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Conservative inspection of type annotations to avoid circularities

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This commit is contained in:
Anders Hejlsberg 2020-02-07 17:12:52 -08:00
parent 14789bab03
commit ef939c5388
1 changed files with 37 additions and 2 deletions
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39
src/compiler/checker.ts
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@ -12210,8 +12210,7 @@ namespace ts {
}
for (const props of arrayFrom(members.values())) {
if (isArray(props)) {
const types = map(props, getTypeOfSymbol);
if (every(types, isLiteralType) && getIntersectionType(types).flags & TypeFlags.Never) {
if (every(props, hasLiteralLikeTypeAnnotation) && getIntersectionType(map(props, getTypeOfSymbol)).flags & TypeFlags.Never) {
return true;
}
}
@ -12219,6 +12218,42 @@ namespace ts {
return false;
}
function hasLiteralLikeTypeAnnotation(prop: Symbol) {
if (prop.valueDeclaration) {
const node = getEffectiveTypeAnnotationNode(prop.valueDeclaration);
return !!node && isLiteralLikeType(node);
}
return false;
}
function isLiteralLikeType(node: TypeNode): boolean {
switch (node.kind) {
case SyntaxKind.LiteralType:
return true;
case SyntaxKind.ParenthesizedType:
return isLiteralLikeType((<ParenthesizedTypeNode>node).type);
case SyntaxKind.UnionType:
return every((<UnionTypeNode>node).types, isLiteralLikeType);
case SyntaxKind.TypeReference:
return isReferenceToLiteralLikeType(<TypeReferenceNode>node);
}
return false;
}
function isReferenceToLiteralLikeType(node: TypeReferenceNode): boolean {
const symbol = resolveTypeReferenceName(node.typeName, SymbolFlags.Type);
if (symbol.flags & (SymbolFlags.Enum | SymbolFlags.EnumMember)) {
return true;
}
if (symbol.flags & SymbolFlags.TypeAlias) {
const declaration = find(symbol.declarations, isTypeAliasDeclaration);
if (declaration) {
return isLiteralLikeType(declaration.type);
}
}
return false;
}
function getTypeFromIntersectionTypeNode(node: IntersectionTypeNode): Type {
const links = getNodeLinks(node);
if (!links.resolvedType) {