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Check combined modifiers in mappedTypeRelatedTo

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This commit is contained in:
Anders Hejlsberg 2017-11-04 08:08:05 -07:00
parent f75a1dce88
commit 45c53e0dcc
1 changed files with 20 additions and 7 deletions
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27
src/compiler/checker.ts
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@ -529,6 +529,11 @@ namespace ts {
Strict,
}
const enum MappedTypeModifiers {
Readonly = 1 << 0,
Optional = 1 << 1,
}
const builtinGlobals = createSymbolTable();
builtinGlobals.set(undefinedSymbol.escapedName, undefinedSymbol);
@ -5875,6 +5880,17 @@ namespace ts {
return type.modifiersType;
}
function getMappedTypeModifiers(type: MappedType): MappedTypeModifiers {
return (type.declaration.readonlyToken ? MappedTypeModifiers.Readonly : 0) |
(type.declaration.questionToken ? MappedTypeModifiers.Optional : 0);
}
function getCombinedMappedTypeModifiers(type: MappedType): MappedTypeModifiers {
const modifiersType = getModifiersTypeFromMappedType(type);
return getMappedTypeModifiers(type) |
(isGenericMappedType(modifiersType) ? getMappedTypeModifiers(<MappedType>modifiersType) : 0);
}
function isPartialMappedType(type: Type) {
return getObjectFlags(type) & ObjectFlags.Mapped && !!(<MappedType>type).declaration.questionToken;
}
@ -9592,13 +9608,10 @@ namespace ts {
// related to Y, where X' is an instantiation of X in which P is replaced with Q. Notice
// that S and T are contra-variant whereas X and Y are co-variant.
function mappedTypeRelatedTo(source: MappedType, target: MappedType, reportErrors: boolean): Ternary {
const sourceReadonly = !!source.declaration.readonlyToken;
const sourceOptional = !!source.declaration.questionToken;
const targetReadonly = !!target.declaration.readonlyToken;
const targetOptional = !!target.declaration.questionToken;
const modifiersRelated = relation === identityRelation ?
sourceReadonly === targetReadonly && sourceOptional === targetOptional :
relation === comparableRelation || !sourceOptional || targetOptional;
const modifiersRelated = relation === comparableRelation || (
relation === identityRelation ? getMappedTypeModifiers(source) === getMappedTypeModifiers(target) :
!(getCombinedMappedTypeModifiers(source) & MappedTypeModifiers.Optional) ||
getCombinedMappedTypeModifiers(target) & MappedTypeModifiers.Optional);
if (modifiersRelated) {
let result: Ternary;
if (result = isRelatedTo(getConstraintTypeFromMappedType(<MappedType>target), getConstraintTypeFromMappedType(<MappedType>source), reportErrors)) {