microsoft/TypeScript
1
0
Fork 0
mirror of https://github.com/microsoft/TypeScript.git synced 2026-02-14 19:16:17 -06:00
Code Issues Packages Projects Releases 212 Wiki Activity

Don't widen undefined types in unions

Browse Source
This commit is contained in:
Anders Hejlsberg 2016-02-15 09:42:16 -08:00
parent f08f6067e8
commit fa36ff85ca
1 changed files with 5 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/compiler/checker.ts
View File

@ -6360,6 +6360,10 @@ namespace ts {
numberIndexInfo && createIndexInfo(getWidenedType(numberIndexInfo.type), numberIndexInfo.isReadonly));
}
function getWidenedConstituentType(type: Type): Type {
return type.flags & TypeFlags.Undefined ? type : getWidenedType(type);
}
function getWidenedType(type: Type): Type {
if (type.flags & TypeFlags.RequiresWidening) {
if (type.flags & TypeFlags.Undefined) {
@ -6372,7 +6376,7 @@ namespace ts {
return getWidenedTypeOfObjectLiteral(type);
}
if (type.flags & TypeFlags.Union) {
return getUnionType(map((<UnionType>type).types, getWidenedType), /*noSubtypeReduction*/ true);
return getUnionType(map((<UnionType>type).types, getWidenedConstituentType), /*noSubtypeReduction*/ true);
}
if (isArrayType(type)) {
return createArrayType(getWidenedType((<TypeReference>type).typeArguments[0]));