Check base type for special property declarations #23671
Merged
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If the base type has a property by that name, add it to the list constructor types to make it as authoritative as special assignments found in the constructor.
Before this fix, in JS files with strict null checks on, classes would not check their base types for special declarations -- they would just use the special declarations they found in methods, which incorrectly adds undefined to the type. In the example, below,
Derived
would say that it incorrectly extendsBase
becausep: number | undefined
, when it clearly relies onBase
to initialisep
.Fixes #23628