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Clean up inference of type parameters, contravariant types (#49915)

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This commit is contained in:
Jake Bailey
2022-07-19 15:30:48 -07:00
committed by GitHub
parent 8402d657ab
commit aba867d15a
1 changed files with 26 additions and 18 deletions
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44
src/compiler/checker.ts
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@@ -22562,15 +22562,11 @@ namespace ts {
inferFromTypeArguments(getTypeArguments(source as TypeReference), getTypeArguments(target as TypeReference), getVariances((source as TypeReference).target));
}
else if (source.flags & TypeFlags.Index && target.flags & TypeFlags.Index) {
contravariant = !contravariant;
inferFromTypes((source as IndexType).type, (target as IndexType).type);
contravariant = !contravariant;
inferFromContravariantTypes((source as IndexType).type, (target as IndexType).type);
}
else if ((isLiteralType(source) || source.flags & TypeFlags.String) && target.flags & TypeFlags.Index) {
const empty = createEmptyObjectTypeFromStringLiteral(source);
contravariant = !contravariant;
inferWithPriority(empty, (target as IndexType).type, InferencePriority.LiteralKeyof);
contravariant = !contravariant;
inferFromContravariantTypesWithPriority(empty, (target as IndexType).type, InferencePriority.LiteralKeyof);
}
else if (source.flags & TypeFlags.IndexedAccess && target.flags & TypeFlags.IndexedAccess) {
inferFromTypes((source as IndexedAccessType).objectType, (target as IndexedAccessType).objectType);
@@ -22583,10 +22579,7 @@ namespace ts {
}
else if (source.flags & TypeFlags.Substitution) {
inferFromTypes((source as SubstitutionType).baseType, target);
const oldPriority = priority;
priority |= InferencePriority.SubstituteSource;
inferFromTypes((source as SubstitutionType).substitute, target); // Make substitute inference at a lower priority
priority = oldPriority;
inferWithPriority((source as SubstitutionType).substitute, target, InferencePriority.SubstituteSource); // Make substitute inference at a lower priority
}
else if (target.flags & TypeFlags.Conditional) {
invokeOnce(source, target, inferToConditionalType);
@@ -22637,6 +22630,20 @@ namespace ts {
priority = savePriority;
}
function inferFromContravariantTypesWithPriority(source: Type, target: Type, newPriority: InferencePriority) {
const savePriority = priority;
priority |= newPriority;
inferFromContravariantTypes(source, target);
priority = savePriority;
}
function inferToMultipleTypesWithPriority(source: Type, targets: Type[], targetFlags: TypeFlags, newPriority: InferencePriority) {
const savePriority = priority;
priority |= newPriority;
inferToMultipleTypes(source, targets, targetFlags);
priority = savePriority;
}
function invokeOnce(source: Type, target: Type, action: (source: Type, target: Type) => void) {
const key = source.id + "," + target.id;
const status = visited && visited.get(key);
@@ -22700,10 +22707,14 @@ namespace ts {
}
function inferFromContravariantTypes(source: Type, target: Type) {
contravariant = !contravariant;
inferFromTypes(source, target);
contravariant = !contravariant;
}
function inferFromContravariantTypesIfStrictFunctionTypes(source: Type, target: Type) {
if (strictFunctionTypes || priority & InferencePriority.AlwaysStrict) {
contravariant = !contravariant;
inferFromTypes(source, target);
contravariant = !contravariant;
inferFromContravariantTypes(source, target);
}
else {
inferFromTypes(source, target);
@@ -22866,11 +22877,8 @@ namespace ts {
inferFromTypes(getFalseTypeFromConditionalType(source as ConditionalType), getFalseTypeFromConditionalType(target));
}
else {
const savePriority = priority;
priority |= contravariant ? InferencePriority.ContravariantConditional : 0;
const targetTypes = [getTrueTypeFromConditionalType(target), getFalseTypeFromConditionalType(target)];
inferToMultipleTypes(source, targetTypes, target.flags);
priority = savePriority;
inferToMultipleTypesWithPriority(source, targetTypes, target.flags, contravariant ? InferencePriority.ContravariantConditional : 0);
}
}
@@ -23065,7 +23073,7 @@ namespace ts {
const kind = target.declaration ? target.declaration.kind : SyntaxKind.Unknown;
// Once we descend into a bivariant signature we remain bivariant for all nested inferences
bivariant = bivariant || kind === SyntaxKind.MethodDeclaration || kind === SyntaxKind.MethodSignature || kind === SyntaxKind.Constructor;
applyToParameterTypes(source, target, inferFromContravariantTypes);
applyToParameterTypes(source, target, inferFromContravariantTypesIfStrictFunctionTypes);
bivariant = saveBivariant;
applyToReturnTypes(source, target, inferFromTypes);
}