Strengthen supertype reduction check to reduce breakage

microsoft · Mar 26, 2019 · d5f32bd · d5f32bd
1 parent cbbbda4
commit d5f32bd
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Showing 5 changed files with 3 additions and 178 deletions.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -11181,7 +11181,7 @@ namespace ts {
                 }
                 else {
                     const sub = instantiateType((<SubstitutionType>type).substitute, mapper);
-                    if (sub.flags & TypeFlags.AnyOrUnknown || isTypeSubtypeOf(maybeVariable, sub)) {
+                    if (sub.flags & TypeFlags.AnyOrUnknown || isTypeSubtypeOf(getRestrictiveInstantiation(maybeVariable), getRestrictiveInstantiation(sub))) {
                         return maybeVariable;
                     }
                     return sub;

diff --git a/...rcularlyConstrainedMappedTypeContainingConditionalNoInfiniteInstantiationDepth.errors.txt b/...rcularlyConstrainedMappedTypeContainingConditionalNoInfiniteInstantiationDepth.errors.txt
diff --git a/...ce/circularlyConstrainedMappedTypeContainingConditionalNoInfiniteInstantiationDepth.types b/...ce/circularlyConstrainedMappedTypeContainingConditionalNoInfiniteInstantiationDepth.types
@@ -79,7 +79,7 @@ type ComponentType<P = {}> = ComponentClass<P> | FunctionComponent<P>;
 >ComponentType : ComponentType<P>
 
 export type Shared<
->Shared : any
+>Shared : Shared<InjectedProps, DecorationTargetProps>
 
     InjectedProps,
     DecorationTargetProps extends Shared<InjectedProps, DecorationTargetProps>

diff --git a/tests/baselines/reference/circularlySimplifyingConditionalTypesNoCrash.errors.txt b/tests/baselines/reference/circularlySimplifyingConditionalTypesNoCrash.errors.txt
diff --git a/tests/baselines/reference/circularlySimplifyingConditionalTypesNoCrash.types b/tests/baselines/reference/circularlySimplifyingConditionalTypesNoCrash.types
@@ -3,7 +3,7 @@ type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>;
 >Omit : Pick<T, Exclude<keyof T, K>>
 
 type Shared< // Circularly self constraining type, defered thanks to mapping
->Shared : any
+>Shared : Shared<InjectedProps, DecorationTargetProps>
 
     InjectedProps,
     DecorationTargetProps extends Shared<InjectedProps, DecorationTargetProps>