When populating ExportMap, only load file if it's not ignored #1519
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ljharb
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Dec 5, 2019
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I was debugging a project trying to understand better how the
import/no-deprecatedrule works. While doing this I discovered thatExportMap.forwill do a I/O hit to read thepatheven if thepathis ignored:https://github.com/benmosher/eslint-plugin-import/blob/112a0bf442e52b25cd7029a9905df2508e191ac1/src/ExportMap.js#L313-L320
When the
pathis ignored, the function early exits and thecontentvariable is not referenced, so it's essentially a wasted I/O hit.This PR tweaks the condition to do the ignore check in one block, and check ambiguity in another.
In theory this should result in a performance boost for projects that ignore many paths as they will be skipped based off the ignore, rather than being loaded from the file system. It also cleans up the log a little bit because we know exactly why the path was ignored, because of the regex, or because it's ambiguous.