Fix Input#origin() mixing null and undefined for unmapped end position#2106
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When the requested end position has no mapping in the source map,
originalPositionFor() returns an object with line/column set to null
rather than omitting them. endLine picked that null up correctly, but
endColumn was computed as `to && to.column + 1`, which due to operator
precedence is `to && (to.column + 1)`, turning null into 1. So callers
could get back { endColumn: 1, endLine: null }, which doesn't match
how every other unmapped case in this function behaves (undefined for
both). Looks like the +1 fix in postcss#2036 covered the mapped case but not
this one.
Guard `to` the same way `from` already is, so an unmapped end position
just stays undefined.
Member
|
Thanks! Do you think we should release it right now or the user case is pretty rare (so we will wait more features to release together)? |
Contributor
Author
|
Up to you — it's not a long-standing bug, more a fresh regression from #2036/8.5.16, so I'd lean toward not sitting on it too long rather than batching it. Whenever a reported range's end falls outside sourcemap coverage, anything reading |
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When the end position passed to
origin()isn't covered by the source map,originalPositionFor()comes back withline/columnset tonullinstead of just not having a mapping.endLineends upnullin that case, butendColumnwas being built asto && to.column + 1, which because of precedence is actuallyto && (to.column + 1), sonullsilently becomes1. You can end up with something like{ endColumn: 1, endLine: null }, which is inconsistent with how the rest of the function treats an unresolved position (both stayundefined).Looks like #2036 fixed the off-by-one for the case where the end position does resolve, but didn't account for it not resolving at all.
Guarded
tothe same wayfromalready is a few lines above, and added a test that reproduces it with a source map that doesn't cover the requested end line.