microsoft/TypeScript
1
0
Fork 0
mirror of https://github.com/microsoft/TypeScript.git synced 2026-02-11 01:34:55 -06:00
Code Issues Packages Projects Releases 212 Wiki Activity

Merge pull request #22281 from Microsoft/noNeverTypePropagation

Browse Source 
Don't propagate 'never' types in type inference
This commit is contained in:
Anders Hejlsberg 2018-03-01 16:38:32 -08:00 committed by GitHub
commit f6418c0d30
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/compiler/checker.ts
View File

@ -11525,10 +11525,10 @@ namespace ts {
if (!couldContainTypeVariables(target)) {
return;
}
if (source.flags & (TypeFlags.Any | TypeFlags.Never) && source !== silentNeverType) {
// We are inferring from 'any' or 'never'. We want to infer this type for every type parameter
// referenced in the target type, so we record the propagation type and infer from the target
// to itself. Then, as we find candidates we substitute the propagation type.
if (source.flags & TypeFlags.Any) {
// We are inferring from an 'any' type. We want to infer this type for every type parameter
// referenced in the target type, so we record it as the propagation type and infer from the
// target to itself. Then, as we find candidates we substitute the propagation type.
const savePropagationType = propagationType;
propagationType = source;
inferFromTypes(target, target);