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Merge pull request #19741 from Microsoft/fixMappedTypeModifiers

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Check combined mapped type modifiers
This commit is contained in:
Anders Hejlsberg
2017-11-06 09:35:28 -08:00
committed by GitHub
parent 0a7b7e07ee 9619dc14f9
commit 8d991f70b3
6 changed files with 821 additions and 7 deletions
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27
src/compiler/checker.ts
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@@ -520,6 +520,11 @@ namespace ts {
Strict,
}
const enum MappedTypeModifiers {
Readonly = 1 << 0,
Optional = 1 << 1,
}
const builtinGlobals = createSymbolTable();
builtinGlobals.set(undefinedSymbol.escapedName, undefinedSymbol);
@@ -5866,6 +5871,17 @@ 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;
}
@@ -9583,13 +9599,10 @@ 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)) {