merged 2 commits into from
Jan 5, 2018
Merged

Remove extra loop (?) #11889

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e70120d
Remove extra loop (?)
jquense Dec 19, 2017
d505081
prettier
jquense Dec 19, 2017
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9 changes: 1 addition & 8 deletions packages/react-dom/src/client/ReactDOMComponentTree.js
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Original file line number Diff line number Diff line change
Expand Up @@ -27,10 +27,7 @@ export function getClosestInstanceFromNode(node) {
return node[internalInstanceKey];
}

// Walk up the tree until we find an ancestor whose instance we have cached.
let parents = [];
while (!node[internalInstanceKey]) {
parents.push(node);
if (node.parentNode) {
node = node.parentNode;
} else {
Expand All @@ -40,17 +37,13 @@ export function getClosestInstanceFromNode(node) {
}
}

let closest;
let inst = node[internalInstanceKey];
if (inst.tag === HostComponent || inst.tag === HostText) {
// In Fiber, this will always be the deepest root.
return inst;
}
for (; node && (inst = node[internalInstanceKey]); node = parents.pop()) {
closest = inst;
}
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I've tried to check back through the history to see what was going on here, and at least originally it used to try and precache nodes: 6d20556#diff-a2fd175216a5aa6425363e6773426f3c

But at some point that was removed but I can't find git blame is not helping :/

Then

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When does line 50 trigger?

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Sorry, I mean like what code path causes closest to be assigned to the instance? And what codepath even lets this function get past return inst on line 47?

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I think in practical usage it doesn't get past 47, but I guess theoretically it could, if the fiber was a different type?

My guess tho is that this was for both stack and fiber and never got removed. Though even if it could get past 47 I don't think the loop does anything other than run one iteration, and return inst

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Cool. I'd love to drop this if the code path no longer fires after Stack's removal. I'm afraid to ping anyone to bug them on holiday, but I think it's worth investigating.

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no rush clearly. :)

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It was hard to find due to a couple project reorganizations nuking the file history, but this was removed in #10798. I think the most likely explanation is that the whole loop could have been removed as well, but it wasn't clear that it was stack-only.

It's a little confusing, but at first glance it seems safe to remove 😄


return closest;
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Does it make sense to return null for invalid fiber types? Maybe it should throw if it's not a HostComponent or HostText? I'm not sure if there are any situations where this should be called with any other type of node.

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that's a good question. I think your probably right, however i was trying to keep with the spirit (for lack of a better term) of the method by failing softly.

I do think tho that a situation where its not a component or text is kind of a different sort of error and maybe should fail hard. Are roots or portals cached on elements? Presumable you should hit a component before that tho

return null;
}

/**
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