Only check when apparent type of source is a structured type

ahejlsberg · ahejlsberg · commit 2beca5c62082 · 2020-04-04T10:41:38.000-07:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -15628,7 +15628,7 @@ namespace ts {
                 //   }
                 if (result && (
                     target.flags & TypeFlags.Intersection && (isPerformingExcessPropertyChecks || isPerformingCommonPropertyChecks) ||
-                    isNonGenericObjectType(target) && source.flags & TypeFlags.Intersection && !some((<IntersectionType>source).types, t => !!(getObjectFlags(t) & ObjectFlags.NonInferrableType)) && !(getApparentType(source).flags & TypeFlags.Never))) {
+                    isNonGenericObjectType(target) && source.flags & TypeFlags.Intersection && getApparentType(source).flags & TypeFlags.StructuredType && !some((<IntersectionType>source).types, t => !!(getObjectFlags(t) & ObjectFlags.NonInferrableType)))) {
                     result &= recursiveTypeRelatedTo(source, target, reportErrors, IntersectionState.PropertyCheck);
                 }
 

Original file line number	Diff line number	Diff line change
`@@ -15628,7 +15628,7 @@ namespace ts {`
`15628`	`15628`	`// }`
`15629`	`15629`	`if (result && (`
`15630`	`15630`	`target.flags & TypeFlags.Intersection && (isPerformingExcessPropertyChecks \|\| isPerformingCommonPropertyChecks) \|\|`
`15631`		`- isNonGenericObjectType(target) && source.flags & TypeFlags.Intersection && !some((<IntersectionType>source).types, t => !!(getObjectFlags(t) & ObjectFlags.NonInferrableType)) && !(getApparentType(source).flags & TypeFlags.Never))) {`
	`15631`	`+ isNonGenericObjectType(target) && source.flags & TypeFlags.Intersection && getApparentType(source).flags & TypeFlags.StructuredType && !some((<IntersectionType>source).types, t => !!(getObjectFlags(t) & ObjectFlags.NonInferrableType)))) {`
`15632`	`15632`	`result &= recursiveTypeRelatedTo(source, target, reportErrors, IntersectionState.PropertyCheck);`
`15633`	`15633`	`}`
`15634`	`15634`