Ensure all default type params are mapped to some default even in circular scenarios #28423
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weswigham
requested review from
sandersn,
DanielRosenwasser,
ahejlsberg and
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DanielRosenwasser
requested changes
Nov 9, 2018
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@DanielRosenwasser this OK? |
DanielRosenwasser
approved these changes
Nov 12, 2018
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Fixes #28388
In #28222 we started having type parameters have a "base default" of their constraint while we solve for their defaults - however when a type parameter is circularly constrained (we allow this) and circularly defaulted (that we allow this is what caused the last change), this caused uninstantiated parameters to leak into the default. Now we ensure that any references in the constraint to type parameters being default'ed are mapped to the base default type for the context (
{}oranydepending on JS-or-not).