JavaScript: Improve CFG for non-toplevel imports #275
Merged
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This is a non-standard language feature for which we have parser support. Previously, however, the CFG extractor and the QL library still assumed that all imports appear at the toplevel, which gave us strange results for example on meteor.
This PR updates the QL library to remove the assumption about imports being top-level. Furthermore, we patch the missing CFG edges for non-toplevel imports in the library. I will open an internal PR that teaches the extractor to add these edges to begin with. The QL-level patch is compatible with the extractor changes, so having either or both of them works, and consequently we can deal with the PRs independently.
I have verified that this removes the false positives on meteor and doesn't otherwise affect results, at a very moderate cost to performance (<5%, so probably within the margin of error).