Ignore silentNever in intersections with other meaningful constituents#60876
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Andarist wants to merge 1 commit intomicrosoft:mainfrom
Open
Ignore silentNever in intersections with other meaningful constituents#60876Andarist wants to merge 1 commit intomicrosoft:mainfrom
silentNever in intersections with other meaningful constituents#60876Andarist wants to merge 1 commit intomicrosoft:mainfrom
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Andarist
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Dec 29, 2024
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| if (type === silentNeverType) { | ||
| return includes; | ||
| } |
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This makes silentNeverType behave more like unknown in intersections. Which is definitely not correct for a never type... but a silentNeverType is really just a special marker type so it doesn't quite have to obey the rules.
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I'm not confident in this at all. I'm treating this as an experiment and I wonder if extended tests can reveal some missing test cases that should be added to the codebase.
The problem is that with a
contextualTypelikeV["someArg"] | ((number | Variable<number, any>) & V["someArg"])whenVgets instantiated withsilentNeverTypethe whole thing becomes... well,silentNeverType. The repro in question is also somewhat interesting because all the involved types come fromV:In the code above
GenericTypegets instantiated withV. In general,GenericTypebit gets converted to its constraint when a contextual type of its~ property is requested. But the mapped type that iterated over stays somewhat deferred asV["someArg"]and further down the line that creates a problem.fixes #60864