Forbid inferences to conditional type branches at contravariant positions #30287
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@typescript-bot run dt |
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Heya @weswigham, I've started to run the Definitely Typed test suite on this PR at 0268003. You can monitor the build here. It should now contribute to this PR's status checks. |
weswigham
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ahejlsberg
approved these changes
Mar 11, 2019
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Fixes #30057
We'll need to run this on DT to see if it's a bad break - if so, we can probably still make the inferences but at a lower priority (since the issue is that the contravariant inference unifies with a covariant inference and produces a poor result for a lambda) - @ahejlsberg had a distaste for doing so when we spoke of it earlier though, so we're trying this first.