Adding to getKeys blocklist

[brettz9]

As per the points raised in #36 by @mdjermanovic , getKeys might be ignoring the following additional properties, with the items in parentheses being relative to ESLint but may call for a major version bump if considering other users:

1. type (perf)
2. range (from BaseNodeWithoutComments) (perf)
3. loc (from SourceLocation) (perf)
4. comments and innerComments (from Comment) (fix since may be mistakenly traversed)

User-facing impact

It is possible some custom AST could be using those properties as legitimate keys, might somehow be (ab)using getKeys to not expect the above properties to be excluded, or might have a traversal function which doesn't ignore those properties when iterating through them.

What is the suggested fix?

However, from the perspective of ESLint, and I think reasonable expectations at least in a major bump, these shouldn't be allowed for traversal given that some are uniformly known not to need traversal given their fixed, special meaning (the perf-labeled items).

For comments and innerComments the case is even stronger to exclude because these will be traversed if present, but as per our prior exclusion of leadingComments and trailingComments, the expectation seems to be not to traverse Comment nodes even if present.

Our new tool to get keys from the TypeScript AST at least does not allow these when building our own key list (by excluding any which lead to Line or Block types), but other tools do not have access to this algorithm when using getKeys().

[nzakas]

Can you expand on this? What is the user-facing impact? What is the suggested fix?

[brettz9]

Can you expand on this? What is the user-facing impact? What is the suggested fix?

I've amended the original message.

[nzakas]

Thanks! 👍

[fasttime]

What exactly is innerComments? I can't find any properties with that name in ESTree or in the eslint org.