microsoft/TypeScript
1
0
Fork 0
mirror of https://github.com/microsoft/TypeScript.git synced 2026-05-15 12:51:30 -05:00
Code Issues Packages Projects Releases 212 Wiki Activity

Merge pull request #5459 from Microsoft/partialSignatureMatching

Browse Source 
Fix union type partial signature matching
This commit is contained in:
Anders Hejlsberg
2015-11-05 16:46:52 -08:00
parent 12c6a7400d 31331ff6d1
commit 9b4956fa11
4 changed files with 132 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
src/compiler/checker.ts
View File

@@ -5606,18 +5606,31 @@ namespace ts {
return compareTypes(getTypeOfSymbol(sourceProp), getTypeOfSymbol(targetProp));
}
function isMatchingSignature(source: Signature, target: Signature, partialMatch: boolean) {
// A source signature matches a target signature if the two signatures have the same number of required,
// optional, and rest parameters.
if (source.parameters.length === target.parameters.length &&
source.minArgumentCount === target.minArgumentCount &&
source.hasRestParameter === target.hasRestParameter) {
return true;
}
// A source signature partially matches a target signature if the target signature has no fewer required
// parameters and no more overall parameters than the source signature (where a signature with a rest
// parameter is always considered to have more overall parameters than one without).
if (partialMatch && source.minArgumentCount <= target.minArgumentCount && (
source.hasRestParameter && !target.hasRestParameter ||
source.hasRestParameter === target.hasRestParameter && source.parameters.length >= target.parameters.length)) {
return true;
}
return false;
}
function compareSignatures(source: Signature, target: Signature, partialMatch: boolean, ignoreReturnTypes: boolean, compareTypes: (s: Type, t: Type) => Ternary): Ternary {
if (source === target) {
return Ternary.True;
}
if (source.parameters.length !== target.parameters.length ||
source.minArgumentCount !== target.minArgumentCount ||
source.hasRestParameter !== target.hasRestParameter) {
if (!partialMatch ||
source.parameters.length < target.parameters.length && !source.hasRestParameter ||
source.minArgumentCount > target.minArgumentCount) {
return Ternary.False;
}
if (!(isMatchingSignature(source, target, partialMatch))) {
return Ternary.False;
}
let result = Ternary.True;
if (source.typeParameters && target.typeParameters) {