Fix crash when creating a union signature from signatures that do and don’t have this types
#31560
Conversation
…nd don’t have this types
| const thisType = getUnionType(map(unionSignatures, sig => sig.thisParameter ? getTypeOfSymbol(sig.thisParameter) : anyType), UnionReduction.Subtype); | ||
| thisParameter = createSymbolWithType(signature.thisParameter!, thisType); | ||
| thisParameter = createSymbolWithType(firstThisParameterOfUnionSignatures, thisType); |
There was a problem hiding this comment.
It feels fairly arbitrary to just pick the first one of these as the source for the new transient symbol, but as far as I can tell it doesn't matter. I thought maybe it would cause an odd behavior for go-to-definition, but then I discovered that go-to-definition on union signatures is already arbitrarily limited to a single signature (#31559), and it doesn't seem to be affected by this change. I briefly experimented with doing a proper merge of every thisParameter symbol, but since I couldn't find any observable effect and go-to-definition on the call expression is already kinda broken, I opted not to use the extra memory and CPU cycles to perform a merge that you probably can't observe anyway. It might be worth revisiting this in #31547 or #31559.
Fixes #31485 but not #31547 since that would be a breaking change