This fix looks good and we can move it up within this function where we skip a given slot if it doesn't represent a node that requires annotations, i.e. we can extend this condition with an extra check:

    if (!isTNodeShape(tNode)) {
      continue;
    }

to

    if (!isTNodeShape(tNode) || isLetDeclaration(tNode)) {
      continue;
    }

(there is also a comment above this check that would require an update)

I'm not sure the change you're suggesting is correct. The condition after this else if is handling let declarations specifically.

@JeanMeche thanks for additional info. The fix looks good, but we should probably look into that a bit more to make sure that we don't generate an extra annotations for nodes that follow @let, e.g. for this situation we do not want to generate extra info in nghData for <div>:

@let name = 'Andrew';
<div>Hi {{ name }}!</div>

I believe the code in the else if block that you've mentioned would add extra annotation.

If you get a chance, could you please compare what we have in the nghData object for the mentioned template vs when @let is not present?

There is an extra entry in the NODES when there is a @let declared. But it looks like they are required (not having them breaks hydration in our unit tests). Maybe @crisbeto can chime in on this.

According to the current logic they are required, but we can update the logic within the locateNextRNode function to skip over LetDeclaration TNodes instead, so adding extra paths to the NODES set would not be required (+ also doing extra DOM "walks" to find those elements). Note: no need to block this PR, we can explore this more as a followup.